2017 |
Khalfa, S; Touzet, C EMDR therapy mechanisms explained by the Theory of neural Cognition Article de journal Journal of Traumatic Stress Disorders & Treatment, 6 (4), p. 1-7, 2017, ISSN: 2324-8947. @article{Khalfa2017, title = {EMDR therapy mechanisms explained by the Theory of neural Cognition}, author = {S. Khalfa and C. Touzet}, editor = {SciTechnol}, url = {https://www.scitechnol.com/peer-review/emdr-therapy-mechanisms-explained-by-the-theory-of-neural-cognition-JW6q.php?article_id=6825}, doi = {10.4172/2324-8947.1000179}, issn = {2324-8947}, year = {2017}, date = {2017-12-21}, journal = {Journal of Traumatic Stress Disorders & Treatment}, volume = {6}, number = {4}, pages = {1-7}, abstract = {Eye Movement Desensitization and Reprocessing (EMDR) is a therapy of choice for post-traumatic stress disorder (PTSD). The mechanism of EMDR therapy is still unknown but it is hypothesized to favor memory reconsolidation. A new learning occurs relieved from the emotional load. Based on the Theory of neural Cognition (TnC), we propose an explanation of this phenomenon that implicates hebbian synaptic plasticity, i.e., long-term potentiation (LTP) and long-term depression (LTD). The new learning is mediated by the bilateral alternating stimulations (BAS) that are essential to the EMDR therapy. These repeated BAS modify the neural traces of a traumatic memory through the incorporation of newly activated cortical columns. These activated columns form a sparse coding representation of the situation called the global state of activation (GSA). Some of these added cortical activities will eventually crystallize in a column’s activation that is able to join the current GSA, making a new GSA, i.e., a stable network of activity. This process (trauma recall and BAS) is repeated several times, and each time, the activity of new columns is being added to the current GSA, until a GSAn totally cleared of its emotional content is obtained. Each GSA is a stable network of activity which gets reinforced thanks to LTP. Each time, a lessened traumatic memory s e e e e ese mo o s e u s om e amygdalae’s involvement in the traumatic memory towards a more cognitive representation of the traumatic event, exempt from the previously associated strong negative feeling.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Eye Movement Desensitization and Reprocessing (EMDR) is a therapy of choice for post-traumatic stress disorder (PTSD). The mechanism of EMDR therapy is still unknown but it is hypothesized to favor memory reconsolidation. A new learning occurs relieved from the emotional load. Based on the Theory of neural Cognition (TnC), we propose an explanation of this phenomenon that implicates hebbian synaptic plasticity, i.e., long-term potentiation (LTP) and long-term depression (LTD). The new learning is mediated by the bilateral alternating stimulations (BAS) that are essential to the EMDR therapy. These repeated BAS modify the neural traces of a traumatic memory through the incorporation of newly activated cortical columns. These activated columns form a sparse coding representation of the situation called the global state of activation (GSA). Some of these added cortical activities will eventually crystallize in a column’s activation that is able to join the current GSA, making a new GSA, i.e., a stable network of activity. This process (trauma recall and BAS) is repeated several times, and each time, the activity of new columns is being added to the current GSA, until a GSAn totally cleared of its emotional content is obtained. Each GSA is a stable network of activity which gets reinforced thanks to LTP. Each time, a lessened traumatic memory s e e e e ese mo o s e u s om e amygdalae’s involvement in the traumatic memory towards a more cognitive representation of the traumatic event, exempt from the previously associated strong negative feeling. |
Ribot-Ciscar, Edith; Aimonetti, Jean-Marc; Azulay, Jean-Philippe Sensory training with vibration-induced kinesthetic illusions improves proprioceptive integration in patients with Parkinson’s disease. Article de journal Journal of Neurological Sciences, 383 , p. 161-165, 2017. @article{edith2017, title = {Sensory training with vibration-induced kinesthetic illusions improves proprioceptive integration in patients with Parkinson’s disease.}, author = {Edith Ribot-Ciscar and Jean-Marc Aimonetti and Jean-Philippe Azulay}, doi = {doi: 10.1016/j.jns.2017.11.016.}, year = {2017}, date = {2017-12-15}, journal = {Journal of Neurological Sciences}, volume = {383}, pages = {161-165}, abstract = {The present study investigates whether proprioceptive training, based on kinesthetic illusions, can help in re-educating the processing of muscle proprioceptive input, which is impaired in patients with Parkinson's disease (PD). The processing of proprioceptive input before and after training was evaluated by determining the error in the amplitude of voluntary dorsiflexion ankle movement (20°), induced by applying a vibration on the tendon of the gastrocnemius-soleus muscle (a vibration-induced movement error). The training consisted of the subjects focusing their attention upon a series of illusory movements of the ankle. Eleven PD patients and eleven age-matched control subjects were tested. Before training, vibration reduced dorsiflexion amplitude in controls by 4.3° (P<0.001); conversely, vibration was inefficient in PD's movement amplitude (reduction of 2.1°, P=0.20). After training, vibration significantly reduced the estimated movement amplitude in PD patients by 5.3° (P=0.01). This re-emergence of a vibration-induced error leads us to conclude that proprioceptive training, based on kinesthetic illusions, is a simple means for re-educating the processing of muscle proprioceptive input in PD patients. Such complementary training should be included in rehabilitation programs that presently focus on improving balance and motor performance.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present study investigates whether proprioceptive training, based on kinesthetic illusions, can help in re-educating the processing of muscle proprioceptive input, which is impaired in patients with Parkinson's disease (PD). The processing of proprioceptive input before and after training was evaluated by determining the error in the amplitude of voluntary dorsiflexion ankle movement (20°), induced by applying a vibration on the tendon of the gastrocnemius-soleus muscle (a vibration-induced movement error). The training consisted of the subjects focusing their attention upon a series of illusory movements of the ankle. Eleven PD patients and eleven age-matched control subjects were tested. Before training, vibration reduced dorsiflexion amplitude in controls by 4.3° (P<0.001); conversely, vibration was inefficient in PD's movement amplitude (reduction of 2.1°, P=0.20). After training, vibration significantly reduced the estimated movement amplitude in PD patients by 5.3° (P=0.01). This re-emergence of a vibration-induced error leads us to conclude that proprioceptive training, based on kinesthetic illusions, is a simple means for re-educating the processing of muscle proprioceptive input in PD patients. Such complementary training should be included in rehabilitation programs that presently focus on improving balance and motor performance. |
Marie Chancel Anne Kavounoudias, Michel Guerraz What’s left of the mirror illusion when the mirror is no longer seen? Bilateral integration of proprioceptive afferents! Article de journal Neuroscience, 362 , p. 118-226, 2017. @article{Kavounoudias2017, title = {What’s left of the mirror illusion when the mirror is no longer seen? Bilateral integration of proprioceptive afferents! }, author = {Marie Chancel, Anne Kavounoudias, Michel Guerraz}, doi = {10.1016/j.neuroscience.2017.08.036}, year = {2017}, date = {2017-08-23}, journal = {Neuroscience}, volume = {362}, pages = {118-226}, abstract = {Recent data suggest that manipulating the muscle afferents of one arm affects both ipsilateral and contralateral perceptual estimates. Here, we used the mirror paradigm to study the bimanual integration of kinesthetic muscle afferents. The reflection of a moving hand in a mirror positioned in the sagittal plane creates an illusion of symmetrical bimanual movement. Although vision clearly has a role in kinesthesia, its role in the mirror illusion might have been overestimated. Conversely, the role of bimanual integration of muscle afferents might have been underestimated. We hypothesized that muscle-proprioceptive afferents of the passively displaced arm (the image of which was reflected in the mirror) are involved in this illusion. We evoked in 19 healthy adult participants the mirror illusion by displacing passively their left arm, the image of which was reflected in the mirror. Once participants experienced the illusion that their hidden right arm was moving, we then either occluded their view of the mirror (using occlusive glasses) and/or prevent the passive left arm displacement. Participants’ illusion characteristics (duration and kinematic) under these conditions were compared with classical mirror illusion (without visual occlusion). We found that as long as the arm was still moving, the kinesthetic illusion decayed slowly after visual occlusion. These findings suggest that the mirror illusion results from the combination of visuo-proprioceptive signals from the two arms and is not purely visual in origin. Our findings also support the more general concept whereby proprioceptive afferents are integrated bilaterally for the purpose of kinesthesia during bimanual tasks. (c) 2017 IBRO. Published by Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recent data suggest that manipulating the muscle afferents of one arm affects both ipsilateral and contralateral perceptual estimates. Here, we used the mirror paradigm to study the bimanual integration of kinesthetic muscle afferents. The reflection of a moving hand in a mirror positioned in the sagittal plane creates an illusion of symmetrical bimanual movement. Although vision clearly has a role in kinesthesia, its role in the mirror illusion might have been overestimated. Conversely, the role of bimanual integration of muscle afferents might have been underestimated. We hypothesized that muscle-proprioceptive afferents of the passively displaced arm (the image of which was reflected in the mirror) are involved in this illusion. We evoked in 19 healthy adult participants the mirror illusion by displacing passively their left arm, the image of which was reflected in the mirror. Once participants experienced the illusion that their hidden right arm was moving, we then either occluded their view of the mirror (using occlusive glasses) and/or prevent the passive left arm displacement. Participants’ illusion characteristics (duration and kinematic) under these conditions were compared with classical mirror illusion (without visual occlusion). We found that as long as the arm was still moving, the kinesthetic illusion decayed slowly after visual occlusion. These findings suggest that the mirror illusion results from the combination of visuo-proprioceptive signals from the two arms and is not purely visual in origin. Our findings also support the more general concept whereby proprioceptive afferents are integrated bilaterally for the purpose of kinesthesia during bimanual tasks. (c) 2017 IBRO. Published by Elsevier Ltd. All rights reserved. |
Ackerley, Rochelle; Aimonetti, Jean-Marc; Ribot-Ciscar, Edith Emotions alter muscle proprioceptive coding of movements in humans. Article de journal Scientific Reports, 7 (1), p. 8465, 2017. @article{edith2017, title = {Emotions alter muscle proprioceptive coding of movements in humans.}, author = {Rochelle Ackerley and Jean-Marc Aimonetti and Edith Ribot-Ciscar}, doi = {10.1038/s41598-017-08721-4.}, year = {2017}, date = {2017-08-16}, journal = {Scientific Reports}, volume = {7}, number = {1}, pages = {8465}, abstract = {Emotions can evoke strong reactions that have profound influences, from gross changes in our internal environment to small fluctuations in facial muscles, and reveal our feelings overtly. Muscles contain proprioceptive afferents, informing us about our movements and regulating motor activities. Their firing reflects changes in muscle length, yet their sensitivity can be modified by the fusimotor system, as found in animals. In humans, the sensitivity of muscle afferents is modulated by cognitive processes, such as attention; however, it is unknown if emotional processes can modulate muscle feedback. Presently, we explored whether muscle afferent sensitivity adapts to the emotional situation. We recorded from single muscle afferents in the leg, using microneurography, and moved the ankle joint of participants, while they listened to evocative classical music to induce sad, neutral, or happy emotions, or sat passively (no music). We further monitored their physiological responses using skin conductance, heart rate, and electromyography measures. We found that muscle afferent firing was modified by the emotional context, especially for sad emotions, where the muscle spindle dynamic response increased. We suggest that this allows us to prime movements, where the emotional state prepares the body for consequent behaviour-appropriate reactions.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Emotions can evoke strong reactions that have profound influences, from gross changes in our internal environment to small fluctuations in facial muscles, and reveal our feelings overtly. Muscles contain proprioceptive afferents, informing us about our movements and regulating motor activities. Their firing reflects changes in muscle length, yet their sensitivity can be modified by the fusimotor system, as found in animals. In humans, the sensitivity of muscle afferents is modulated by cognitive processes, such as attention; however, it is unknown if emotional processes can modulate muscle feedback. Presently, we explored whether muscle afferent sensitivity adapts to the emotional situation. We recorded from single muscle afferents in the leg, using microneurography, and moved the ankle joint of participants, while they listened to evocative classical music to induce sad, neutral, or happy emotions, or sat passively (no music). We further monitored their physiological responses using skin conductance, heart rate, and electromyography measures. We found that muscle afferent firing was modified by the emotional context, especially for sad emotions, where the muscle spindle dynamic response increased. We suggest that this allows us to prime movements, where the emotional state prepares the body for consequent behaviour-appropriate reactions. |
Touzet, C Cognitive fatigue: an impaired cortical inhibitory replenishment Article de journal Brain Injury, 31 (12), p. 1625-1631, 2017. @article{1_168, title = {Cognitive fatigue: an impaired cortical inhibitory replenishment}, author = {C. Touzet}, url = {https://www.tandfonline.com/doi/abs/10.1080/02699052.2017.1344300?journalCode=ibij20}, doi = {10.1080/02699052.2017.1344300}, year = {2017}, date = {2017-07-27}, journal = {Brain Injury}, volume = {31}, number = {12}, pages = {1625-1631}, abstract = {The present study explores the cause of cognitive fatigue in persons with traumatic brain injury (TBI), as also in persons with Multiple Sclerosis (MS). Since cognitive fatigue shares many symptoms with chronic sleep deprivation (best described as cumulative excess wakefulness), it was hypothesized that cognitive fatigue is caused by cumulative excess wakefulness because of an impaired sleep efficacy. Recent results about the nature of sleep advocate that sleep aims primarily to replenish the efficiency of cortical inhibitory synapses. Research design: We extensively researched in the TBI and MS literature on cognitive fatigue facts that sustained, or invalidate, our hypothesis. Methods and procedures: We primary focused on TBI, but cognitive fatigue has received much more interest from the MS research community. We therefore used results from the MS literature to consolidate our TBI findings. Main outcomes and results: There are objective reasons related to TBI and MS disease to suppose that NonREM sleep’s efficacy is impaired (despite a normal duration of sleep). Conclusions: Strategies providing a more efficient NonREM sleep could demonstrate some therapeutic action against cognitive fatigue.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present study explores the cause of cognitive fatigue in persons with traumatic brain injury (TBI), as also in persons with Multiple Sclerosis (MS). Since cognitive fatigue shares many symptoms with chronic sleep deprivation (best described as cumulative excess wakefulness), it was hypothesized that cognitive fatigue is caused by cumulative excess wakefulness because of an impaired sleep efficacy. Recent results about the nature of sleep advocate that sleep aims primarily to replenish the efficiency of cortical inhibitory synapses. Research design: We extensively researched in the TBI and MS literature on cognitive fatigue facts that sustained, or invalidate, our hypothesis. Methods and procedures: We primary focused on TBI, but cognitive fatigue has received much more interest from the MS research community. We therefore used results from the MS literature to consolidate our TBI findings. Main outcomes and results: There are objective reasons related to TBI and MS disease to suppose that NonREM sleep’s efficacy is impaired (despite a normal duration of sleep). Conclusions: Strategies providing a more efficient NonREM sleep could demonstrate some therapeutic action against cognitive fatigue. |
Beaulieu, Louis-David; Massé-Alarie, Hugo; Ribot-Ciscar, Edith; Schneider, Cyril Reliability of lower limb transcranial magnetic stimulation outcomes in the ipsi- and contralesional hemispheres of adults with chronic stroke Article de journal Clinical Neurophysiology, 128 (7), p. 1290-1298, 2017. @article{Beaulieu2017b, title = {Reliability of lower limb transcranial magnetic stimulation outcomes in the ipsi- and contralesional hemispheres of adults with chronic stroke}, author = {Louis-David Beaulieu and Hugo Massé-Alarie and Edith Ribot-Ciscar and Cyril Schneider}, doi = {10.1016/j.clinph.2017.04.021}, year = {2017}, date = {2017-07-01}, journal = {Clinical Neurophysiology}, volume = {128}, number = {7}, pages = {1290-1298}, abstract = {OBJECTIVE: To investigate the ability of transcranial magnetic stimulation (TMS) outcomes in the chronic stroke population to (i) track individual plastic changes and (ii) detect differences between individuals. To this end, intrarater "test-retest" reliability (relative and absolute) was tested for the ipsilesional and contralesional hemispheres. METHODS: Thirteen participants with a unilateral stroke (≥6months ago) and sensorimotor impairments were enrolled. Single and paired-pulse TMS outcomes were obtained from the primary motor cortex (M1) representation of the tibialis anterior muscle in both hemispheres and at two sessions separated by one week. The standard error of the measurement (SEMeas), minimal detectable change (MDC) and intraclass correlation coefficient (ICC) were studied. RESULTS: Active motor threshold and latency of motor evoked potentials provided the lowest SEMeas and highest ICCs for both ipsi- and contralesional hemispheres. However, MDC were generally large, thus questioning the use of TMS outcomes to track individual plastic changes of M1. CONCLUSIONS: Our study provided supporting evidence of good to excellent intrarater reliability for a few TMS outcomes and proposed recommendations on the interpretation and the use of that knowledge in future work. SIGNIFICANCE: Psychometric properties of TMS measures should be further addressed in order to better understand how to refine their use in clinical settings.}, keywords = {}, pubstate = {published}, tppubtype = {article} } OBJECTIVE: To investigate the ability of transcranial magnetic stimulation (TMS) outcomes in the chronic stroke population to (i) track individual plastic changes and (ii) detect differences between individuals. To this end, intrarater "test-retest" reliability (relative and absolute) was tested for the ipsilesional and contralesional hemispheres. METHODS: Thirteen participants with a unilateral stroke (≥6months ago) and sensorimotor impairments were enrolled. Single and paired-pulse TMS outcomes were obtained from the primary motor cortex (M1) representation of the tibialis anterior muscle in both hemispheres and at two sessions separated by one week. The standard error of the measurement (SEMeas), minimal detectable change (MDC) and intraclass correlation coefficient (ICC) were studied. RESULTS: Active motor threshold and latency of motor evoked potentials provided the lowest SEMeas and highest ICCs for both ipsi- and contralesional hemispheres. However, MDC were generally large, thus questioning the use of TMS outcomes to track individual plastic changes of M1. CONCLUSIONS: Our study provided supporting evidence of good to excellent intrarater reliability for a few TMS outcomes and proposed recommendations on the interpretation and the use of that knowledge in future work. SIGNIFICANCE: Psychometric properties of TMS measures should be further addressed in order to better understand how to refine their use in clinical settings. |
