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Interhemispheric connectivity during bimanual isometric force generation

Interhemispheric interactions through the corpus callosum play an important role in the control of bimanual forces. However, the extent to which physiological connections between primary motor cortices are modulated during increasing levels of bimanual force generation in intact humans remains poorl...

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Autores principales: Long, Jinyi, Tazoe, Toshiki, Soteropoulos, Demetris S., Perez, Monica A.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Physiological Society 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808122/
https://www.ncbi.nlm.nih.gov/pubmed/26538610
http://dx.doi.org/10.1152/jn.00876.2015
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author Long, Jinyi
Tazoe, Toshiki
Soteropoulos, Demetris S.
Perez, Monica A.
author_facet Long, Jinyi
Tazoe, Toshiki
Soteropoulos, Demetris S.
Perez, Monica A.
author_sort Long, Jinyi
collection PubMed
description Interhemispheric interactions through the corpus callosum play an important role in the control of bimanual forces. However, the extent to which physiological connections between primary motor cortices are modulated during increasing levels of bimanual force generation in intact humans remains poorly understood. Here we studied coherence between electroencephalographic (EEG) signals and the ipsilateral cortical silent period (iSP), two well-known measures of interhemispheric connectivity between motor cortices, during unilateral and bilateral 10%, 40%, and 70% of maximal isometric voluntary contraction (MVC) into index finger abduction. We found that EEG-EEG coherence in the alpha frequency band decreased while the iSP area increased during bilateral compared with unilateral 40% and 70% but not 10% of MVC. Decreases in coherence in the alpha frequency band correlated with increases in the iSP area, and subjects who showed this inverse relation were able to maintain more steady bilateral muscle contractions. To further examine the relationship between the iSP and coherence we electrically stimulated the ulnar nerve at the wrist at the alpha frequency. Electrical stimulation increased coherence in the alpha frequency band and decreased the iSP area during bilateral 70% of MVC. Altogether, our findings demonstrate an inverse relation between alpha oscillations and the iSP during strong levels of bimanual force generation. We suggest that interactions between neural pathways mediating alpha oscillatory activity and transcallosal inhibition between motor cortices might contribute to the steadiness of strong bilateral isometric muscle contractions in intact humans.
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spelling pubmed-48081222016-04-06 Interhemispheric connectivity during bimanual isometric force generation Long, Jinyi Tazoe, Toshiki Soteropoulos, Demetris S. Perez, Monica A. J Neurophysiol Control of Movement Interhemispheric interactions through the corpus callosum play an important role in the control of bimanual forces. However, the extent to which physiological connections between primary motor cortices are modulated during increasing levels of bimanual force generation in intact humans remains poorly understood. Here we studied coherence between electroencephalographic (EEG) signals and the ipsilateral cortical silent period (iSP), two well-known measures of interhemispheric connectivity between motor cortices, during unilateral and bilateral 10%, 40%, and 70% of maximal isometric voluntary contraction (MVC) into index finger abduction. We found that EEG-EEG coherence in the alpha frequency band decreased while the iSP area increased during bilateral compared with unilateral 40% and 70% but not 10% of MVC. Decreases in coherence in the alpha frequency band correlated with increases in the iSP area, and subjects who showed this inverse relation were able to maintain more steady bilateral muscle contractions. To further examine the relationship between the iSP and coherence we electrically stimulated the ulnar nerve at the wrist at the alpha frequency. Electrical stimulation increased coherence in the alpha frequency band and decreased the iSP area during bilateral 70% of MVC. Altogether, our findings demonstrate an inverse relation between alpha oscillations and the iSP during strong levels of bimanual force generation. We suggest that interactions between neural pathways mediating alpha oscillatory activity and transcallosal inhibition between motor cortices might contribute to the steadiness of strong bilateral isometric muscle contractions in intact humans. American Physiological Society 2015-11-04 2016-03-01 /pmc/articles/PMC4808122/ /pubmed/26538610 http://dx.doi.org/10.1152/jn.00876.2015 Text en Copyright © 2016 the American Physiological Society http://creativecommons.org/licenses/by/3.0/deed.en_US Licensed under Creative Commons Attribution CC-BY 3.0 (http://creativecommons.org/licenses/by/3.0/deed.en_US) : © the American Physiological Society.
spellingShingle Control of Movement
Long, Jinyi
Tazoe, Toshiki
Soteropoulos, Demetris S.
Perez, Monica A.
Interhemispheric connectivity during bimanual isometric force generation
title Interhemispheric connectivity during bimanual isometric force generation
title_full Interhemispheric connectivity during bimanual isometric force generation
title_fullStr Interhemispheric connectivity during bimanual isometric force generation
title_full_unstemmed Interhemispheric connectivity during bimanual isometric force generation
title_short Interhemispheric connectivity during bimanual isometric force generation
title_sort interhemispheric connectivity during bimanual isometric force generation
topic Control of Movement
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4808122/
https://www.ncbi.nlm.nih.gov/pubmed/26538610
http://dx.doi.org/10.1152/jn.00876.2015
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