Effect of contraction intensity on sympathetic nerve activity to active human skeletal muscle

The effect of contraction intensity on muscle sympathetic nerve activity (MSNA) to active human limbs has not been established. To address this, MSNA was recorded from the left peroneal nerve during and after dorsiflexion contractions sustained for 2 min by the left leg at ~10, 25, and 40% MVC. To e...

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Autores principales: Boulton, Daniel, Taylor, Chloe E., Macefield, Vaughan G., Green, Simon
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4042086/
https://www.ncbi.nlm.nih.gov/pubmed/24917823
http://dx.doi.org/10.3389/fphys.2014.00194
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author Boulton, Daniel
Taylor, Chloe E.
Macefield, Vaughan G.
Green, Simon
author_facet Boulton, Daniel
Taylor, Chloe E.
Macefield, Vaughan G.
Green, Simon
author_sort Boulton, Daniel
collection PubMed
description The effect of contraction intensity on muscle sympathetic nerve activity (MSNA) to active human limbs has not been established. To address this, MSNA was recorded from the left peroneal nerve during and after dorsiflexion contractions sustained for 2 min by the left leg at ~10, 25, and 40% MVC. To explore the involvement of the muscle metaboreflex, limb ischemia was imposed midway during three additional contractions and maintained during recovery. Compared with total MSNA at rest (11.5 ± 4.1 mv(.)min(−1)), MSNA in the active leg increased significantly at the low (21.9 ± 13.6 mv(.)min(−1)), medium (30.5 ± 20.8 mv(.)min(−1)), and high (50.0 ± 24.5 mv(.)min(−1)) intensities. This intensity-dependent effect was more strongly associated with increases in MSNA burst amplitude than burst frequency. Total MSNA then returned to resting levels within the first minute of recovery. Limb ischemia had no significant influence on the intensity-dependent rise in MSNA or its decline during recovery in the active leg. These findings reveal intensity-dependent increases in total MSNA and burst amplitude to contracting human skeletal muscle that do not appear to involve the muscle metaboreflex.
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spelling pubmed-40420862014-06-10 Effect of contraction intensity on sympathetic nerve activity to active human skeletal muscle Boulton, Daniel Taylor, Chloe E. Macefield, Vaughan G. Green, Simon Front Physiol Neurology The effect of contraction intensity on muscle sympathetic nerve activity (MSNA) to active human limbs has not been established. To address this, MSNA was recorded from the left peroneal nerve during and after dorsiflexion contractions sustained for 2 min by the left leg at ~10, 25, and 40% MVC. To explore the involvement of the muscle metaboreflex, limb ischemia was imposed midway during three additional contractions and maintained during recovery. Compared with total MSNA at rest (11.5 ± 4.1 mv(.)min(−1)), MSNA in the active leg increased significantly at the low (21.9 ± 13.6 mv(.)min(−1)), medium (30.5 ± 20.8 mv(.)min(−1)), and high (50.0 ± 24.5 mv(.)min(−1)) intensities. This intensity-dependent effect was more strongly associated with increases in MSNA burst amplitude than burst frequency. Total MSNA then returned to resting levels within the first minute of recovery. Limb ischemia had no significant influence on the intensity-dependent rise in MSNA or its decline during recovery in the active leg. These findings reveal intensity-dependent increases in total MSNA and burst amplitude to contracting human skeletal muscle that do not appear to involve the muscle metaboreflex. Frontiers Media S.A. 2014-06-03 /pmc/articles/PMC4042086/ /pubmed/24917823 http://dx.doi.org/10.3389/fphys.2014.00194 Text en Copyright © 2014 Boulton, Taylor, Macefield and Green. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neurology
Boulton, Daniel
Taylor, Chloe E.
Macefield, Vaughan G.
Green, Simon
Effect of contraction intensity on sympathetic nerve activity to active human skeletal muscle
title Effect of contraction intensity on sympathetic nerve activity to active human skeletal muscle
title_full Effect of contraction intensity on sympathetic nerve activity to active human skeletal muscle
title_fullStr Effect of contraction intensity on sympathetic nerve activity to active human skeletal muscle
title_full_unstemmed Effect of contraction intensity on sympathetic nerve activity to active human skeletal muscle
title_short Effect of contraction intensity on sympathetic nerve activity to active human skeletal muscle
title_sort effect of contraction intensity on sympathetic nerve activity to active human skeletal muscle
topic Neurology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4042086/
https://www.ncbi.nlm.nih.gov/pubmed/24917823
http://dx.doi.org/10.3389/fphys.2014.00194
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