Christophe Lopez, Maya Elzière Out-of-body experience in vestibular disorders – A prospective study of 210 patients with dizziness Article de journal Cortex, 2017. @article{Lopez2017, title = {Out-of-body experience in vestibular disorders – A prospective study of 210 patients with dizziness}, author = {Christophe Lopez, Maya Elzière}, editor = {Elsevier}, doi = {10.1016/j.cortex.2017.05.026}, year = {2017}, date = {2017-06-08}, journal = {Cortex}, abstract = {Out-of-body experiences (OBEs) are states during which people experience their centre of awareness as located outside of their physical body, along with the sensation of seeing the environment from an elevated viewpoint. OBE is encountered in epilepsy, migraine and depersonalization, and it is not an uncommon experience in the general population. Current neuroscientific models of bodily self-consciousness consider that OBE are related to a failure to integrate visual, somatosensory and vestibular signals. These models have highlighted the importance of visual-vestibular mismatch in OBE. Case reports from older clinical literature suggest that vestibular disorders may precipitate OBE, but we were lacking population-based evidence that OBE is related to vestibular disorders. The present observational, prospective study describes otoneurological, neuropsychological and phenomenological correlates of OBE in the largest sample of patients with dizziness to date (n = 210) compared to a group of age- and gender-matched controls with no history of dizziness (n = 210). We show a significantly higher occurrence of OBE in patients with dizziness (14%) than in healthy participants (5%). Most of the patients experienced OBE only after they started having dizziness for the first time. OBE in patients with dizziness were mainly related to peripheral vestibular disorders. We also identify depersonalization-derealization, depression and anxiety as the main predictors of OBE in patients with dizziness, as well as a contribution of migraine. Depersonalization-derealization was the only significant predictor of OBE in healthy controls. Altogether, our data indicate that OBE in patients with dizziness may arise from a combination of perceptual incoherence evoked by the vestibular dysfunction with psychological factors (depersonalization-derealization, depression and anxiety) and neurological factors (migraine).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Out-of-body experiences (OBEs) are states during which people experience their centre of awareness as located outside of their physical body, along with the sensation of seeing the environment from an elevated viewpoint. OBE is encountered in epilepsy, migraine and depersonalization, and it is not an uncommon experience in the general population. Current neuroscientific models of bodily self-consciousness consider that OBE are related to a failure to integrate visual, somatosensory and vestibular signals. These models have highlighted the importance of visual-vestibular mismatch in OBE. Case reports from older clinical literature suggest that vestibular disorders may precipitate OBE, but we were lacking population-based evidence that OBE is related to vestibular disorders. The present observational, prospective study describes otoneurological, neuropsychological and phenomenological correlates of OBE in the largest sample of patients with dizziness to date (n = 210) compared to a group of age- and gender-matched controls with no history of dizziness (n = 210). We show a significantly higher occurrence of OBE in patients with dizziness (14%) than in healthy participants (5%). Most of the patients experienced OBE only after they started having dizziness for the first time. OBE in patients with dizziness were mainly related to peripheral vestibular disorders. We also identify depersonalization-derealization, depression and anxiety as the main predictors of OBE in patients with dizziness, as well as a contribution of migraine. Depersonalization-derealization was the only significant predictor of OBE in healthy controls. Altogether, our data indicate that OBE in patients with dizziness may arise from a combination of perceptual incoherence evoked by the vestibular dysfunction with psychological factors (depersonalization-derealization, depression and anxiety) and neurological factors (migraine). |
Jennifer Wegrzyk Jean-Philippe Ranjeva, Alexandre Fouré Anne Kavounoudias Christophe Vilmen Jean-Pierre Mattei Maxime Guye Nicola Maffiuletti Nicolas Place David Bendahan Julien Gondin A Specific brain activation patterns associated with two neuromuscular electrical stimulation protocols Article de journal Scientific Reports, 7 (2742), 2017. @article{Wegrzyk2017, title = {Specific brain activation patterns associated with two neuromuscular electrical stimulation protocols}, author = {Jennifer Wegrzyk, Jean-Philippe Ranjeva, Alexandre Fouré, Anne Kavounoudias, Christophe Vilmen, Jean-Pierre Mattei, Maxime Guye, Nicola A. Maffiuletti, Nicolas Place, David Bendahan, Julien Gondin}, doi = {10.1038/s41598-017-03188-9}, year = {2017}, date = {2017-06-02}, journal = {Scientific Reports}, volume = {7}, number = {2742}, abstract = {The influence of neuromuscular electrical stimulation (NMES) parameters on brain activation has been scarcely investigated. We aimed at comparing two frequently used NMES protocols - designed to vary in the extent of sensory input. Whole-brain functional magnetic resonance imaging was performed in sixteen healthy subjects during wide-pulse high-frequency (WPHF, 100 Hz–1 ms) and conventional (CONV, 25 Hz–0.05 ms) NMES applied over the triceps surae. Each protocol included 20 isometric contractions performed at 10% of maximal force. Voluntary plantar flexions (VOL) were performed as control trial. Mean force was not different among the three protocols, however, total current charge was higher for WPHF than for CONV. All protocols elicited significant activations of the sensorimotor network, cerebellum and thalamus. WPHF resulted in lower deactivation in the secondary somatosensory cortex and precuneus. Bilateral thalami and caudate nuclei were hyperactivated for CONV. The modulation of the NMES parameters resulted in differently activated/deactivated regions related to total current charge of the stimulation but not to mean force. By targeting different cerebral brain regions, the two NMES protocols might allow for individually-designed rehabilitation training in patients who can no longer execute voluntary movements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The influence of neuromuscular electrical stimulation (NMES) parameters on brain activation has been scarcely investigated. We aimed at comparing two frequently used NMES protocols - designed to vary in the extent of sensory input. Whole-brain functional magnetic resonance imaging was performed in sixteen healthy subjects during wide-pulse high-frequency (WPHF, 100 Hz–1 ms) and conventional (CONV, 25 Hz–0.05 ms) NMES applied over the triceps surae. Each protocol included 20 isometric contractions performed at 10% of maximal force. Voluntary plantar flexions (VOL) were performed as control trial. Mean force was not different among the three protocols, however, total current charge was higher for WPHF than for CONV. All protocols elicited significant activations of the sensorimotor network, cerebellum and thalamus. WPHF resulted in lower deactivation in the secondary somatosensory cortex and precuneus. Bilateral thalami and caudate nuclei were hyperactivated for CONV. The modulation of the NMES parameters resulted in differently activated/deactivated regions related to total current charge of the stimulation but not to mean force. By targeting different cerebral brain regions, the two NMES protocols might allow for individually-designed rehabilitation training in patients who can no longer execute voluntary movements. |
David Péricat Anne Farina, Emilie Agavnian-Couquiaud Christian Chabbert Brahim Tighilet Complete and irreversible unilateral vestibular loss: A novel rat modelof vestibular pathology Article de journal Journal of Neuroscience Methods, 283 , p. 83-91, 2017. @article{Pericat2017, title = {Complete and irreversible unilateral vestibular loss: A novel rat modelof vestibular pathology}, author = {David Péricat, Anne Farina, Emilie Agavnian-Couquiaud, Christian Chabbert, Brahim Tighilet}, doi = {10.1016/j.jneumeth.2017.04.001}, year = {2017}, date = {2017-04-01}, journal = {Journal of Neuroscience Methods}, volume = {283}, pages = {83-91}, abstract = {Background: Both basic and applied studies on the pathophysiology of vestibular disorders are currentlyimpaired by the lack of animal models of controlled vestibular damages. New methods: In the present study, we describe the procedure to achieve a surgical unilateral vestibularneurectomy (UVN) in the rat and evaluate its functional consequences. This procedure is suitable forreproducing a unilateral, sudden and definitive vestibular areflexia. Results: Proper induction of a UVN induces a severe vestibular syndrome, which mimics vestibu-lar disorders encountered in humans. This model is also used clinically in the surgical treatment ofpharmacological intractable Meniere’s disease. Comparison with existing methods unilateral vestibularneurectomy has been essentially used in other species such as cats, monkeys and humans. The currentstudy describes this technique in rats. Conclusion: This experimental model is particularly adapted to study the restoration kinetics of vestibularfunction after removal of peripheral inputs. It is also suitable for determining the neurochemical andmolecular mechanisms underlying central compensation processes, as well as to check for the efficacy ofdrugs with potent antivertigo properties. Finally, UVN is an acknowledged model of postlesional plasticityinvolving original processes such as reactive neurogenesis in the vestibular nuclei. © 2017 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Both basic and applied studies on the pathophysiology of vestibular disorders are currentlyimpaired by the lack of animal models of controlled vestibular damages. New methods: In the present study, we describe the procedure to achieve a surgical unilateral vestibularneurectomy (UVN) in the rat and evaluate its functional consequences. This procedure is suitable forreproducing a unilateral, sudden and definitive vestibular areflexia. Results: Proper induction of a UVN induces a severe vestibular syndrome, which mimics vestibu-lar disorders encountered in humans. This model is also used clinically in the surgical treatment ofpharmacological intractable Meniere’s disease. Comparison with existing methods unilateral vestibularneurectomy has been essentially used in other species such as cats, monkeys and humans. The currentstudy describes this technique in rats. Conclusion: This experimental model is particularly adapted to study the restoration kinetics of vestibularfunction after removal of peripheral inputs. It is also suitable for determining the neurochemical andmolecular mechanisms underlying central compensation processes, as well as to check for the efficacy ofdrugs with potent antivertigo properties. Finally, UVN is an acknowledged model of postlesional plasticityinvolving original processes such as reactive neurogenesis in the vestibular nuclei. © 2017 Elsevier B.V. All rights reserved. |
Laurent Pezard Karyn Dobab, Annick Lesned Jean-Louis Nandrinob Quantifying the dynamics of emotional expressions in family therapy of patients with anorexia nervosa Article de journal Psychiatry Research, 253 , p. 49-57, 2017. @article{Pezard2017, title = {Quantifying the dynamics of emotional expressions in family therapy of patients with anorexia nervosa}, author = {Laurent Pezard, Karyn Dobab, Annick Lesned, Jean-Louis Nandrinob}, doi = {10.1016/j.psychres.2017.03.044}, year = {2017}, date = {2017-03-22}, journal = {Psychiatry Research}, volume = {253}, pages = {49-57}, abstract = {Emotional interactions have been considered dynamical processes involved in the affective life of humans and their disturbances may induce mental disorders. Most studies of emotional interactions have focused on dyadic behaviors or self-reports of emotional states but neglected the dynamical processes involved in family therapy. The main objective of this study is to quantify the dynamics of emotional expressions and their changes using the family therapy of patients with anorexia nervosa as an example. Nonlinear methods characterize the variability of the dynamics at the level of the whole therapeutic system and reciprocal influence between the participants during family therapy. Results show that the variability of the dynamics is higher at the end of the therapy than at the beginning. The reciprocal influences between therapist and each member of the family and between mother and patient decrease with the course of family therapy. Our results support the development of new interpersonal strategies of emotion regulation during family therapy. The quantification of emotional dynamics can help understanding the emotional processes underlying psychopathology and evaluating quantitatively the changes achieved by the therapeutic intervention.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Emotional interactions have been considered dynamical processes involved in the affective life of humans and their disturbances may induce mental disorders. Most studies of emotional interactions have focused on dyadic behaviors or self-reports of emotional states but neglected the dynamical processes involved in family therapy. The main objective of this study is to quantify the dynamics of emotional expressions and their changes using the family therapy of patients with anorexia nervosa as an example. Nonlinear methods characterize the variability of the dynamics at the level of the whole therapeutic system and reciprocal influence between the participants during family therapy. Results show that the variability of the dynamics is higher at the end of the therapy than at the beginning. The reciprocal influences between therapist and each member of the family and between mother and patient decrease with the course of family therapy. Our results support the development of new interpersonal strategies of emotion regulation during family therapy. The quantification of emotional dynamics can help understanding the emotional processes underlying psychopathology and evaluating quantitatively the changes achieved by the therapeutic intervention. |
Beaulieu, Louis-David; Massé-Alarie, Hugo; Camiré-Bernier, Samuel; Ribot-Ciscar, Édith; Schneider, Cyril After-effects of peripheral neurostimulation on brain plasticity and ankle function in chronic stroke: The role of afferents recruited Article de journal Clinical Neurophysiology, 2017. @article{Beaulieu2017, title = {After-effects of peripheral neurostimulation on brain plasticity and ankle function in chronic stroke: The role of afferents recruited}, author = {Louis-David Beaulieu and Hugo Massé-Alarie and Samuel Camiré-Bernier and Édith Ribot-Ciscar and Cyril Schneider}, doi = {10.1016/j.neucli.2017.02.003}, year = {2017}, date = {2017-03-15}, journal = {Clinical Neurophysiology}, abstract = {AIMS OF THE STUDY: This study tested the after-effects of neuromuscular electrical stimulation (NMES), repetitive peripheral magnetic stimulation (rPMS) and muscle tendon vibration (VIB) on brain plasticity and sensorimotor impairments in chronic stroke to investigate whether different results could depend on the nature of afferents recruited by each technique. MATERIALS AND METHODS: Fifteen people with chronic stroke participated in five sessions (one per week). Baseline measures were collected in session one, then, each participant received 4 randomly ordered interventions (NMES, rPMS, VIB and a 'control' intervention of exercises). Interventions were applied to the paretic ankle muscles and parameters of application were matched as closely as possible. Standardized clinical measures of the ankle function on the paretic side and transcranial magnetic stimulation (TMS) outcomes of both primary motor cortices (M1) were collected at pre- and post-application of each intervention. RESULTS: The ankle muscle strength was significantly improved by rPMS and VIB (P≤0.02). rPMS influenced M1 excitability (increase in the contralesional hemisphere, P=0.03) and inhibition (decrease in both hemispheres, P≤0.04). The group mean of a few clinical outcomes improved across sessions, i.e. independently of the order of interventions. Some TMS outcomes at baseline could predict the responsiveness to rPMS and VIB. CONCLUSION: This original study suggests that rPMS and VIB were efficient to drive M1 plasticity and sensorimotor improvements, likely via massive inflows of 'pure' proprioceptive information generated. Usefulness of some TMS outcomes to predict which intervention a patient could be more responsive to should be further tested in future studies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } AIMS OF THE STUDY: This study tested the after-effects of neuromuscular electrical stimulation (NMES), repetitive peripheral magnetic stimulation (rPMS) and muscle tendon vibration (VIB) on brain plasticity and sensorimotor impairments in chronic stroke to investigate whether different results could depend on the nature of afferents recruited by each technique. MATERIALS AND METHODS: Fifteen people with chronic stroke participated in five sessions (one per week). Baseline measures were collected in session one, then, each participant received 4 randomly ordered interventions (NMES, rPMS, VIB and a 'control' intervention of exercises). Interventions were applied to the paretic ankle muscles and parameters of application were matched as closely as possible. Standardized clinical measures of the ankle function on the paretic side and transcranial magnetic stimulation (TMS) outcomes of both primary motor cortices (M1) were collected at pre- and post-application of each intervention. RESULTS: The ankle muscle strength was significantly improved by rPMS and VIB (P≤0.02). rPMS influenced M1 excitability (increase in the contralesional hemisphere, P=0.03) and inhibition (decrease in both hemispheres, P≤0.04). The group mean of a few clinical outcomes improved across sessions, i.e. independently of the order of interventions. Some TMS outcomes at baseline could predict the responsiveness to rPMS and VIB. CONCLUSION: This original study suggests that rPMS and VIB were efficient to drive M1 plasticity and sensorimotor improvements, likely via massive inflows of 'pure' proprioceptive information generated. Usefulness of some TMS outcomes to predict which intervention a patient could be more responsive to should be further tested in future studies. |
