Motor-unit coherence and its relation with synchrony are influenced by training

Semmler, John G., Sale, Martin V., Meyer, François G. and Nordstrom, Michael A. (2004) Motor-unit coherence and its relation with synchrony are influenced by training. Journal of Neurophysiology, 92 6: 3320-3331. doi:10.1152/jn.00316.2004

Author Semmler, John G.
Sale, Martin V.
Meyer, François G.
Nordstrom, Michael A.
Title Motor-unit coherence and its relation with synchrony are influenced by training
Journal name Journal of Neurophysiology   Check publisher's open access policy
ISSN 0022-3077
Publication date 2004-12
Sub-type Article (original research)
DOI 10.1152/jn.00316.2004
Volume 92
Issue 6
Start page 3320
End page 3331
Total pages 12
Place of publication Bethesda, MD., U.S.A.
Publisher American Physiological Society
Language eng
Subject 1109 Neurosciences
1702 Cognitive Sciences
Formatted abstract
The purpose of the study was to quantify the strength of motor-unit coherence from the left and right first dorsal interosseous muscles in untrained, skill-trained (musicians), and strength-trained (weightlifters) individuals who had long-term specialized use of their hand muscles. The strength of motor-unit coherence was quantified from a total of 394 motor-unit pairs in 13 subjects using data from a previous study in which differences were found in the strength of motor-unit synchronization depending on training status. In the present study, we found that the strength of motor-unit coherence was significantly greater in the left compared with the right hand of untrained right-handed subjects with the largest differences observed between 21 and 24 Hz. The strength of motor-unit coherence was lower in both hands of skill-trained subjects (21–27 Hz) and the right (skilled) hand of untrained subjects (21–24 Hz), whereas the largest motor-unit coherence was observed in both hands of strength-trained subjects (3–9 and 21–27 Hz). A strong curvilinear association was observed between motor-unit synchronization and the integral of coherence at 10–30 Hz in all motor-unit pairs (r2 = 0.77), and was most pronounced in strength-trained subjects (r2 = 0.90). Furthermore, this association was accentuated when using synchronization data with broad peaks (>11 ms), suggesting that the 10- to 30-Hz coherence is due to oscillatory activity in indirect branched common inputs. The altered coherence with training may be due to an interaction between cortical inhibition and the number of direct common inputs to motor neurons in skill- or strength-trained hands.
Keyword Hand muscles
Motor-unit coherence
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
Queensland Brain Institute Publications
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Citation counts: TR Web of Science Citation Count  Cited 63 times in Thomson Reuters Web of Science Article | Citations
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Created: Mon, 12 Apr 2010, 14:58:16 EST by Ms May Balasaize on behalf of Queensland Brain Institute