Youssef Adel Gaston Hilkhuysen, Arnaud Noreña Yves Cazals Stéphane Roman Olivier Macherey Forward Masking in Cochlear Implant Users: Electrophysiological and Psychophysical Data Using Pulse Train Maskers Article de journal JARO, 18 (3), p. 495-512, 2017. @article{Adel2017, title = {Forward Masking in Cochlear Implant Users: Electrophysiological and Psychophysical Data Using Pulse Train Maskers}, author = {Youssef Adel, Gaston Hilkhuysen, Arnaud Noreña, Yves Cazals, Stéphane Roman, Olivier Macherey}, doi = {10.1007/s10162-016-0613-5}, year = {2017}, date = {2017-02-21}, journal = {JARO}, volume = {18}, number = {3}, pages = {495-512}, abstract = {Electrical stimulation of auditory nerve fibers using cochlear implants (CI) shows psychophysical forward masking (pFM) up to several hundreds of millisec- onds. By contrast, recovery of electrically evoked compound action potentials (eCAPs) from forward masking (eFM) was shown to be more rapid, with time constants no greater than a few milliseconds. These discrepancies suggested two main contributors to pFM: a rapid-recovery process due to refractory properties of the auditory nerve and a slow-recovery process arising from more central structures. In the present study, we investigate whether the use of different maskers between eCAP and psychophysical measures, specifically single-pulse versus pulse train maskers, may have been a source of confound. In experiment 1, we measured eFM using the following: a single-pulse masker, a 300-ms low-rate pulse train masker (LTM, 250 pps), and a 300-ms high-rate pulse train masker (HTM, 5000 pps). The maskers were presented either at same physical current (Φ) or at same perceptual (Ψ) level corre- sponding to comfortable loudness. Responses to a single-pulse probe were measured for masker-probe intervals ranging from 1 to 512 ms. Recovery from masking was much slower for pulse trains than for the single-pulse masker. When presented at Φ level, HTM produced more and longer-lasting masking than LTM. However, results were inconsistent when LTM and HTM were compared at Ψ level. In experiment 2, masked detection thresholds of single-pulse probes were measured using the same pulse train masker conditions. In line with our eFM findings, masked thresholds for HTM were higher than those for LTM at Φ level. However, the opposite result was found when the pulse trains were presented at Ψ level. Our results confirm the presence of slow-recovery phenomena at the level of the auditory nerve in CI users, as previously shown in animal studies. Inconsis- tencies between eFM and pFM results, despite using the same masking conditions, further underline the importance of comparing electrophysiological and psychophysical measures with identical stimulation paradigms.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Electrical stimulation of auditory nerve fibers using cochlear implants (CI) shows psychophysical forward masking (pFM) up to several hundreds of millisec- onds. By contrast, recovery of electrically evoked compound action potentials (eCAPs) from forward masking (eFM) was shown to be more rapid, with time constants no greater than a few milliseconds. These discrepancies suggested two main contributors to pFM: a rapid-recovery process due to refractory properties of the auditory nerve and a slow-recovery process arising from more central structures. In the present study, we investigate whether the use of different maskers between eCAP and psychophysical measures, specifically single-pulse versus pulse train maskers, may have been a source of confound. In experiment 1, we measured eFM using the following: a single-pulse masker, a 300-ms low-rate pulse train masker (LTM, 250 pps), and a 300-ms high-rate pulse train masker (HTM, 5000 pps). The maskers were presented either at same physical current (Φ) or at same perceptual (Ψ) level corre- sponding to comfortable loudness. Responses to a single-pulse probe were measured for masker-probe intervals ranging from 1 to 512 ms. Recovery from masking was much slower for pulse trains than for the single-pulse masker. When presented at Φ level, HTM produced more and longer-lasting masking than LTM. However, results were inconsistent when LTM and HTM were compared at Ψ level. In experiment 2, masked detection thresholds of single-pulse probes were measured using the same pulse train masker conditions. In line with our eFM findings, masked thresholds for HTM were higher than those for LTM at Φ level. However, the opposite result was found when the pulse trains were presented at Ψ level. Our results confirm the presence of slow-recovery phenomena at the level of the auditory nerve in CI users, as previously shown in animal studies. Inconsis- tencies between eFM and pFM results, despite using the same masking conditions, further underline the importance of comparing electrophysiological and psychophysical measures with identical stimulation paradigms. |
SANDIE THOMATY LAURENT PEZARD, CHRISTIAN XERRI JEAN-MICHEL BREZUN ACUTE GRANULOCYTE MACROPHAGE-COLONY STIMULATING FACTOR TREATMENT MODULATES NEUROINFLAMMATORY PROCESSES AND PROMOTES TACTILE RECOVERY AFTER SPINAL CORD INJURY Article de journal Neuroscience, 349 , p. 144-164, 2017. @article{Thomaty2017, title = {ACUTE GRANULOCYTE MACROPHAGE-COLONY STIMULATING FACTOR TREATMENT MODULATES NEUROINFLAMMATORY PROCESSES AND PROMOTES TACTILE RECOVERY AFTER SPINAL CORD INJURY}, author = {SANDIE THOMATY, LAURENT PEZARD, CHRISTIAN XERRI, JEAN-MICHEL BREZUN}, doi = {10.1016/j.neuroscience.2017.02.035}, year = {2017}, date = {2017-02-17}, journal = {Neuroscience}, volume = {349}, pages = {144-164}, abstract = {Neuroinflammation is known to play a key role in the prognosis of functional recovery after spinal cord injury (SCI). The involvement of microglial and mast cells in early and late stages of inflammation has been receiving increasing attention. This study was aimed at determining the influence of a pro-inflammatory cytokine, the granulocyte macrophage-colony stimulating factor (GM-CSF), on microglia and mast cell activation, glial scar formation and functional recovery following SCI. Rats were randomly injected with saline or GM-CSF one hour after a C4–C5 mediolateral hemisection. To assess functional impairment and recovery, the rats were subjected to sensorimotor tasks for one month. Then, responses evoked by forepaw stimulation in the primary somatosensory cortex were recorded. We also quantified the changes in GM-CSF, IL-1b, IL-6 and BDNF levels, the gliosis and lesion volume as well as microglial and mast cell density, and mast cell surface. Our findings show that GM-CSF promotes cortical reactivation and recovery of tactile abilities, whereas it does not influence motor performances. A transient decrease in pro-inflammatory cytokines after GM-CSF treatment was also observed, whereas the endogenous GM-CSF level was unchanged. While the beneficial role of GM-CSF in reducing glial scar is confirmed, our findings reveal that neuroinflammatory events mediated by microglial and mast cells as well as the alteration of IL-1b and IL-6 levels are paralleled with an improvement in tactile recovery. These mechanisms could limit the duration and intensity of homeostatic imbalance and promote the plasticity of spared tissues. 2017 IBRO. Published by Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Neuroinflammation is known to play a key role in the prognosis of functional recovery after spinal cord injury (SCI). The involvement of microglial and mast cells in early and late stages of inflammation has been receiving increasing attention. This study was aimed at determining the influence of a pro-inflammatory cytokine, the granulocyte macrophage-colony stimulating factor (GM-CSF), on microglia and mast cell activation, glial scar formation and functional recovery following SCI. Rats were randomly injected with saline or GM-CSF one hour after a C4–C5 mediolateral hemisection. To assess functional impairment and recovery, the rats were subjected to sensorimotor tasks for one month. Then, responses evoked by forepaw stimulation in the primary somatosensory cortex were recorded. We also quantified the changes in GM-CSF, IL-1b, IL-6 and BDNF levels, the gliosis and lesion volume as well as microglial and mast cell density, and mast cell surface. Our findings show that GM-CSF promotes cortical reactivation and recovery of tactile abilities, whereas it does not influence motor performances. A transient decrease in pro-inflammatory cytokines after GM-CSF treatment was also observed, whereas the endogenous GM-CSF level was unchanged. While the beneficial role of GM-CSF in reducing glial scar is confirmed, our findings reveal that neuroinflammatory events mediated by microglial and mast cells as well as the alteration of IL-1b and IL-6 levels are paralleled with an improvement in tactile recovery. These mechanisms could limit the duration and intensity of homeostatic imbalance and promote the plasticity of spared tissues. 2017 IBRO. Published by Elsevier Ltd. All rights reserved. |
Thomas E. Fuller Haula F. Haider, Dimitris Kikidis Alec Lapira Birgit Mazurek Arnaud Norena Sarah Rabau Rachelle Lardinois Christopher Cederroth Niklas Edvall Petra Brueggemann Susanne Rosing Anestis Kapandais Dorte Lungaard Derek Hoare Rilana Cima R K G N J F F Different Teams, Same Conclusions? A Systematic Review of Existing Clinical Guidelines for the Assessment and Treatment of Tinnitus in Adults Article de journal frontiers in Psychology, 8 (206), 2017. @article{Fuller2017, title = {Different Teams, Same Conclusions? A Systematic Review of Existing Clinical Guidelines for the Assessment and Treatment of Tinnitus in Adults}, author = {Thomas E. Fuller, Haula F. Haider, Dimitris Kikidis, Alec Lapira, Birgit Mazurek, Arnaud Norena, Sarah Rabau, Rachelle Lardinois, Christopher R. Cederroth, Niklas K. Edvall, Petra G. Brueggemann, Susanne N. Rosing, Anestis Kapandais, Dorte Lungaard, Derek J. Hoare, Rilana F. F Cima}, doi = {10.3389/fpsyg.2017.00206}, year = {2017}, date = {2017-02-17}, journal = {frontiers in Psychology}, volume = {8}, number = {206}, abstract = {Background: Though clinical guidelines for assessment and treatment of chronic subjective tinnitus do exist, a comprehensive review of those guidelines has not been performed. The objective of this review was to identify current clinical guidelines, and compare their recommendations for the assessment and treatment of subjective tinnitus in adults. Method: We systematically searched a range of sources for clinical guidelines (as defined by the Institute of Medicine, United States) for the assessment and/or treatment of subjective tinnitus in adults. No restrictions on language or year of publication were applied to guidelines. Results: Clinical guidelines from Denmark, Germany, Sweden, The Netherlands, and the United States were included in the review. There was a high level of consistency across the guidelines with regard to recommendations for audiometric assessment, physical examination, use of a validated questionnaire(s) to assess tinnitus related distress, and referral to a psychologist when required. Cognitive behavioral treatment for tinnitus related distress, use of hearing aids in instances of hearing loss and recommendations against the use of medicines were consistent across the included guidelines. Differences between the guidelines centered on the use of imaging in assessment procedures and sound therapy as a form of treatment for tinnitus distress respectively. Conclusion: Given the level of commonality across tinnitus guidelines from different countries the development of a European guideline for the assessment and treatment of subjective tinnitus in adults seems feasible. This guideline would have the potential to benefit the large number of clinicians in countries where clinical guidelines do not yet exist, and would support standardization of treatment for patients across Europe.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background: Though clinical guidelines for assessment and treatment of chronic subjective tinnitus do exist, a comprehensive review of those guidelines has not been performed. The objective of this review was to identify current clinical guidelines, and compare their recommendations for the assessment and treatment of subjective tinnitus in adults. Method: We systematically searched a range of sources for clinical guidelines (as defined by the Institute of Medicine, United States) for the assessment and/or treatment of subjective tinnitus in adults. No restrictions on language or year of publication were applied to guidelines. Results: Clinical guidelines from Denmark, Germany, Sweden, The Netherlands, and the United States were included in the review. There was a high level of consistency across the guidelines with regard to recommendations for audiometric assessment, physical examination, use of a validated questionnaire(s) to assess tinnitus related distress, and referral to a psychologist when required. Cognitive behavioral treatment for tinnitus related distress, use of hearing aids in instances of hearing loss and recommendations against the use of medicines were consistent across the included guidelines. Differences between the guidelines centered on the use of imaging in assessment procedures and sound therapy as a form of treatment for tinnitus distress respectively. Conclusion: Given the level of commonality across tinnitus guidelines from different countries the development of a European guideline for the assessment and treatment of subjective tinnitus in adults seems feasible. This guideline would have the potential to benefit the large number of clinicians in countries where clinical guidelines do not yet exist, and would support standardization of treatment for patients across Europe. |
Angela Callejo Amandine Durochat, Stéphanie Bressieux Aurélie Saleur Christian Chabbert Ivan Domènech Juan Jordi Llorens Sophie Gaboyard-Niay Dose-dependent cochlear and vestibular toxicity of trans-tympanic cisplatin in the rat Article de journal NeuroToxicology, 60 , p. 1-9, 2017. @article{Callejo2017, title = {Dose-dependent cochlear and vestibular toxicity of trans-tympanic cisplatin in the rat}, author = {Angela Callejo, Amandine Durochat, Stéphanie Bressieux, Aurélie Saleur, Christian Chabbert, Ivan Domènech Juan, Jordi Llorens, Sophie Gaboyard-Niay}, doi = {10.1016/j.neuro.2017.02.007}, year = {2017}, date = {2017-02-10}, journal = {NeuroToxicology}, volume = {60}, pages = {1-9}, abstract = {In vivo studies are needed to study cisplatin ototoxicity and to evaluate candidate protective treatments. Rats and mice are the preferred species for toxicological and pharmacological pre-clinical research, but systemic administration of cisplatin causes high morbidity in these species. We hypothesized that trans- tympanic administration of cisplatin would provide a good model for studying its auditory and vestibular toxicity in the rat. Cisplatin was administered by the trans-tympanic route in one ear (50 ml, 0.5–2 mg/ml) of rats of both sexes and two different strains. Cochlear toxicity was corroborated by histological means. Vestibular toxicity was demonstrated by behavioral and histological analysis. Cisplatin concentrations were assessed in inner ear after trans-tympanic and i.v. administration. In all experiments, no lethality and only scant body weight loss were recorded. Cisplatin caused dose-dependent cochlear toxicity, as demonstrated by hair cell counts in the apical and middle turns of the cochlea, and vestibular toxicity, as demonstrated by behavioral analysis and hair cell counts in utricles. High concentrations of cisplatin were found in the inner ear after trans-tympanic administration. In comparison, i.v. administration resulted in lower inner ear concentrations. We conclude that trans-tympanic administration provides an easy, reproducible and safe model to study the cochlear and vestibular toxicity of cisplatin in the rat. This route of exposure may be useful to address particular questions on cisplatin induced ototoxicity and to test candidate protective treatments. © 2017 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In vivo studies are needed to study cisplatin ototoxicity and to evaluate candidate protective treatments. Rats and mice are the preferred species for toxicological and pharmacological pre-clinical research, but systemic administration of cisplatin causes high morbidity in these species. We hypothesized that trans- tympanic administration of cisplatin would provide a good model for studying its auditory and vestibular toxicity in the rat. Cisplatin was administered by the trans-tympanic route in one ear (50 ml, 0.5–2 mg/ml) of rats of both sexes and two different strains. Cochlear toxicity was corroborated by histological means. Vestibular toxicity was demonstrated by behavioral and histological analysis. Cisplatin concentrations were assessed in inner ear after trans-tympanic and i.v. administration. In all experiments, no lethality and only scant body weight loss were recorded. Cisplatin caused dose-dependent cochlear toxicity, as demonstrated by hair cell counts in the apical and middle turns of the cochlea, and vestibular toxicity, as demonstrated by behavioral analysis and hair cell counts in utricles. High concentrations of cisplatin were found in the inner ear after trans-tympanic administration. In comparison, i.v. administration resulted in lower inner ear concentrations. We conclude that trans-tympanic administration provides an easy, reproducible and safe model to study the cochlear and vestibular toxicity of cisplatin in the rat. This route of exposure may be useful to address particular questions on cisplatin induced ototoxicity and to test candidate protective treatments. © 2017 Elsevier B.V. All rights reserved. |
van Diane Deroualle Michel Toupet, Christian Nechel Ulla Duquesne Charlotte Hautefort Christophe Lopez Anchoring the Self to the Body in Bilateral Vestibular Failure Article de journal PLoS ONE, 12 (1), 2017. @article{Deroualle2017, title = {Anchoring the Self to the Body in Bilateral Vestibular Failure}, author = {Diane Deroualle, Michel Toupet, Christian van Nechel, Ulla Duquesne, Charlotte Hautefort, Christophe Lopez }, editor = {Michel Botbol, Universite de Bretagne Occidentale, FRANCE}, doi = {10.1371/journal.pone.0170488}, year = {2017}, date = {2017-01-20}, journal = {PLoS ONE}, volume = {12}, number = {1}, abstract = {Recent findings suggest that vestibular information plays a significant role in anchoring the self to the body. Out-of-body experiences of neurological origin are frequently associated with vestibular sensations, and galvanic vestibular stimulation in healthy participants anchors the self to the body. Here, we provide the first objective measures of anchoring the self to the body in chronic bilateral vestibular failure (BVF). We compared 23 patients with idiopathic BVF to 23 healthy participants in a series of experiments addressing several aspects of visuo-spatial perspective taking and embodiment. In Experiment 1, participants were involved in a virtual “dot-counting task” from their own perspective or the perspective of a distant avatar, to measure implicit and explicit perspective taking, respectively. In both groups, response times increased similarly when the avatar’s and participant’s viewpoint differed, for both implicit and explicit perspective taking. In Experiment 2, participants named ambiguous letters (such as “b” or “q”) traced on their forehead that could be perceived from an internal or external perspective. The frequency of perceiving ambiguous letters from an internal perspective was similar in both groups. In Experiment 3, participants completed a questionnaire measuring the experienced self/body and self/environment “closeness”. Both groups reported a similar embodied experience. Altogether, our data show that idiopathic BVF does not change implicit and explicit perspective taking nor subjective anchoring of the self to the body. Our negative findings offer insight into the multisensory mechanisms of embodiment. Only acute peripheral vestibular disorders and neurological disorders in vestibular brain areas (characterized by strong multisensory conflicts) may evoke disembodied experiences.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recent findings suggest that vestibular information plays a significant role in anchoring the self to the body. Out-of-body experiences of neurological origin are frequently associated with vestibular sensations, and galvanic vestibular stimulation in healthy participants anchors the self to the body. Here, we provide the first objective measures of anchoring the self to the body in chronic bilateral vestibular failure (BVF). We compared 23 patients with idiopathic BVF to 23 healthy participants in a series of experiments addressing several aspects of visuo-spatial perspective taking and embodiment. In Experiment 1, participants were involved in a virtual “dot-counting task” from their own perspective or the perspective of a distant avatar, to measure implicit and explicit perspective taking, respectively. In both groups, response times increased similarly when the avatar’s and participant’s viewpoint differed, for both implicit and explicit perspective taking. In Experiment 2, participants named ambiguous letters (such as “b” or “q”) traced on their forehead that could be perceived from an internal or external perspective. The frequency of perceiving ambiguous letters from an internal perspective was similar in both groups. In Experiment 3, participants completed a questionnaire measuring the experienced self/body and self/environment “closeness”. Both groups reported a similar embodied experience. Altogether, our data show that idiopathic BVF does not change implicit and explicit perspective taking nor subjective anchoring of the self to the body. Our negative findings offer insight into the multisensory mechanisms of embodiment. Only acute peripheral vestibular disorders and neurological disorders in vestibular brain areas (characterized by strong multisensory conflicts) may evoke disembodied experiences. |
2016 |
Gaboyard-Niay Sophie Cécile Travo, Aurélie Saleur Audrey Broussy Aurore Brugeaud Christian Chabbert. Correlation between afferent rearrangements and behavioral deficits after local excitotoxic insult in the mammal vestibule: an animal model of vertigo symptoms? Article de journal Disease Models and Mechanisms , 9 , p. 1181-1192, 2016. @article{2016b, title = {Correlation between afferent rearrangements and behavioral deficits after local excitotoxic insult in the mammal vestibule: an animal model of vertigo symptoms? }, author = {Gaboyard-Niay Sophie, Cécile Travo, Aurélie Saleur, Audrey Broussy, Aurore Brugeaud, Christian Chabbert. }, editor = {The Company of Biologists}, year = {2016}, date = {2016-11-01}, journal = {Disease Models and Mechanisms }, volume = {9}, pages = {1181-1192}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
PABAN, Veronique; LORIOD, Béatrice; VILLARD, Claude; BUEE, Luc; BLUM, David; PIETROPAOLO, Susanna; CHO, Yoon H; GORY-FAURE, Sylvie; MANSOUR, Elodie; Alescio-Lautier, Béatrice Omics analysis of mouse brain models of human diseases (in press) Article de journal Gene, 2016. @article{Paban2016, title = {Omics analysis of mouse brain models of human diseases (in press)}, author = {Veronique PABAN and Béatrice LORIOD and Claude VILLARD and Luc BUEE and David BLUM and Susanna PIETROPAOLO and Yoon H. CHO and Sylvie GORY-FAURE and Elodie MANSOUR and Béatrice Alescio-Lautier}, year = {2016}, date = {2016-10-25}, journal = {Gene}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Paban, Veronique; Valable, Samuel; Baril, Nathalie; Gilbert, Valerie; Chambon, Caroline; Alescio-Lautier, Béatrice Neuronal and glial changes in rat hippocampal formation after cholinergic deafferentation (in press) Article de journal Journal of Biomolecular Research & Therapeutics, 2016. @article{Paban2016b, title = {Neuronal and glial changes in rat hippocampal formation after cholinergic deafferentation (in press)}, author = {Veronique Paban and Samuel Valable and Nathalie Baril and Valerie Gilbert and Caroline Chambon and Béatrice Alescio-Lautier}, year = {2016}, date = {2016-10-03}, journal = {Journal of Biomolecular Research & Therapeutics}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
VERDONK, Charles; ALESCIO-LAUTIER, Béatrice; PABAN, Véronique; CHAMBON, Caroline; FERRER, Marie-Hélène; TROUSSELARD, Marion Evaluation cognitive de la disposition Mindfulness. Approche expérimentale classique et perspectives d'une approche intégrative (sous presse) Article de journal L'Evolution Psychiatrique, 2016. @article{Verdonk2016, title = {Evaluation cognitive de la disposition Mindfulness. Approche expérimentale classique et perspectives d'une approche intégrative (sous presse)}, author = {Charles VERDONK and Béatrice ALESCIO-LAUTIER and Véronique PABAN and Caroline CHAMBON and Marie-Hélène FERRER and Marion TROUSSELARD}, year = {2016}, date = {2016-10-01}, journal = {L'Evolution Psychiatrique}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Christian, CHABBERT Principles of vestibular pharmacotherapy Article de journal Handbok of Clinical Neurology, 137 , p. 207-218, 2016. @article{2016, title = {Principles of vestibular pharmacotherapy}, author = {CHABBERT Christian}, editor = {JM Furman & T Lempert Elsevier}, year = {2016}, date = {2016-10-01}, journal = {Handbok of Clinical Neurology}, volume = {137}, pages = {207-218}, abstract = {This volume of the Handbook of Clinical Neurology, entitled Neuro-otology, aims to provide an update to Volume 9, Clinical Neurophysiology of the Vestibular System, with a slightly different focus. The intended audience for this volume includes primarily clinical neurologists who wish to know the most current established information related to dizziness and disequilibrium from a clinical, yet scholarly, perspective. The volume will be divided into three sections including Basic Aspects, Diagnostic and Therapeutic Management, and Neuro-otologic Disorders. A group of internationally acclaimed authors will represent a broad spectrum of areas of expertise, chosen for their ability to write clearly and concisely with an eye toward a clinical audience. The Basic Aspects section will be brief and will cover that material necessary for understanding later material. The Diagnostic and Therapeutic Management section will cover all of the essential topics in the evaluation and treatment of patients with dizziness and disequilibrium. The section on Neuro-otologic Disorders will be the largest portion of the volume and will address every major diagnostic category in the field. This volume of the handbook will set the new standard for comprehensive multi-authored textbooks in the field of neuro-otology.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This volume of the Handbook of Clinical Neurology, entitled Neuro-otology, aims to provide an update to Volume 9, Clinical Neurophysiology of the Vestibular System, with a slightly different focus. The intended audience for this volume includes primarily clinical neurologists who wish to know the most current established information related to dizziness and disequilibrium from a clinical, yet scholarly, perspective. The volume will be divided into three sections including Basic Aspects, Diagnostic and Therapeutic Management, and Neuro-otologic Disorders. A group of internationally acclaimed authors will represent a broad spectrum of areas of expertise, chosen for their ability to write clearly and concisely with an eye toward a clinical audience. The Basic Aspects section will be brief and will cover that material necessary for understanding later material. The Diagnostic and Therapeutic Management section will cover all of the essential topics in the evaluation and treatment of patients with dizziness and disequilibrium. The section on Neuro-otologic Disorders will be the largest portion of the volume and will address every major diagnostic category in the field. This volume of the handbook will set the new standard for comprehensive multi-authored textbooks in the field of neuro-otology. |
PABAN, Veronique; OGIER, Michael; CHAMBON, Caroline; FERNANDEZ, Nicolas; DAVIDSSON, Johan; RISLING, Marten; ALESCIO-LAUTIER, Béatrice Molecular Gene Expression Following Blunt and Rotational Models of Traumatic Brain Injury Parallel Injuries Associated with Stroke and Depression (in press) Article de journal Journal of Translational Science, 2016. @article{Paban2016b, title = {Molecular Gene Expression Following Blunt and Rotational Models of Traumatic Brain Injury Parallel Injuries Associated with Stroke and Depression (in press)}, author = {Veronique PABAN and Michael OGIER and Caroline CHAMBON and Nicolas FERNANDEZ and Johan DAVIDSSON and Marten RISLING and Béatrice ALESCIO-LAUTIER}, year = {2016}, date = {2016-09-05}, journal = {Journal of Translational Science}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Chancel, M; Blanchard, C; Guerra, M; Montagnini, A; Kavounoudias, A Optimal visuotactile integration for velocity discrimination of self-hand movements Article de journal Journal of Neurophysiology, 2016. @article{Chancel2016, title = {Optimal visuotactile integration for velocity discrimination of self-hand movements}, author = {M. Chancel and C. Blanchard and M. Guerra and A. Montagnini and A. Kavounoudias}, doi = {10.1152/jn.00883.2015}, year = {2016}, date = {2016-09-01}, journal = {Journal of Neurophysiology}, abstract = {Illusory hand movements can be elicited by a textured disk or a visual pattern rotating under one's hand, while proprioceptive inputs convey immobility information (Blanchard C, Roll R, Roll JP, Kavounoudias A. PLoS One 8: e62475, 2013). Here, we investigated whether visuotactile integration can optimize velocity discrimination of illusory hand movements in line with Bayesian predictions. We induced illusory movements in 15 volunteers by visual and/or tactile stimulation delivered at six angular velocities. Participants had to compare hand illusion velocities with a 5°/s hand reference movement in an alternative forced choice paradigm. Results showed that the discrimination threshold decreased in the visuotactile condition compared with unimodal (visual or tactile) conditions, reflecting better bimodal discrimination. The perceptual strength (gain) of the illusions also increased: the stimulation required to give rise to a 5°/s illusory movement was slower in the visuotactile condition compared with each of the two unimodal conditions. The maximum likelihood estimation model satisfactorily predicted the improved discrimination threshold but not the increase in gain. When we added a zero-centered prior, reflecting immobility information, the Bayesian model did actually predict the gain increase but systematically overestimated it. Interestingly, the predicted gains better fit the visuotactile performances when a proprioceptive noise was generated by covibrating antagonist wrist muscles. These findings show that kinesthetic information of visual and tactile origins is optimally integrated to improve velocity discrimination of self-hand movements. However, a Bayesian model alone could not fully describe the illusory phenomenon pointing to the crucial importance of the omnipresent muscle proprioceptive cues with respect to other sensory cues for kinesthesia. Copyright © 2016 the American Physiological Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Illusory hand movements can be elicited by a textured disk or a visual pattern rotating under one's hand, while proprioceptive inputs convey immobility information (Blanchard C, Roll R, Roll JP, Kavounoudias A. PLoS One 8: e62475, 2013). Here, we investigated whether visuotactile integration can optimize velocity discrimination of illusory hand movements in line with Bayesian predictions. We induced illusory movements in 15 volunteers by visual and/or tactile stimulation delivered at six angular velocities. Participants had to compare hand illusion velocities with a 5°/s hand reference movement in an alternative forced choice paradigm. Results showed that the discrimination threshold decreased in the visuotactile condition compared with unimodal (visual or tactile) conditions, reflecting better bimodal discrimination. The perceptual strength (gain) of the illusions also increased: the stimulation required to give rise to a 5°/s illusory movement was slower in the visuotactile condition compared with each of the two unimodal conditions. The maximum likelihood estimation model satisfactorily predicted the improved discrimination threshold but not the increase in gain. When we added a zero-centered prior, reflecting immobility information, the Bayesian model did actually predict the gain increase but systematically overestimated it. Interestingly, the predicted gains better fit the visuotactile performances when a proprioceptive noise was generated by covibrating antagonist wrist muscles. These findings show that kinesthetic information of visual and tactile origins is optimally integrated to improve velocity discrimination of self-hand movements. However, a Bayesian model alone could not fully describe the illusory phenomenon pointing to the crucial importance of the omnipresent muscle proprioceptive cues with respect to other sensory cues for kinesthesia. Copyright © 2016 the American Physiological Society |
Tighilet, B; Dutheil, S; Siponen, M I; Norena, A J Reactive neurogenesis and down-regulation of the potassiumchloride cotransporter KCC2 in the cochlear nuclei after cochlear deafferentation Article de journal Frontiers in Parmacology, 2016. @article{Tighilet2016, title = {Reactive neurogenesis and down-regulation of the potassiumchloride cotransporter KCC2 in the cochlear nuclei after cochlear deafferentation}, author = {B. Tighilet and S. Dutheil and M. I. Siponen and A. J. Norena}, doi = {10.3389/fphar.2016.00281}, year = {2016}, date = {2016-08-31}, journal = {Frontiers in Parmacology}, abstract = {While many studies have been devoted to investigating the homeostatic plasticity triggered by cochlear hearing loss, the cellular and molecular mechanisms involved in these central changes remain elusive. In the present study, we investigated the possibility of reactive neurogenesis after unilateral cochlear nerve section in the cochlear nucleus (CN) of cats. We found a strong cell proliferation in all the CN sub-divisions ipsilateral to the lesion. Most of the newly generated cells survive up to 1 month after cochlear deafferentation in all cochlear nuclei (except the dorsal CN) and give rise to a variety of cell types, i.e., microglial cells, astrocytes, and neurons. Interestingly, many of the newborn neurons had an inhibitory (GABAergic) phenotype. This result is intriguing since sensory deafferentation is usually accompanied by enhanced excitation, consistent with a reduction in central inhibition. The membrane potential effect of GABA depends, however, on the intra-cellular chloride concentration, which is maintained at low levels in adults by the potassium chloride co-transporter KCC2. The KCC2 density on the plasma membrane of neurons was then assessed after cochlear deafferentation in the cochlear nuclei ipsilateral and contralateral to the lesion. Cochlear deafferentation is accompanied by a strong down-regulation of KCC2 ipsilateral to the lesion at 3 and 30 days post-lesion. This study suggests that reactive neurogenesis and down-regulation of KCC2 is part of the vast repertoire involved in homeostatic plasticity triggered by hearing loss. These central changes may also play a role in the generation of tinnitus and hyperacusis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } While many studies have been devoted to investigating the homeostatic plasticity triggered by cochlear hearing loss, the cellular and molecular mechanisms involved in these central changes remain elusive. In the present study, we investigated the possibility of reactive neurogenesis after unilateral cochlear nerve section in the cochlear nucleus (CN) of cats. We found a strong cell proliferation in all the CN sub-divisions ipsilateral to the lesion. Most of the newly generated cells survive up to 1 month after cochlear deafferentation in all cochlear nuclei (except the dorsal CN) and give rise to a variety of cell types, i.e., microglial cells, astrocytes, and neurons. Interestingly, many of the newborn neurons had an inhibitory (GABAergic) phenotype. This result is intriguing since sensory deafferentation is usually accompanied by enhanced excitation, consistent with a reduction in central inhibition. The membrane potential effect of GABA depends, however, on the intra-cellular chloride concentration, which is maintained at low levels in adults by the potassium chloride co-transporter KCC2. The KCC2 density on the plasma membrane of neurons was then assessed after cochlear deafferentation in the cochlear nuclei ipsilateral and contralateral to the lesion. Cochlear deafferentation is accompanied by a strong down-regulation of KCC2 ipsilateral to the lesion at 3 and 30 days post-lesion. This study suggests that reactive neurogenesis and down-regulation of KCC2 is part of the vast repertoire involved in homeostatic plasticity triggered by hearing loss. These central changes may also play a role in the generation of tinnitus and hyperacusis. |
Borel, L; Ribot-Ciscar, E Improving postural control by applying mechanical noise to ankle muscle tendons Article de journal Experimental Brain Research, 234 (8), p. 2305-2314, 2016. @article{Borel2016, title = {Improving postural control by applying mechanical noise to ankle muscle tendons}, author = {L. Borel and E. Ribot-Ciscar}, doi = {10.1007/s00221-016-4636-2}, year = {2016}, date = {2016-08-01}, journal = {Experimental Brain Research}, volume = {234}, number = {8}, pages = {2305-2314}, abstract = {The application of subthreshold mechanical vibrations with random frequencies (white mechanical noise) to ankle muscle tendons is known to increase muscle proprioceptive information and to improve the detection of ankle movements. The aim of the present study was to analyze the effect of this mechanical noise on postural control, its possible modulation according to the sensory strategies used for postural control, and the consequences of increasing postural difficulty. The upright stance of 20 healthy young participants tested with their eyes closed was analyzed during the application of four different levels of noise and compared to that in the absence of noise (control) in three conditions: static, static on foam, and dynamic (sinusoidal translation). The quiet standing condition was conducted with the eyes open and closed to determine the subjects’ visual dependency to maintain postural stability. Postural performance was assessed using posturographic and motion analysis evaluations. The results in the static condition showed that the spectral power density of body sway significantly decreased with an optimal level of noise and that the higher the spectral power density without noise, the greater the noise effect, irrespective of visual dependency. Finally, noise application was ineffective in the foam and dynamic conditions. We conclude that the application of mechanical noise to ankle muscle tendons is a means to improve quiet standing only. These results suggest that mechanical noise stimulation may be more effective in more impaired populations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The application of subthreshold mechanical vibrations with random frequencies (white mechanical noise) to ankle muscle tendons is known to increase muscle proprioceptive information and to improve the detection of ankle movements. The aim of the present study was to analyze the effect of this mechanical noise on postural control, its possible modulation according to the sensory strategies used for postural control, and the consequences of increasing postural difficulty. The upright stance of 20 healthy young participants tested with their eyes closed was analyzed during the application of four different levels of noise and compared to that in the absence of noise (control) in three conditions: static, static on foam, and dynamic (sinusoidal translation). The quiet standing condition was conducted with the eyes open and closed to determine the subjects’ visual dependency to maintain postural stability. Postural performance was assessed using posturographic and motion analysis evaluations. The results in the static condition showed that the spectral power density of body sway significantly decreased with an optimal level of noise and that the higher the spectral power density without noise, the greater the noise effect, irrespective of visual dependency. Finally, noise application was ineffective in the foam and dynamic conditions. We conclude that the application of mechanical noise to ankle muscle tendons is a means to improve quiet standing only. These results suggest that mechanical noise stimulation may be more effective in more impaired populations. |
Sanchez Panchuelo RM Ackerley R, Glover PM Bowtell RW Wessberg Francis ST McGlone J F Mapping quantal touch using 7 Tesla functional magnetic resonance imaging and single-unit intraneural microstimulation Article de journal eLife, 5 , p. e12812, 2016. @article{RM*2016, title = {Mapping quantal touch using 7 Tesla functional magnetic resonance imaging and single-unit intraneural microstimulation}, author = {Sanchez Panchuelo RM, Ackerley R, Glover PM, Bowtell RW, Wessberg J, Francis ST, McGlone F }, url = {https://elifesciences.org/content/5/e12812}, doi = {10.7554/eLife.12812}, year = {2016}, date = {2016-07-30}, journal = {eLife}, volume = {5}, pages = {e12812}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Ackerley R Borich M, Oddo Ionta C S Insights and perspectives on sensory-motor integration and rehabilitation Article de journal Multisensory Research, March , p. 1-27, 2016, ISSN: 2213-4794. @article{R2016, title = {Insights and perspectives on sensory-motor integration and rehabilitation}, author = {Ackerley R, Borich M, Oddo C, Ionta S }, url = {http://booksandjournals.brillonline.com/content/journals/10.1163/22134808-00002530}, doi = {10.1163/22134808-00002530}, issn = {2213-4794}, year = {2016}, date = {2016-07-01}, journal = {Multisensory Research}, volume = {March}, pages = {1-27}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Gaboyard-Niay, S; Travo, C; Saleur, A; Broussy, A; Brugeaud, A; Chabbert, C Correlation between synaptic rearrangements and behavioral deficits after local excitotoxic insult in the mammal vestibule: an animal model of vertigo symptoms? Article de journal Disease Models & Mechanisms, 2016. @article{Gaboyard-Niay2016, title = {Correlation between synaptic rearrangements and behavioral deficits after local excitotoxic insult in the mammal vestibule: an animal model of vertigo symptoms?}, author = {S. Gaboyard-Niay and C. Travo and A. Saleur and A. Broussy and A. Brugeaud and C. Chabbert}, doi = {http://dx.doi.org/10.1242/dmm.024521}, year = {2016}, date = {2016-06-29}, journal = {Disease Models & Mechanisms}, abstract = {Damage to inner ear afferent terminals is believed to result in many auditory and vestibular dysfunctions. The sequence of afferent injuries and repair, as well as their correlation with vertigo symptoms remains poorly documented. In particular, information on the changes that take place at the primary vestibular endings during the first hours following a selective insult is lacking. In the present study we combined histological analysis with behavioral assessments of vestibular function in a rat model of unilateral vestibular excitotoxic insult. Excitotoxicity resulted in an immediate but transient alteration of the balance function that was resolved within a week. Concomitantly, vestibular primary afferents underwent a sequence of structural changes followed by spontaneous repair. Within the first two hours after the insult, a first phase of pronounced vestibular dysfunction coincided with extensive swelling of afferent terminals. In the next 24 hours, a second phase of significant but incomplete reduction of the vestibular dysfunction was accompanied by a resorption of swollen terminals and fiber retraction. Eventually, within one week, a third phase of complete balance restoration occurred. The slow and progressive withdrawal of the balance dysfunction correlated with full reconstitution of nerve terminals. Competitive re-innervation by afferent and efferent terminals that mimicked developmental synaptogenesis resulted in full re-afferentation of the sensory epithelia. By deciphering the sequence of structural alterations that occur in the vestibule during selective excitotoxic impairment, this study offers new understandings on how a vestibular insult develops in the vestibule and how it governs the heterogeneity of vertigo symptoms. Received January 6, 2016. Accepted June 21, 2016. © 2016. Published by The Company of Biologists Ltd This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Damage to inner ear afferent terminals is believed to result in many auditory and vestibular dysfunctions. The sequence of afferent injuries and repair, as well as their correlation with vertigo symptoms remains poorly documented. In particular, information on the changes that take place at the primary vestibular endings during the first hours following a selective insult is lacking. In the present study we combined histological analysis with behavioral assessments of vestibular function in a rat model of unilateral vestibular excitotoxic insult. Excitotoxicity resulted in an immediate but transient alteration of the balance function that was resolved within a week. Concomitantly, vestibular primary afferents underwent a sequence of structural changes followed by spontaneous repair. Within the first two hours after the insult, a first phase of pronounced vestibular dysfunction coincided with extensive swelling of afferent terminals. In the next 24 hours, a second phase of significant but incomplete reduction of the vestibular dysfunction was accompanied by a resorption of swollen terminals and fiber retraction. Eventually, within one week, a third phase of complete balance restoration occurred. The slow and progressive withdrawal of the balance dysfunction correlated with full reconstitution of nerve terminals. Competitive re-innervation by afferent and efferent terminals that mimicked developmental synaptogenesis resulted in full re-afferentation of the sensory epithelia. By deciphering the sequence of structural alterations that occur in the vestibule during selective excitotoxic impairment, this study offers new understandings on how a vestibular insult develops in the vestibule and how it governs the heterogeneity of vertigo symptoms. Received January 6, 2016. Accepted June 21, 2016. © 2016. Published by The Company of Biologists Ltd This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed. |
Diéguez, S; Lopez, C The bodily self: Insights from clinical and experimental research Article de journal Annals of Physical and Rehabilitation Medicine, 2016. @article{Dieguez2016, title = {The bodily self: Insights from clinical and experimental research}, author = {S. Diéguez and C. Lopez}, doi = {10.1016/j.rehab.2016.04.007}, year = {2016}, date = {2016-06-16}, journal = {Annals of Physical and Rehabilitation Medicine}, abstract = {This review article summarizes neuropsychological descriptions of abnormal body representations in brain-damaged patients and recent neuroscientific investigations of their sensorimotor underpinnings in healthy participants. The first part of the article describes unilateral disorders of the bodily self, such as asomatognosia, feelings of amputation, supernumerary phantom limbs and somatoparaphrenia, as well as descriptions of non-lateralized disorders of the bodily self, including Alice in Wonderland syndrome and autoscopic hallucinations. Because the sensorimotor mechanisms of these disorders are unclear, we focus on clinical descriptions and insist on the importance of reporting clinical cases to better understand the full range of bodily disorders encountered in neurological diseases. The second part of the article presents the advantages of merging neuroscientific approaches of the bodily self with immersive virtual reality, robotics and neuroprosthetics to foster the understanding of the multisensory, motor and neural mechanisms of bodily representations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This review article summarizes neuropsychological descriptions of abnormal body representations in brain-damaged patients and recent neuroscientific investigations of their sensorimotor underpinnings in healthy participants. The first part of the article describes unilateral disorders of the bodily self, such as asomatognosia, feelings of amputation, supernumerary phantom limbs and somatoparaphrenia, as well as descriptions of non-lateralized disorders of the bodily self, including Alice in Wonderland syndrome and autoscopic hallucinations. Because the sensorimotor mechanisms of these disorders are unclear, we focus on clinical descriptions and insist on the importance of reporting clinical cases to better understand the full range of bodily disorders encountered in neurological diseases. The second part of the article presents the advantages of merging neuroscientific approaches of the bodily self with immersive virtual reality, robotics and neuroprosthetics to foster the understanding of the multisensory, motor and neural mechanisms of bodily representations. |
Aimonetti, J-M; Ribot-Ciscar, E Pain management in photoepilation Article de journal Journal of Cosmetic Dermatology, 15 (2), p. 194-199, 2016. @article{Aimonetti2016, title = {Pain management in photoepilation}, author = {J-M. Aimonetti and E. Ribot-Ciscar}, doi = {10.1111/jocd.12196}, year = {2016}, date = {2016-06-14}, journal = {Journal of Cosmetic Dermatology}, volume = {15}, number = {2}, pages = {194-199}, abstract = {The hair follicle is a complex, hormonally active structure with permanent and cyclically renewed parts which are highly innervated by myelinated and unmyelinated afferent fibers. Hair removal, a very ancient practice, affects this sensory network and causes both acute and diffuse pain associated with inflammatory reaction. Optic permanent hair removal is becoming a popular alternative to traditional methods such as shaving, waxing, among other methods. These optical removal devices thermally destroy the target chromophore, that is, melanin, without damaging the surrounding skin. The increase in the skin surface temperature causes mild-to-severe pain, and optical hair removal has to be combined with pain relieving devices. Pain management relies on topical anesthetic agents, cooling devices, or non-noxious cutaneous stimulation whose mechanisms of action and efficiency are discussed in this article. © 2015 Wiley Periodicals, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The hair follicle is a complex, hormonally active structure with permanent and cyclically renewed parts which are highly innervated by myelinated and unmyelinated afferent fibers. Hair removal, a very ancient practice, affects this sensory network and causes both acute and diffuse pain associated with inflammatory reaction. Optic permanent hair removal is becoming a popular alternative to traditional methods such as shaving, waxing, among other methods. These optical removal devices thermally destroy the target chromophore, that is, melanin, without damaging the surrounding skin. The increase in the skin surface temperature causes mild-to-severe pain, and optical hair removal has to be combined with pain relieving devices. Pain management relies on topical anesthetic agents, cooling devices, or non-noxious cutaneous stimulation whose mechanisms of action and efficiency are discussed in this article. © 2015 Wiley Periodicals, Inc. |
Touzet, Claude Morvan’s syndrome and the sustained absence of all sleep rhythms for months or years: an hypothesis Article de journal Med. Hypotheses, 94 , p. 51-54, 2016. @article{Touzet2016, title = {Morvan’s syndrome and the sustained absence of all sleep rhythms for months or years: an hypothesis}, author = {Claude Touzet}, editor = {Elsevier}, url = {http://www.touzet.org/Claude/Web-Fac-Claude/Publi/Medical-Hypotheses/Morvan_Syndrome_TOUZET.pdf}, doi = {http://dx.doi.org/10.1016/j.mehy.2016.06.011}, year = {2016}, date = {2016-06-09}, journal = {Med. Hypotheses}, volume = {94}, pages = {51-54}, abstract = {Despite the predation costs, sleep is ubiquitous in the animal realm. Humans spend a third of their life sleeping, and the quality of sleep has been related to co-morbidity, Alzheimer disease, etc. Excessive wakefulness induces rapid changes in cognitive performances, and it is claimed that one could die of sleep deprivation as quickly as by absence of water. In this context, the fact that a few people are able to go without sleep for months, even years, without displaying any cognitive troubles requires explanations. Theories ascribing sleep to memory consolidation are unable to explain such observations. It is not the case of the theory of sleep as the hebbian reinforcement of the inhibitory synapses (ToS-HRIS). Hebbian learning (Long Term Depression – LTD) guarantees that an efficient inhibitory synapse will lose its efficiency just because it is efficient at avoiding the activation of the post-synaptic neuron. This erosion of the inhibition is replenished by hebbian learning (Long Term Potentiation – LTP) when pre and postsynaptic neurons are active together – which is exactly what happens with the travelling depolarization waves of the slow-wave sleep (SWS). The best documented cases of months-long insomnia are reports of patients with Morvan’s syndrome. This syndrome has an autoimmune cause that impedes – among many things – the potassium channels of the post-synaptic neurons, increasing LTP and decreasing LTD. We hypothesize that the absence of inhibitory efficiency erosion during wakefulness (thanks to a decrease of inhibitory LTD) is the cause for an absence of slow-wave sleep (SWS), which results also in the absence of REM sleep.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Despite the predation costs, sleep is ubiquitous in the animal realm. Humans spend a third of their life sleeping, and the quality of sleep has been related to co-morbidity, Alzheimer disease, etc. Excessive wakefulness induces rapid changes in cognitive performances, and it is claimed that one could die of sleep deprivation as quickly as by absence of water. In this context, the fact that a few people are able to go without sleep for months, even years, without displaying any cognitive troubles requires explanations. Theories ascribing sleep to memory consolidation are unable to explain such observations. It is not the case of the theory of sleep as the hebbian reinforcement of the inhibitory synapses (ToS-HRIS). Hebbian learning (Long Term Depression – LTD) guarantees that an efficient inhibitory synapse will lose its efficiency just because it is efficient at avoiding the activation of the post-synaptic neuron. This erosion of the inhibition is replenished by hebbian learning (Long Term Potentiation – LTP) when pre and postsynaptic neurons are active together – which is exactly what happens with the travelling depolarization waves of the slow-wave sleep (SWS). The best documented cases of months-long insomnia are reports of patients with Morvan’s syndrome. This syndrome has an autoimmune cause that impedes – among many things – the potassium channels of the post-synaptic neurons, increasing LTP and decreasing LTD. We hypothesize that the absence of inhibitory efficiency erosion during wakefulness (thanks to a decrease of inhibitory LTD) is the cause for an absence of slow-wave sleep (SWS), which results also in the absence of REM sleep. |
Dutheil, S; Watabe, I; Sadlaoud, K; Tonetto, A; Tighilet, B Journal of Neuroscience, 2016. @article{Dutheil2016, title = {BDNF signaling promotes vestibular compensation by increasing neurogenesis and remodeling the expression of potassium-chloride cotransporter KCC2 and GABAa receptor in the vestibular nuclei}, author = {S. Dutheil and I. Watabe and K. Sadlaoud and A. Tonetto and B. Tighilet}, doi = {10.1523/JNEUROSCI.0945-16.2016}, year = {2016}, date = {2016-06-08}, journal = {Journal of Neuroscience}, abstract = {Reactive cell proliferation occurs rapidly in the cat vestibular nuclei (VN) after unilateral vestibular neurectomy (UVN) and has been reported to facilitate the recovery of posturo-locomotor functions. Interestingly, whereas animals experience impairments for several weeks, extraordinary plasticity mechanisms take place in the local microenvironment of the VN: newborn cells survive and acquire different phenotypes, such as microglia, astrocytes, or GABAergic neurons, whereas animals eventually recover completely from their lesion-induced deficits. Because brain-derived neurotrophic factor (BDNF) can modulate vestibular functional recovery and neurogenesis in mammals, in this study, we examined the effect of BDNF chronic intracerebroventricular infusion versus K252a (a Trk receptor antagonist) in our UVN model. Results showed that long-term intracerebroventricular infusion of BDNF accelerated the restoration of vestibular functions and significantly increased UVN-induced neurogenesis, whereas K252a blocked that effect and drastically delayed and prevented the complete restoration of vestibular functions. Further, because the level of excitability in the deafferented VN is correlated with behavioral recovery, we examined the state of neuronal excitability using two specific markers: the cation-chloride cotransporter KCC2 (which determines the hyperpolarizing action of GABA) and GABAA receptors. We report for the first time that, during an early time window after UVN, significant BDNF-dependent remodeling of excitability markers occurs in the brainstem. These data suggest that GABA acquires a transient depolarizing action during recovery from UVN, which potentiates the observed reactive neurogenesis and accelerates vestibular functional recovery. These findings suggest that BDNF and/or KCC2 could represent novel treatment strategies for vestibular pathologies. SIGNIFICANCE STATEMENT In this study, we report for the first time that brain-derived neurotrophic factor potentiates vestibular neurogenesis and significantly accelerates functional recovery after unilateral vestibular injury. We also show that specific markers of excitability, the potassium-chloride cotransporter KCC2 and GABAA receptors, undergo remarkable fluctuations within vestibular nuclei (VN), strongly suggesting that GABA acquires a transient depolarizing action in the VN during the recovery period. This novel plasticity mechanism could explain in part how the system returns to electrophysiological homeostasis between the deafferented and intact VN, considered in the literature to be a key parameter of vestibular compensation. In this context, our results open new perspectives for the development of therapeutic approaches to alleviate the vestibular symptoms and favor vestibular function recovery. Received March 22, 2016. Revision received April 29, 2016. Accepted May 2, 2016. Copyright © 2016 the authors 0270-6474/16/366200-14$15.00/0}, keywords = {}, pubstate = {published}, tppubtype = {article} } Reactive cell proliferation occurs rapidly in the cat vestibular nuclei (VN) after unilateral vestibular neurectomy (UVN) and has been reported to facilitate the recovery of posturo-locomotor functions. Interestingly, whereas animals experience impairments for several weeks, extraordinary plasticity mechanisms take place in the local microenvironment of the VN: newborn cells survive and acquire different phenotypes, such as microglia, astrocytes, or GABAergic neurons, whereas animals eventually recover completely from their lesion-induced deficits. Because brain-derived neurotrophic factor (BDNF) can modulate vestibular functional recovery and neurogenesis in mammals, in this study, we examined the effect of BDNF chronic intracerebroventricular infusion versus K252a (a Trk receptor antagonist) in our UVN model. Results showed that long-term intracerebroventricular infusion of BDNF accelerated the restoration of vestibular functions and significantly increased UVN-induced neurogenesis, whereas K252a blocked that effect and drastically delayed and prevented the complete restoration of vestibular functions. Further, because the level of excitability in the deafferented VN is correlated with behavioral recovery, we examined the state of neuronal excitability using two specific markers: the cation-chloride cotransporter KCC2 (which determines the hyperpolarizing action of GABA) and GABAA receptors. We report for the first time that, during an early time window after UVN, significant BDNF-dependent remodeling of excitability markers occurs in the brainstem. These data suggest that GABA acquires a transient depolarizing action during recovery from UVN, which potentiates the observed reactive neurogenesis and accelerates vestibular functional recovery. These findings suggest that BDNF and/or KCC2 could represent novel treatment strategies for vestibular pathologies. SIGNIFICANCE STATEMENT In this study, we report for the first time that brain-derived neurotrophic factor potentiates vestibular neurogenesis and significantly accelerates functional recovery after unilateral vestibular injury. We also show that specific markers of excitability, the potassium-chloride cotransporter KCC2 and GABAA receptors, undergo remarkable fluctuations within vestibular nuclei (VN), strongly suggesting that GABA acquires a transient depolarizing action in the VN during the recovery period. This novel plasticity mechanism could explain in part how the system returns to electrophysiological homeostasis between the deafferented and intact VN, considered in the literature to be a key parameter of vestibular compensation. In this context, our results open new perspectives for the development of therapeutic approaches to alleviate the vestibular symptoms and favor vestibular function recovery. Received March 22, 2016. Revision received April 29, 2016. Accepted May 2, 2016. Copyright © 2016 the authors 0270-6474/16/366200-14$15.00/0 |
Hall, D A; Haider, H; Szczepek, A J; Lau, P; Rabatt, S; Jones-Duette, J; Londero, A; Edvall, N K; Cederroth, C R; Mielczarek, M; Fuller, T; Batuecas-Caletrio, A; Brueggemen, P; Thompson, D M; Norena, A; Cima, R F F; Mehta, R L; Mazurek, B Systematic review of outcome domains and instruments used in clinical trials of tinnitus treatments in adults Article de journal Trials, 2016. @article{Hall2016, title = {Systematic review of outcome domains and instruments used in clinical trials of tinnitus treatments in adults}, author = {D. A. Hall and H. Haider and A. J. Szczepek and P. Lau and S. Rabatt and J. Jones-Duette and A. Londero and N. K. Edvall and C. R. Cederroth and M. Mielczarek and T. Fuller and A. Batuecas-Caletrio and P. Brueggemen and D. M. Thompson and A. Norena and R. F. F. Cima and R. L. Mehta and B. Mazurek}, doi = {10.1186/s13063-016-1399-9}, year = {2016}, date = {2016-06-01}, journal = {Trials}, abstract = {Background There is no evidence-based guidance to facilitate design decisions for confirmatory trials or systematic reviews investigating treatment efficacy for adults with tinnitus. This systematic review therefore seeks to ascertain the current status of trial designs by identifying and evaluating the reporting of outcome domains and instruments in the treatment of adults with tinnitus. Methods Records were identified by searching PubMed, EMBASE CINAHL, EBSCO, and CENTRAL clinical trial registries (ClinicalTrials.gov, ISRCTN, ICTRP) and the Cochrane Database of Systematic Reviews. Eligible records were those published from 1 July 2006 to 12 March 2015. Included studies were those reporting adults aged 18 years or older who reported tinnitus as a primary complaint, and who were enrolled into a randomised controlled trial, a before and after study, a non-randomised controlled trial, a case-controlled study or a cohort study, and written in English. Studies with fewer than 20 participants were excluded. Results Two hundred and twenty-eight studies were included. Thirty-five different primary outcome domains were identified spanning seven categories (tinnitus percept, impact of tinnitus, co-occurring complaints, quality of life, body structures and function, treatment-related outcomes and unclear or not specified). Over half the studies (55 %) did not clearly define the complaint of interest. Tinnitus loudness was the domain most often reported (14 %), followed by tinnitus distress (7 %). Seventy-eight different primary outcome instruments were identified. Instruments assessing multiple attributes of the impact of tinnitus were most common (34 %). Overall, 24 different patient-reported tools were used, predominantly the Tinnitus Handicap Inventory (15 %). Loudness was measured in diverse ways including a numerical rating scale (8 %), loudness matching (4 %), minimum masking level (1 %) and loudness discomfort level (1 %). Ten percent of studies did not clearly report the instrument used. Conclusions Our findings indicate poor appreciation of the basic principles of good trial design, particularly the importance of specifying what aspect of therapeutic benefit is the main outcome. No single outcome was reported in all studies and there was a broad diversity of outcome instruments. PROSPERO registration The systematic review protocol is registered on PROSPERO (International Prospective Register of Systematic Reviews): CRD42015017525. Registered on 12 March 2015 revised on 15 March 2016.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Background There is no evidence-based guidance to facilitate design decisions for confirmatory trials or systematic reviews investigating treatment efficacy for adults with tinnitus. This systematic review therefore seeks to ascertain the current status of trial designs by identifying and evaluating the reporting of outcome domains and instruments in the treatment of adults with tinnitus. Methods Records were identified by searching PubMed, EMBASE CINAHL, EBSCO, and CENTRAL clinical trial registries (ClinicalTrials.gov, ISRCTN, ICTRP) and the Cochrane Database of Systematic Reviews. Eligible records were those published from 1 July 2006 to 12 March 2015. Included studies were those reporting adults aged 18 years or older who reported tinnitus as a primary complaint, and who were enrolled into a randomised controlled trial, a before and after study, a non-randomised controlled trial, a case-controlled study or a cohort study, and written in English. Studies with fewer than 20 participants were excluded. Results Two hundred and twenty-eight studies were included. Thirty-five different primary outcome domains were identified spanning seven categories (tinnitus percept, impact of tinnitus, co-occurring complaints, quality of life, body structures and function, treatment-related outcomes and unclear or not specified). Over half the studies (55 %) did not clearly define the complaint of interest. Tinnitus loudness was the domain most often reported (14 %), followed by tinnitus distress (7 %). Seventy-eight different primary outcome instruments were identified. Instruments assessing multiple attributes of the impact of tinnitus were most common (34 %). Overall, 24 different patient-reported tools were used, predominantly the Tinnitus Handicap Inventory (15 %). Loudness was measured in diverse ways including a numerical rating scale (8 %), loudness matching (4 %), minimum masking level (1 %) and loudness discomfort level (1 %). Ten percent of studies did not clearly report the instrument used. Conclusions Our findings indicate poor appreciation of the basic principles of good trial design, particularly the importance of specifying what aspect of therapeutic benefit is the main outcome. No single outcome was reported in all studies and there was a broad diversity of outcome instruments. PROSPERO registration The systematic review protocol is registered on PROSPERO (International Prospective Register of Systematic Reviews): CRD42015017525. Registered on 12 March 2015 revised on 15 March 2016. |
Zennou-Azogui, Y; Catz, N; Xerri, C Hypergravity within a critical period impacts on the maturation of somatosensory cortical maps and their potential for use-dependent plasticity in the adult Article de journal Journal of Neurophysiology, 2016. @article{Zennou-Azogui2016, title = {Hypergravity within a critical period impacts on the maturation of somatosensory cortical maps and their potential for use-dependent plasticity in the adult}, author = {Y. Zennou-Azogui and N. Catz and C. Xerri}, doi = {10.1152/jn.00900.2015}, year = {2016}, date = {2016-06-01}, journal = {Journal of Neurophysiology}, abstract = {We investigated experience-dependent plasticity of somatosensory maps in rat S1 cortex during early development. We analyzed both short- and long-term effects of exposure to 2G hypergravity (HG) during the first 3 postnatal weeks on forepaw representations. We also examined the potential of adult somatosensory maps for experience-dependent plasticity after early HG rearing. At postnatal day 22, HG was found to induce an enlargement of cortical zones driven by nail displacements and a contraction of skin sectors of the forepaw map. In these remaining zones serving the skin, neurons displayed expanded glabrous skin receptive fields (RFs). HG also induced a bias in the directional sensitivity of neuronal responses to nail displacement. HG-induced map changes were still found after 16 wk of housing in normogravity (NG). However, the glabrous skin RFs recorded in HG rats decreased to values similar to that of NG rats, as early as the end of the first week of housing in NG. Moreover, the expansion of the glabrous skin area and decrease in RF size normally induced in adults by an enriched environment (EE) did not occur in the HG rats, even after 16 wk of EE housing in NG. Our findings reveal that early postnatal experience critically and durably shapes S1 forepaw maps and limits their potential to be modified by novel experience in adulthood. Copyright © 2016 the American Physiological Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We investigated experience-dependent plasticity of somatosensory maps in rat S1 cortex during early development. We analyzed both short- and long-term effects of exposure to 2G hypergravity (HG) during the first 3 postnatal weeks on forepaw representations. We also examined the potential of adult somatosensory maps for experience-dependent plasticity after early HG rearing. At postnatal day 22, HG was found to induce an enlargement of cortical zones driven by nail displacements and a contraction of skin sectors of the forepaw map. In these remaining zones serving the skin, neurons displayed expanded glabrous skin receptive fields (RFs). HG also induced a bias in the directional sensitivity of neuronal responses to nail displacement. HG-induced map changes were still found after 16 wk of housing in normogravity (NG). However, the glabrous skin RFs recorded in HG rats decreased to values similar to that of NG rats, as early as the end of the first week of housing in NG. Moreover, the expansion of the glabrous skin area and decrease in RF size normally induced in adults by an enriched environment (EE) did not occur in the HG rats, even after 16 wk of EE housing in NG. Our findings reveal that early postnatal experience critically and durably shapes S1 forepaw maps and limits their potential to be modified by novel experience in adulthood. Copyright © 2016 the American Physiological Society. |
Chancel, M; Brun, C; Kavounoudias, A; Guerraz, M The kinaesthetic mirror illusion: How much does the mirror matter? Article de journal Experimental Brain Research, 234 (6), p. 1459-1468, 2016. @article{Chancel2016b, title = {The kinaesthetic mirror illusion: How much does the mirror matter?}, author = {M. Chancel and C. Brun and A. Kavounoudias and M. Guerraz}, doi = {10.1007/s00221-015-4549-5}, year = {2016}, date = {2016-06-01}, journal = {Experimental Brain Research}, volume = {234}, number = {6}, pages = {1459-1468}, abstract = {The reflection of a moving hand in a mirror positioned in the sagittal plane can create an illusion of symmetrical, bimanual movement. This illusion is implicitly presumed to be of visual origin. However, muscle proprioceptive afferents of the arm reflected in the mirror might also affect the perceived position and movement of the other arm. We characterized the relative contributions of visual and proprioceptive cues by performing two experiments. In Experiment 1, we sought to establish whether kinaesthetic illusions induced using the mirror paradigm would survive marked visual impoverishment (obtained by covering between 0 and 100 % of the mirror in 16 % steps). We found that the mirror illusion was only significantly influenced when the visual degradation was 84 % or more. In Experiment 2, we masked the muscle proprioceptive afferents of the arm reflected in the mirror by co-vibrating antagonistic muscles. We found that masking the proprioceptive afferents reduced the velocity of the illusory displacement of the other arm. These results confirm that the mirror illusion is not a purely visual illusion but emerges from a combination of congruent signals from the two arms, i.e. visual afferents from the virtually moving arm and proprioceptive afferents from the contralateral, moving arm. }, keywords = {}, pubstate = {published}, tppubtype = {article} } The reflection of a moving hand in a mirror positioned in the sagittal plane can create an illusion of symmetrical, bimanual movement. This illusion is implicitly presumed to be of visual origin. However, muscle proprioceptive afferents of the arm reflected in the mirror might also affect the perceived position and movement of the other arm. We characterized the relative contributions of visual and proprioceptive cues by performing two experiments. In Experiment 1, we sought to establish whether kinaesthetic illusions induced using the mirror paradigm would survive marked visual impoverishment (obtained by covering between 0 and 100 % of the mirror in 16 % steps). We found that the mirror illusion was only significantly influenced when the visual degradation was 84 % or more. In Experiment 2, we masked the muscle proprioceptive afferents of the arm reflected in the mirror by co-vibrating antagonistic muscles. We found that masking the proprioceptive afferents reduced the velocity of the illusory displacement of the other arm. These results confirm that the mirror illusion is not a purely visual illusion but emerges from a combination of congruent signals from the two arms, i.e. visual afferents from the virtually moving arm and proprioceptive afferents from the contralateral, moving arm. |
Bringoux, L; Cesare, Scotto Di C; Borel, L; Macaluso, T; Sarlegna, F R Do Visual and Vestibular Inputs Compensate for Somatosensory Loss in the Perception of Spatial Orientation? Insights from a Deafferented Patient Article de journal Frontiers in Human Neuroscience, 10 , p. 181, 2016. @article{Bringoux2016, title = {Do Visual and Vestibular Inputs Compensate for Somatosensory Loss in the Perception of Spatial Orientation? Insights from a Deafferented Patient}, author = {L. Bringoux and C. Scotto Di Cesare and L. Borel and T. Macaluso and F. R. Sarlegna}, doi = {10.3389/fnhum.2016.00181}, year = {2016}, date = {2016-04-28}, journal = {Frontiers in Human Neuroscience}, volume = {10}, pages = {181}, abstract = {The present study aimed at investigating the consequences of a massive loss of somatosensory inputs on the perception of spatial orientation. The occurrence of possible compensatory processes for external (i.e., object) orientation perception and self-orientation perception was examined by manipulating visual and/or vestibular cues. To that aim, we compared perceptual responses of a deafferented patient (GL) with respect to age-matched Controls in two tasks involving gravity-related judgments. In the first task, subjects had to align a visual rod with the gravitational vertical (i.e., Subjective Visual Vertical: SVV) when facing a tilted visual frame in a classic Rod-and-Frame Test. In the second task, subjects had to report whether they felt tilted when facing different visuo-postural conditions which consisted in very slow pitch tilts of the body and/or visual surroundings away from vertical. Results showed that, much more than Controls, the deafferented patient was fully dependent on spatial cues issued from the visual frame when judging the SVV. On the other hand, the deafferented patient did not rely at all on visual cues for self-tilt detection. Moreover, the patient never reported any sensation of tilt up to 18° contrary to Controls, hence showing that she did not rely on vestibular (i.e., otoliths) signals for the detection of very slow body tilts either. Overall, this study demonstrates that a massive somatosensory deficit substantially impairs the perception of spatial orientation, and that the use of the remaining sensory inputs available to a deafferented patient differs regarding whether the judgment concerns external vs. self-orientation.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The present study aimed at investigating the consequences of a massive loss of somatosensory inputs on the perception of spatial orientation. The occurrence of possible compensatory processes for external (i.e., object) orientation perception and self-orientation perception was examined by manipulating visual and/or vestibular cues. To that aim, we compared perceptual responses of a deafferented patient (GL) with respect to age-matched Controls in two tasks involving gravity-related judgments. In the first task, subjects had to align a visual rod with the gravitational vertical (i.e., Subjective Visual Vertical: SVV) when facing a tilted visual frame in a classic Rod-and-Frame Test. In the second task, subjects had to report whether they felt tilted when facing different visuo-postural conditions which consisted in very slow pitch tilts of the body and/or visual surroundings away from vertical. Results showed that, much more than Controls, the deafferented patient was fully dependent on spatial cues issued from the visual frame when judging the SVV. On the other hand, the deafferented patient did not rely at all on visual cues for self-tilt detection. Moreover, the patient never reported any sensation of tilt up to 18° contrary to Controls, hence showing that she did not rely on vestibular (i.e., otoliths) signals for the detection of very slow body tilts either. Overall, this study demonstrates that a massive somatosensory deficit substantially impairs the perception of spatial orientation, and that the use of the remaining sensory inputs available to a deafferented patient differs regarding whether the judgment concerns external vs. self-orientation. |
Abboud, N; Fontbonne, A; Watabe, I; Tonetto, A; Brezun, J-M; Feron, F; Zine, A Culture conditions impact the maturation of traceable, transplantable mouse embryonic stem cell-derived otic progenitor cells Article de journal Journal of Tissue Engineering and Regenerative Medicine, 2016. @article{Abboud2016, title = {Culture conditions impact the maturation of traceable, transplantable mouse embryonic stem cell-derived otic progenitor cells}, author = {N. Abboud and A. Fontbonne and I. Watabe and A. Tonetto and J-M. Brezun and F. Feron and A. Zine}, doi = {10.1002/term.2163}, year = {2016}, date = {2016-04-21}, journal = {Journal of Tissue Engineering and Regenerative Medicine}, abstract = {The generation of replacement inner ear hair cells (HCs) remains a challenge and stem cell therapy holds the potential for developing therapeutic solutions to hearing and balance disorders. Recent developments have made significant strides in producing mouse otic progenitors using cell culture techniques to initiate HC differentiation. However, no consensus has been reached as to efficiency and therefore current methods remain unsatisfactory. In order to address these issues, we compare the generation of otic and HC progenitors from embryonic stem (ES) cells in two cell culture systems: suspension vs. adherent conditions. In the present study, an ES cell line derived from an Atoh1-green fluorescent protein (GFP) transgenic mouse was used to track the generation of otic progenitors, initial HCs and to compare these two differentiation systems. We used a two-step short-term differentiation method involving an induction period of 5 days during which ES cells were cultured in the presence of Wnt/transforming growth factor TGF-β inhibitors and insulin-like growth factor IGF-1 to suppress mesoderm and reinforce presumptive ectoderm and otic lineages. The generated embryoid bodies were then differentiated in medium containing basic fibroblast growth factor (bFGF) for an additional 5 days using either suspension or adherent culture methods. Upon completion of differentiation, quantitative polymerase chain reaction analysis and immunostaining monitored the expression of otic/HC progenitor lineage markers. The results indicate that cells differentiated in suspension cultures produced cells expressing otic progenitor/HC markers at a higher efficiency compared with the production of these cell types within adherent cultures. Furthermore, we demonstrated that a fraction of these cells can incorporate into ototoxin-injured mouse postnatal cochlea explants and express MYO7A after transplantation. Copyright © 2016 John Wiley & Sons, Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The generation of replacement inner ear hair cells (HCs) remains a challenge and stem cell therapy holds the potential for developing therapeutic solutions to hearing and balance disorders. Recent developments have made significant strides in producing mouse otic progenitors using cell culture techniques to initiate HC differentiation. However, no consensus has been reached as to efficiency and therefore current methods remain unsatisfactory. In order to address these issues, we compare the generation of otic and HC progenitors from embryonic stem (ES) cells in two cell culture systems: suspension vs. adherent conditions. In the present study, an ES cell line derived from an Atoh1-green fluorescent protein (GFP) transgenic mouse was used to track the generation of otic progenitors, initial HCs and to compare these two differentiation systems. We used a two-step short-term differentiation method involving an induction period of 5 days during which ES cells were cultured in the presence of Wnt/transforming growth factor TGF-β inhibitors and insulin-like growth factor IGF-1 to suppress mesoderm and reinforce presumptive ectoderm and otic lineages. The generated embryoid bodies were then differentiated in medium containing basic fibroblast growth factor (bFGF) for an additional 5 days using either suspension or adherent culture methods. Upon completion of differentiation, quantitative polymerase chain reaction analysis and immunostaining monitored the expression of otic/HC progenitor lineage markers. The results indicate that cells differentiated in suspension cultures produced cells expressing otic progenitor/HC markers at a higher efficiency compared with the production of these cell types within adherent cultures. Furthermore, we demonstrated that a fraction of these cells can incorporate into ototoxin-injured mouse postnatal cochlea explants and express MYO7A after transplantation. Copyright © 2016 John Wiley & Sons, Ltd. |
Macherey, O; Cazals, Y Effects of Pulse Shape and Polarity on Sensitivity to Cochlear Implant Stimulation: A Chronic Study in Guinea Pigs Book Chapter Physiology, Psychoacoustics and Cognition in Normal and Impaired Hearing, 894 , p. 133-142, 2016. @inbook{Macherey2016, title = {Effects of Pulse Shape and Polarity on Sensitivity to Cochlear Implant Stimulation: A Chronic Study in Guinea Pigs}, author = {O. Macherey and Y. Cazals}, doi = {10.1007/978-3-319-25474-6_15}, year = {2016}, date = {2016-04-15}, booktitle = {Physiology, Psychoacoustics and Cognition in Normal and Impaired Hearing}, volume = {894}, pages = {133-142}, abstract = {Most cochlear implants (CIs) stimulate the auditory nerve with trains of symmetric biphasic pulses consisting of two phases of opposite polarity. Animal and human studies have shown that both polarities can elicit neural responses. In human CI listeners, studies have shown that at suprathreshold levels, the anodic phase is more effective than the cathodic phase. In contrast, animal studies usually show the opposite trend. Although the reason for this discrepancy remains unclear, computational modelling results have proposed that the degeneration of the peripheral processes of the neurons could lead to a higher efficiency of anodic stimulation. We tested this hypothesis in ten guinea pigs who were deafened with an injection of sysomycin and implanted with a single ball electrode inserted in the first turn of the cochlea. Animals were tested at regular intervals between 1 week after deafening and up to 1 year for some of them. Our hypothesis was that if the effect of polarity is determined by the presence or absence of peripheral processes, the difference in polarity efficiency should change over time because of a progressive neural degeneration. Stimuli consisted of charge-balanced symmetric and asymmetric pulses allowing us to observe the response to each polarity individually. For all stimuli, the inferior colliculus evoked potential was measured. Results show that the cathodic phase was more effective than the anodic phase and that this remained so even several months after deafening. This suggests that neural degeneration cannot entirely account for the higher efficiency of anodic stimulation observed in human CI listeners.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } Most cochlear implants (CIs) stimulate the auditory nerve with trains of symmetric biphasic pulses consisting of two phases of opposite polarity. Animal and human studies have shown that both polarities can elicit neural responses. In human CI listeners, studies have shown that at suprathreshold levels, the anodic phase is more effective than the cathodic phase. In contrast, animal studies usually show the opposite trend. Although the reason for this discrepancy remains unclear, computational modelling results have proposed that the degeneration of the peripheral processes of the neurons could lead to a higher efficiency of anodic stimulation. We tested this hypothesis in ten guinea pigs who were deafened with an injection of sysomycin and implanted with a single ball electrode inserted in the first turn of the cochlea. Animals were tested at regular intervals between 1 week after deafening and up to 1 year for some of them. Our hypothesis was that if the effect of polarity is determined by the presence or absence of peripheral processes, the difference in polarity efficiency should change over time because of a progressive neural degeneration. Stimuli consisted of charge-balanced symmetric and asymmetric pulses allowing us to observe the response to each polarity individually. For all stimuli, the inferior colliculus evoked potential was measured. Results show that the cathodic phase was more effective than the anodic phase and that this remained so even several months after deafening. This suggests that neural degeneration cannot entirely account for the higher efficiency of anodic stimulation observed in human CI listeners. |
Cavalli, E; Casalis, S; Ahmadi, El A; Zira, M; Poracchia-Georged, F; Colé, P Vocabulary skills are well developed in university students with dyslexia: Evidence from multiple case studies Article de journal Research in Developmental Disabilities, 51-52 , p. 89-102, 2016. @article{Cavalli2016, title = {Vocabulary skills are well developed in university students with dyslexia: Evidence from multiple case studies}, author = {E. Cavalli and S. Casalis and A. El Ahmadi and M. Zira and F. Poracchia-Georged and P. Colé}, doi = {10.1016/j.ridd.2016.01.006}, year = {2016}, date = {2016-04-01}, journal = {Research in Developmental Disabilities}, volume = {51-52}, pages = {89-102}, abstract = {Most studies in adults with developmental dyslexia have focused on identifying the deficits responsible for their persistent reading difficulties, but little is known on how these readers manage the intensive exposure to written language required to obtain a university degree. The main objective of this study was to identify certain skills, and specifically vocabulary skills, that French university students with dyslexia have developed and that may contribute to their literacy skills. We tested 20 university students with dyslexia and 20 normal readers (matched on chronological age, gender, nonverbal IQ, and level of education) in reading, phonological, vocabulary breadth (number of known words), and vocabulary depth (accuracy and precision) tasks. In comparing vocabulary measures, we used both Rasch model and single case study methodologies. Results on reading and phonological tasks confirmed the persistence of deficits in written word recognition and phonological skills. However, using the Rasch model we found that the two groups performed at the same level in the vocabulary breadth task, whereas dyslexics systematically outperformed their chronological age controls in the vocabulary depth task. These results are supplemented by multiple case studies. The vocabulary skills of French university students with dyslexia are well developed. Possible interpretations of these results are discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Most studies in adults with developmental dyslexia have focused on identifying the deficits responsible for their persistent reading difficulties, but little is known on how these readers manage the intensive exposure to written language required to obtain a university degree. The main objective of this study was to identify certain skills, and specifically vocabulary skills, that French university students with dyslexia have developed and that may contribute to their literacy skills. We tested 20 university students with dyslexia and 20 normal readers (matched on chronological age, gender, nonverbal IQ, and level of education) in reading, phonological, vocabulary breadth (number of known words), and vocabulary depth (accuracy and precision) tasks. In comparing vocabulary measures, we used both Rasch model and single case study methodologies. Results on reading and phonological tasks confirmed the persistence of deficits in written word recognition and phonological skills. However, using the Rasch model we found that the two groups performed at the same level in the vocabulary breadth task, whereas dyslexics systematically outperformed their chronological age controls in the vocabulary depth task. These results are supplemented by multiple case studies. The vocabulary skills of French university students with dyslexia are well developed. Possible interpretations of these results are discussed. |
Gale, S; Prsa, M; Schurger, A; Gay, A; Paillard, A; Herbelin, B; Guyot, J-P; Lopez, C; Blanke, O Oscillatory neural responses evoked by natural vestibular stimuli in humans Article de journal Journal of Neurophysiology, 115 (3), p. 1228-1242, 2016. @article{Gale2016, title = {Oscillatory neural responses evoked by natural vestibular stimuli in humans}, author = {S. Gale and M. Prsa and A. Schurger and A. Gay and A. Paillard and B. Herbelin and J-P. Guyot and C. Lopez and O. Blanke}, doi = {10.1152/jn.00153.2015}, year = {2016}, date = {2016-03-01}, journal = {Journal of Neurophysiology}, volume = {115}, number = {3}, pages = {1228-1242}, abstract = {While there have been numerous studies of the vestibular system in mammals, less is known about the brain mechanisms of vestibular processing in humans. In particular, of the studies that have been carried out in humans over the last 30 years, none has investigated how vestibular stimulation (VS) affects cortical oscillations. Here we recorded high-density electroencephalography (EEG) in healthy human subjects and a group of bilateral vestibular loss patients (BVPs) undergoing transient and constant-velocity passive whole body yaw rotations, focusing our analyses on the modulation of cortical oscillations in response to natural VS. The present approach overcame significant technical challenges associated with combining natural VS with human electrophysiology and reveals that both transient and constant-velocity VS are associated with a prominent suppression of alpha power (8–13 Hz). Alpha band suppression was localized over bilateral temporo-parietal scalp regions, and these alpha modulations were significantly smaller in BVPs. We propose that suppression of oscillations in the alpha band over temporo-parietal scalp regions reflects cortical vestibular processing, potentially comparable with alpha and mu oscillations in the visual and sensorimotor systems, respectively, opening the door to the investigation of human cortical processing under various experimental conditions during natural VS. Copyright © 2016 the American Physiological Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } While there have been numerous studies of the vestibular system in mammals, less is known about the brain mechanisms of vestibular processing in humans. In particular, of the studies that have been carried out in humans over the last 30 years, none has investigated how vestibular stimulation (VS) affects cortical oscillations. Here we recorded high-density electroencephalography (EEG) in healthy human subjects and a group of bilateral vestibular loss patients (BVPs) undergoing transient and constant-velocity passive whole body yaw rotations, focusing our analyses on the modulation of cortical oscillations in response to natural VS. The present approach overcame significant technical challenges associated with combining natural VS with human electrophysiology and reveals that both transient and constant-velocity VS are associated with a prominent suppression of alpha power (8–13 Hz). Alpha band suppression was localized over bilateral temporo-parietal scalp regions, and these alpha modulations were significantly smaller in BVPs. We propose that suppression of oscillations in the alpha band over temporo-parietal scalp regions reflects cortical vestibular processing, potentially comparable with alpha and mu oscillations in the visual and sensorimotor systems, respectively, opening the door to the investigation of human cortical processing under various experimental conditions during natural VS. Copyright © 2016 the American Physiological Society |
Lopez, C The vestibular system: balancing more than just the body Article de journal Current Opinion in Neurology, 29 (1), p. 74-83, 2016. @article{Lopez2016, title = {The vestibular system: balancing more than just the body}, author = {C. Lopez}, doi = {10.1097/WCO.0000000000000286}, year = {2016}, date = {2016-02-01}, journal = {Current Opinion in Neurology}, volume = {29}, number = {1}, pages = {74-83}, abstract = {PURPOSE OF REVIEW: The review presents a selection of recent studies in the field of vestibular neuroscience, including how vestibular stimulation modulates space and body perception. RECENT FINDINGS: Recent neuroimaging studies identified the operculo-insular/retroinsular cortex as the core vestibular cortex and showed how it is reorganized after vestibular dysfunctions. Subliminal galvanic vestibular stimulation (GVS) induces long-term reduction of hemispatial neglect and improves vertical perception in stroke patients, but the underlying mechanisms remain to be identified. Healthy volunteer research suggests that GVS and caloric vestibular stimulation (CVS) modulate visual and somatosensory processing and that beneficial effects of GVS/CVS in stroke patients are not limited to merely rebalancing brain hemispheric activity. Another mechanism would be that GVS/CVS anchors the self to the body, thus promoting an egocentric frame of reference. SUMMARY: In addition to 'balancing the body', the vestibular cortical network contributes to modulate space, body and self-awareness. Emerging evidence suggests that the vestibular network expands into dimensions of emotion processing, mental health, and social cognition. Here, the importance of connecting vestibular physiology, affective neuroscience, and social neuroscience to better understand the psychological aspects of vertigo in otoneurology is discussed. }, keywords = {}, pubstate = {published}, tppubtype = {article} } PURPOSE OF REVIEW: The review presents a selection of recent studies in the field of vestibular neuroscience, including how vestibular stimulation modulates space and body perception. RECENT FINDINGS: Recent neuroimaging studies identified the operculo-insular/retroinsular cortex as the core vestibular cortex and showed how it is reorganized after vestibular dysfunctions. Subliminal galvanic vestibular stimulation (GVS) induces long-term reduction of hemispatial neglect and improves vertical perception in stroke patients, but the underlying mechanisms remain to be identified. Healthy volunteer research suggests that GVS and caloric vestibular stimulation (CVS) modulate visual and somatosensory processing and that beneficial effects of GVS/CVS in stroke patients are not limited to merely rebalancing brain hemispheric activity. Another mechanism would be that GVS/CVS anchors the self to the body, thus promoting an egocentric frame of reference. SUMMARY: In addition to 'balancing the body', the vestibular cortical network contributes to modulate space, body and self-awareness. Emerging evidence suggests that the vestibular network expands into dimensions of emotion processing, mental health, and social cognition. Here, the importance of connecting vestibular physiology, affective neuroscience, and social neuroscience to better understand the psychological aspects of vertigo in otoneurology is discussed. |
Régner, I; Mazerolle, M; ALESCIO-LAUTIER, Béatrice; Clarys, D; Michel, B; Pascalien, M; Paolino, P; Rigalleau, F; Sambuchi, N; Huguet, P Aging Stereotypes Must be Taken Into Account for the Diagnosis of Prodromal and Early Alzheimer Disease Article de journal Alzheimer disease and associated disorders, 30 (1), p. 77-79, 2016. @article{Regner2016, title = {Aging Stereotypes Must be Taken Into Account for the Diagnosis of Prodromal and Early Alzheimer Disease}, author = {I. Régner and M. Mazerolle and Béatrice ALESCIO-LAUTIER and D. Clarys and B. Michel and M. Pascalien and P. Paolino and F. Rigalleau and N. Sambuchi and P. Huguet}, doi = {10.1097/WAD.0000000000000129}, year = {2016}, date = {2016-01-01}, journal = {Alzheimer disease and associated disorders}, volume = {30}, number = {1}, pages = {77-79}, abstract = {Because of a dramatic increase of older people worldwide, screening for prodromal state of Alzheimer disease (AD) is a major societal challenge. Many individuals diagnosed with prodromal AD, do not convert to AD, some remaining stable and others reversing back to normal. We argue that an important source of this overdiagnosis comes from negative aging stereotypes (eg, the culturally shared beliefs that aging inescapably causes severe cognitive decline and diseases). Many laboratory studies show that such stereotypes impair memory performance in healthy older adults, producing inflated age differences. Research is needed to examine how aging stereotypes implicitly permeate neuropsychological testing and contribute to false positives.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Because of a dramatic increase of older people worldwide, screening for prodromal state of Alzheimer disease (AD) is a major societal challenge. Many individuals diagnosed with prodromal AD, do not convert to AD, some remaining stable and others reversing back to normal. We argue that an important source of this overdiagnosis comes from negative aging stereotypes (eg, the culturally shared beliefs that aging inescapably causes severe cognitive decline and diseases). Many laboratory studies show that such stereotypes impair memory performance in healthy older adults, producing inflated age differences. Research is needed to examine how aging stereotypes implicitly permeate neuropsychological testing and contribute to false positives. |
2015 |
Tighilet, B; Leonard, J; Bernard-Demanze, L; Lacour, M European Journal of Pharmacology, 769 , p. 342-349, 2015. @article{Tighilet2015, title = {Comparative analysis of pharmacological treatments with N-acetyl-DL-leucine (Tanganil) and its two isomers (N-acetyl-L-leucine and N-acetyl-D-leucine) on vestibular compensation: Behavioral investigation in the cat}, author = {B. Tighilet and J. Leonard and L. Bernard-Demanze and M. Lacour}, doi = {10.1016/j.ejphar.2015.11.041}, year = {2015}, date = {2015-12-15}, journal = {European Journal of Pharmacology}, volume = {769}, pages = {342-349}, abstract = {Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. Copyright © 2015 Elsevier B.V. All rights reserved. }, keywords = {}, pubstate = {published}, tppubtype = {article} } Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. Copyright © 2015 Elsevier B.V. All rights reserved. |
Sambucci, N; Muraccioli, I; Alescio-Lautier, B; Paban, V; Sambuc, R; Jouvé, E; Geda, Y E; Petersen, R K; Michel, B F Subjective cognitive impairment and Alzheimer's disease: a two year follow up of 51 subjects during two years Article de journal Geriatr Psychol Neuropsychiatr Vieil., 13 (4), p. 462-471, 2015. @article{Sambucci2015z, title = {Subjective cognitive impairment and Alzheimer's disease: a two year follow up of 51 subjects during two years}, author = {N. Sambucci and I. Muraccioli and B. Alescio-Lautier and V. Paban and R. Sambuc and E. Jouvé and Y. E. Geda and R. K. Petersen and B. F. Michel}, doi = {10.1684/pnv.2015.0575}, year = {2015}, date = {2015-12-04}, journal = {Geriatr Psychol Neuropsychiatr Vieil.}, volume = {13}, number = {4}, pages = {462-471}, abstract = {Subjective cognitive impairment (SCI) is defined by a state of subjective complaint, without objective cognitive deterioration. Amnestic mild cognitive impairment (A-MCI), which characterizes a syndrome between normal cognitive aging and early Alzheimer's disease (E-AD), is preceded by A-MCI from many years. SCI expresses a metacognitive impairment. A cohort of 51 subjects [7 normal controls (NC), 28 SCI, 12 A-MCI and 5 E-AD] was followed up during 24 months, with a neuropsychological evaluation each 6 months during 1 year (V1, V2, V3), then 1 year later (V4). Among the 28 SCI, 6 converted to A-MCI at V4 (21.42%), 1 to A-MCI-A at V3, then to E-AD at V4. These results suggest a continuum from SCI to A-MCI, and E-AD. Progressive SCI differed from non-progressive SCI on verbal episodic memory and executive functions tests at the initial examination. MRI showed anterior cingular atrophy in all SCI patients but hippocampal atrophy was only observed in 20 patients. Our results suggest that metacognition impairment is the expression of a dysfunction in the anterior pre-frontal cortex, in correlation with a syndrome of hyper-attention.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Subjective cognitive impairment (SCI) is defined by a state of subjective complaint, without objective cognitive deterioration. Amnestic mild cognitive impairment (A-MCI), which characterizes a syndrome between normal cognitive aging and early Alzheimer's disease (E-AD), is preceded by A-MCI from many years. SCI expresses a metacognitive impairment. A cohort of 51 subjects [7 normal controls (NC), 28 SCI, 12 A-MCI and 5 E-AD] was followed up during 24 months, with a neuropsychological evaluation each 6 months during 1 year (V1, V2, V3), then 1 year later (V4). Among the 28 SCI, 6 converted to A-MCI at V4 (21.42%), 1 to A-MCI-A at V3, then to E-AD at V4. These results suggest a continuum from SCI to A-MCI, and E-AD. Progressive SCI differed from non-progressive SCI on verbal episodic memory and executive functions tests at the initial examination. MRI showed anterior cingular atrophy in all SCI patients but hippocampal atrophy was only observed in 20 patients. Our results suggest that metacognition impairment is the expression of a dysfunction in the anterior pre-frontal cortex, in correlation with a syndrome of hyper-attention. |
Pourcin, L; Springer-Charolles, L; Ahmadi, El A; Cole, P Reading and related skills in Grades 6, 7, 8 and 9: French normative data from EVALEC Article de journal Revue Européenne de Psychologie Appliquée/European Review of Applied Psychology, 1780 (1), p. 23-37, 2015. @article{Pourcin2015, title = {Reading and related skills in Grades 6, 7, 8 and 9: French normative data from EVALEC}, author = {L. Pourcin and L. Springer-Charolles and A. El Ahmadi and P. Cole}, doi = {10.1016/j.erap.2015.11.002}, year = {2015}, date = {2015-11-10}, journal = {Revue Européenne de Psychologie Appliquée/European Review of Applied Psychology}, volume = {1780}, number = {1}, pages = {23-37}, abstract = {Introduction To appropriately assess reading difficulties, tests designed according to an appropriate theoretical framework and based on normative data are required. Objective We used EVALEC (Sprenger-Charolles, Colé, Béchennec, & Kipffer-Piquard, 2005) to collect data on the word-level reading skills and reading-related skills (phonemic awareness, phonological short-term memory, and rapid naming) of middle school children (Grades 6 to 9, about 80 in each grade). Method In the tests focused on word-level reading skills, the effects of regularity (regular vs. irregular words), lexicality, and length (short vs. long irregular words and pseudowords) were examined. Accuracy and processing times were recorded for all tests. Results The effects of both regularity and lexicality were significant, whatever the measure and independently of grade. Both accuracy and speed were lower for longer pseudowords, whereas length did not have a significant effect on irregular word latencies and, surprisingly, long irregular words were read more accurately than short ones. Reading level as assessed by a standardized test (Lefavrais, 2005) was not predicted by phonological short-term memory; rapid naming (color names) and phonemic awareness were both predictors but, in both cases, only response times predicted reading level. Conclusion These results, and particularly those from the reading tasks, are discussed in relation to models of written-word recognition developed to account for the reading of multisyllabic items (Perry, Ziegler, & Zorzi, 2010) in orthographies shallower than English (Perry, Ziegler, & Zorzi, 2014). Résumé Introduction Des tests conçus selon un cadre théorique approprié et sur la base de données normatives sont nécessaires pour évaluer correctement les difficultés de lecture. Objectif Nous avons utilisé EVALEC (Sprenger-Charolles, Colé, Béchennec, & Kipffer-Piquard, 2005) pour recueillir des données sur les capacités d’identification de mots écrits et celles reliées à la lecture (conscience phonémique, mémoire à court terme phonologique et dénomination rapide) au collège (du grade 6 au grade 9, environ 80 enfants par grade). Méthode Pour les tests évaluant les capacités d’identification de mots écrits, les effets de régularité (mots réguliers vs mots irréguliers), de lexicalité, et de longueur (mots irréguliers courts vs longs comparés à pseudomots court vs long) ont été examinés. Pour tous les tests, la précision et le temps de traitement ont été enregistrés. Résultats Les effets de régularité et lexicalité étaient significatifs, quels que soient la mesure et le grade. Les scores de précision et de vitesse étaient plus faibles pour les pseudomots longs, alors que la longueur n’a pas eu d’effet significatif sur les temps de latences des mots irréguliers et, étonnamment, les mots irréguliers longs ont été lus avec plus de précision que les courts. Le niveau de lecture évalué par un test standardisé (Lefavrais, 2005) n’a pas été prédit par la mémoire à court terme phonologique ; la dénomination rapide (des noms de couleur) et la conscience phonémique étaient deux prédicteurs mais seulement lorsque les temps de réponse pour ces deux tests ont été analysés. Conclusion Ces résultats, et en particulier ceux des tests de lecture, sont discutés en relation avec les modèles de reconnaissance des mots écrits développés pour rendre compte de la lecture d’items multisyllabiques (Perry, Ziegler, & Zorzi, 2010) dans des orthographes moins profondes que celles de l’anglais (Perry, Ziegler, & Zorzi, 2014).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Introduction To appropriately assess reading difficulties, tests designed according to an appropriate theoretical framework and based on normative data are required. Objective We used EVALEC (Sprenger-Charolles, Colé, Béchennec, & Kipffer-Piquard, 2005) to collect data on the word-level reading skills and reading-related skills (phonemic awareness, phonological short-term memory, and rapid naming) of middle school children (Grades 6 to 9, about 80 in each grade). Method In the tests focused on word-level reading skills, the effects of regularity (regular vs. irregular words), lexicality, and length (short vs. long irregular words and pseudowords) were examined. Accuracy and processing times were recorded for all tests. Results The effects of both regularity and lexicality were significant, whatever the measure and independently of grade. Both accuracy and speed were lower for longer pseudowords, whereas length did not have a significant effect on irregular word latencies and, surprisingly, long irregular words were read more accurately than short ones. Reading level as assessed by a standardized test (Lefavrais, 2005) was not predicted by phonological short-term memory; rapid naming (color names) and phonemic awareness were both predictors but, in both cases, only response times predicted reading level. Conclusion These results, and particularly those from the reading tasks, are discussed in relation to models of written-word recognition developed to account for the reading of multisyllabic items (Perry, Ziegler, & Zorzi, 2010) in orthographies shallower than English (Perry, Ziegler, & Zorzi, 2014). Résumé Introduction Des tests conçus selon un cadre théorique approprié et sur la base de données normatives sont nécessaires pour évaluer correctement les difficultés de lecture. Objectif Nous avons utilisé EVALEC (Sprenger-Charolles, Colé, Béchennec, & Kipffer-Piquard, 2005) pour recueillir des données sur les capacités d’identification de mots écrits et celles reliées à la lecture (conscience phonémique, mémoire à court terme phonologique et dénomination rapide) au collège (du grade 6 au grade 9, environ 80 enfants par grade). Méthode Pour les tests évaluant les capacités d’identification de mots écrits, les effets de régularité (mots réguliers vs mots irréguliers), de lexicalité, et de longueur (mots irréguliers courts vs longs comparés à pseudomots court vs long) ont été examinés. Pour tous les tests, la précision et le temps de traitement ont été enregistrés. Résultats Les effets de régularité et lexicalité étaient significatifs, quels que soient la mesure et le grade. Les scores de précision et de vitesse étaient plus faibles pour les pseudomots longs, alors que la longueur n’a pas eu d’effet significatif sur les temps de latences des mots irréguliers et, étonnamment, les mots irréguliers longs ont été lus avec plus de précision que les courts. Le niveau de lecture évalué par un test standardisé (Lefavrais, 2005) n’a pas été prédit par la mémoire à court terme phonologique ; la dénomination rapide (des noms de couleur) et la conscience phonémique étaient deux prédicteurs mais seulement lorsque les temps de réponse pour ces deux tests ont été analysés. Conclusion Ces résultats, et en particulier ceux des tests de lecture, sont discutés en relation avec les modèles de reconnaissance des mots écrits développés pour rendre compte de la lecture d’items multisyllabiques (Perry, Ziegler, & Zorzi, 2010) dans des orthographes moins profondes que celles de l’anglais (Perry, Ziegler, & Zorzi, 2014). |
Besnard, S; Lopez, C; Brandt, T; Denise, P; Smith, P F Editorial: The Vestibular System in Cognitive and Memory Processes in Mammalians Article de journal Frontiers in Integrative Neuroscience, 2015. @article{Besnard2015, title = {Editorial: The Vestibular System in Cognitive and Memory Processes in Mammalians}, author = {S. Besnard and C. Lopez and T. Brandt and P. Denise and P. F. Smith}, doi = {10.3389/fnint.2015.00055}, year = {2015}, date = {2015-11-10}, journal = {Frontiers in Integrative Neuroscience}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Cazals, Y; Bévengut, M; Zanella, S; Brocard, F; Barhanin, J; Gestreau, C KCNK5 channels mostly expressed in cochlear outer sulcus cells are indispensable for hearing Article de journal Nature Communications, 2015. @article{Cazals2015, title = {KCNK5 channels mostly expressed in cochlear outer sulcus cells are indispensable for hearing}, author = {Y. Cazals and M. Bévengut and S. Zanella and F. Brocard and J. Barhanin and C. Gestreau}, doi = {10.1038/ncomms9780}, year = {2015}, date = {2015-10-01}, journal = {Nature Communications}, abstract = {In the cochlea, K(+) is essential for mechano-electrical transduction. Here, we explore cochlear structure and function in mice lacking K(+) channels of the two-pore domain family. A profound deafness associated with a decrease in endocochlear potential is found in adult Kcnk5(-/-) mice. Hearing occurs around postnatal day 19 (P19), and completely disappears 2 days later. At P19, Kcnk5(-/-) mice have a normal endolymphatic [K(+)] but a partly lowered endocochlear potential. Using Lac-Z as a gene reporter, KCNK5 is mainly found in outer sulcus Claudius', Boettcher's and root cells. Low levels of expression are also seen in the spiral ganglion, Reissner's membrane and stria vascularis. Essential channels (KCNJ10 and KCNQ1) contributing to K(+) secretion in stria vascularis have normal expression in Kcnk5(-/-) mice. Thus, KCNK5 channels are indispensable for the maintenance of hearing. Among several plausible mechanisms, we emphasize their role in K(+) recycling along the outer sulcus lateral route.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the cochlea, K(+) is essential for mechano-electrical transduction. Here, we explore cochlear structure and function in mice lacking K(+) channels of the two-pore domain family. A profound deafness associated with a decrease in endocochlear potential is found in adult Kcnk5(-/-) mice. Hearing occurs around postnatal day 19 (P19), and completely disappears 2 days later. At P19, Kcnk5(-/-) mice have a normal endolymphatic [K(+)] but a partly lowered endocochlear potential. Using Lac-Z as a gene reporter, KCNK5 is mainly found in outer sulcus Claudius', Boettcher's and root cells. Low levels of expression are also seen in the spiral ganglion, Reissner's membrane and stria vascularis. Essential channels (KCNJ10 and KCNQ1) contributing to K(+) secretion in stria vascularis have normal expression in Kcnk5(-/-) mice. Thus, KCNK5 channels are indispensable for the maintenance of hearing. Among several plausible mechanisms, we emphasize their role in K(+) recycling along the outer sulcus lateral route. |
Farley, Brandon J; Noreña, Arnaud J Membrane potential dynamics of populations of cortical neurons during auditory streaming Article de journal Journal of Neurophysiology, 2015. @article{Farley2015, title = {Membrane potential dynamics of populations of cortical neurons during auditory streaming}, author = {Brandon J. Farley and Arnaud J. Noreña}, doi = {10.1152/jn.00545.2015}, year = {2015}, date = {2015-10-01}, journal = {Journal of Neurophysiology}, abstract = {How a mixture of acoustic sources is perceptually organized into discrete auditory objects remains unclear. One current hypothesis postulates that perceptual segregation of different sources is related to the spatiotemporal separation of cortical responses induced by each acoustic source or stream. In the present study, the dynamics of subthreshold membrane potential activity were measured across the entire tonotopic axis of the rodent primary auditory cortex during the auditory streaming paradigm using voltage-sensitive dye imaging. Consistent with the proposed hypothesis, we observed enhanced spatiotemporal segregation of cortical responses to alternating tone sequences as their frequency separation or presentation rate was increased, both manipulations known to promote stream segregation. However, across most streaming paradigm conditions tested, a substantial cortical region maintaining a response to both tones coexisted with more peripheral cortical regions responding more selectively to one of them. We propose that these coexisting subthreshold representation types could provide neural substrates to support the flexible switching between the integrated and segregated streaming percepts. Copyright © 2015 the American Physiological Society.}, key = {auditory scene analysis; bistability; cocktail party; neural adaptation; perceptual segregation}, keywords = {}, pubstate = {published}, tppubtype = {article} } How a mixture of acoustic sources is perceptually organized into discrete auditory objects remains unclear. One current hypothesis postulates that perceptual segregation of different sources is related to the spatiotemporal separation of cortical responses induced by each acoustic source or stream. In the present study, the dynamics of subthreshold membrane potential activity were measured across the entire tonotopic axis of the rodent primary auditory cortex during the auditory streaming paradigm using voltage-sensitive dye imaging. Consistent with the proposed hypothesis, we observed enhanced spatiotemporal segregation of cortical responses to alternating tone sequences as their frequency separation or presentation rate was increased, both manipulations known to promote stream segregation. However, across most streaming paradigm conditions tested, a substantial cortical region maintaining a response to both tones coexisted with more peripheral cortical regions responding more selectively to one of them. We propose that these coexisting subthreshold representation types could provide neural substrates to support the flexible switching between the integrated and segregated streaming percepts. Copyright © 2015 the American Physiological Society. |
Lopez, C; Falconer, C J; Deroualle, D; Mast, F W In the presence of others: self-location, balance control and vestibular processing Article de journal Neurophysiologie Clinique/Clinical Neurophysiology, 45 (4-5), p. 241-254, 2015. @article{Lopez2015b, title = {In the presence of others: self-location, balance control and vestibular processing}, author = {C. Lopez and C. J. Falconer and D. Deroualle and F. W. Mast}, doi = {10.1016/j.neucli.2015.09.001}, year = {2015}, date = {2015-09-11}, journal = {Neurophysiologie Clinique/Clinical Neurophysiology}, volume = {45}, number = {4-5}, pages = {241-254}, abstract = {The degree to which others in our environment influence sensorimotor processing has been a particular focus of cognitive neuroscience for the past two decades. This process of self-other resonance, or shared body representation, has only recently been extended to more global bodily processes such as self-location, self-motion perception, balance and perspective taking. In this review, we outline these previously overlooked areas of research to bridge the distinct field of social neuroscience with global self-perception, vestibular processing and postural control. Firstly, we outline research showing that the presence and movement of others can modulate two fundamental experiences of the self: self-location (the experience of where the self is located in space) and self-motion perception (the experience that oneself has moved or has been moved in space). Secondly, we outline recent research that has shown perturbations in balance control as a result of instability in others in our environment. Conversely to this, we also highlight studies in virtual reality demonstrating the potential benefits of the presence of others in our environment for those undergoing vestibular rehabilitation. Thirdly, we outline studies of first- and third-person perspective taking, which is the ability to have or take a visuo-spatial perspective within and out-with the confines of our own body. These studies demonstrate a contamination of perspective taking processes (i.e. automatic, implicit, third-person perspective taking) in the presence of others. This collection of research highlights the importance of social cues in the more global processing of the self and its accompanying sensory inputs, particularly vestibular signals. Future research will need to better determine the mechanisms of self-other resonance within these processes, including the role of individual differences in the susceptibility to the influence of another. Copyright © 2015 Elsevier Masson SAS. All rights reserved. }, keywords = {}, pubstate = {published}, tppubtype = {article} } The degree to which others in our environment influence sensorimotor processing has been a particular focus of cognitive neuroscience for the past two decades. This process of self-other resonance, or shared body representation, has only recently been extended to more global bodily processes such as self-location, self-motion perception, balance and perspective taking. In this review, we outline these previously overlooked areas of research to bridge the distinct field of social neuroscience with global self-perception, vestibular processing and postural control. Firstly, we outline research showing that the presence and movement of others can modulate two fundamental experiences of the self: self-location (the experience of where the self is located in space) and self-motion perception (the experience that oneself has moved or has been moved in space). Secondly, we outline recent research that has shown perturbations in balance control as a result of instability in others in our environment. Conversely to this, we also highlight studies in virtual reality demonstrating the potential benefits of the presence of others in our environment for those undergoing vestibular rehabilitation. Thirdly, we outline studies of first- and third-person perspective taking, which is the ability to have or take a visuo-spatial perspective within and out-with the confines of our own body. These studies demonstrate a contamination of perspective taking processes (i.e. automatic, implicit, third-person perspective taking) in the presence of others. This collection of research highlights the importance of social cues in the more global processing of the self and its accompanying sensory inputs, particularly vestibular signals. Future research will need to better determine the mechanisms of self-other resonance within these processes, including the role of individual differences in the susceptibility to the influence of another. Copyright © 2015 Elsevier Masson SAS. All rights reserved. |
Ribot-Ciscar, E; Bovis, Milhe-De V; Aimonetti, J-M; Lapeyssonnie, B; Campana-Salort, E; Pouget, J; Attarian, S Functional impact of vibratory proprioceptive assistance in patients with facioscapulohumeral muscular dystrophy Article de journal Muscle and Nerve, 52 , p. 780-787, 2015. @article{Ribot-Ciscar2015, title = {Functional impact of vibratory proprioceptive assistance in patients with facioscapulohumeral muscular dystrophy}, author = {E. Ribot-Ciscar and V. Milhe-De Bovis and J-M. Aimonetti and B. Lapeyssonnie and E. Campana-Salort and J. Pouget and S. Attarian }, doi = {10.1002/mus.24605}, year = {2015}, date = {2015-09-03}, journal = {Muscle and Nerve}, volume = {52}, pages = {780-787}, abstract = {INTRODUCTION: In this study we analyzed the effects of a rehabilitation method based on the use of vibratory proprioceptive assistance (VPA) in subjects with facioscapulohumeral muscular dystrophy. METHODS: Eight subjects were given 1 month of mechanical vibratory treatment that consisted of 8 sessions of 40-min stimulation on the more affected side. During each session, illusory movements were induced as follows: sensations of extension or flexion of the forearm or elevation of the arm via vibration applied to the distal tendon of the biceps brachialis (BB), triceps brachialis (TB), or pectoralis major muscles (PM), respectively, and of elevation of the arm with extension or flexion of the forearm via vibration of PM+BB or PM+TB, respectively. RESULTS: Treatment led to a significant increase in the amplitude of voluntary shoulder flexion, constant score, and self-rated health. CONCLUSION: VPA may serve as a rehabilitation method for reducing the deleterious effects of decline in motor activities. © 2015 Wiley Periodicals, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } INTRODUCTION: In this study we analyzed the effects of a rehabilitation method based on the use of vibratory proprioceptive assistance (VPA) in subjects with facioscapulohumeral muscular dystrophy. METHODS: Eight subjects were given 1 month of mechanical vibratory treatment that consisted of 8 sessions of 40-min stimulation on the more affected side. During each session, illusory movements were induced as follows: sensations of extension or flexion of the forearm or elevation of the arm via vibration applied to the distal tendon of the biceps brachialis (BB), triceps brachialis (TB), or pectoralis major muscles (PM), respectively, and of elevation of the arm with extension or flexion of the forearm via vibration of PM+BB or PM+TB, respectively. RESULTS: Treatment led to a significant increase in the amplitude of voluntary shoulder flexion, constant score, and self-rated health. CONCLUSION: VPA may serve as a rehabilitation method for reducing the deleterious effects of decline in motor activities. © 2015 Wiley Periodicals, Inc. |
Publications scientifiquesSoleil Digital2018-01-24T11:43:27+01:00