Change in the ipsilateral motor cortex excitability is independent from a muscle contraction phase during unilateral repetitive isometric contractions.
Change in the ipsilateral motor cortex excitability is independent from a muscle contraction phase during unilateral repetitive isometric contractions.
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DOI：
10.1371/journal.pone.0055083
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Funase K
中科院分区：
文献类型：
--
作者：
Uehara K;Morishita T;Kubota S;Funase K
本研究的目的是探讨在重复等距收缩的单方面食指外展使用经颅磁刺激（TMS）技术同侧（ipsi）和对侧（contra）的初级运动皮层（M1）的兴奋性之间的肌肉收缩相位依赖性的差异。10名健康的右利手受试者参加了这项研究。我们指导他们在1 Hz的听觉提示下进行左食指外展的重复等长收缩。将力输出设定为最大随意收缩（MVC）的10%、30%和50%。从右侧和左侧第一背侧骨间肌（FDI）获得运动诱发电位（MEP）。为了检查肌肉收缩时相依赖性，在肌电图（EMG）开始后的8个不同时间间隔（0，20，40，60，80，100，300或500 ms）触发同侧M1或反侧M1的TMS，当每个时间间隔达到设置触发水平时。此外，为了证明活动性左侧FDI中的整合EMG（iEMG）与同侧M1兴奋性之间的关系，我们评估了TMS发作前100 ms左侧FDI中的iEMG与每个力输出条件下静息/活动FDI中的MEP幅度之间的相关性。虽然反M1兴奋性的EMG发作后，取决于肌肉收缩相显着改变，调制同侧M1兴奋性没有不同的反应，任何肌肉收缩相在10%的MVC条件。此外，我们发现，在所有的力输出条件下，逆M1兴奋性与iEMG显着相关，但同侧M1兴奋性不低于MVC的30%的力输出水平。因此，同侧M1兴奋性的调制是独立的，从收缩阶段的单边重复等长收缩至少低力输出。
The aim of this study was to investigate the difference in a muscle contraction phase dependence between ipsilateral (ipsi)- and contralateral (contra)-primary motor cortex (M1) excitability during repetitive isometric contractions of unilateral index finger abduction using a transcranial magnetic stimulation (TMS) technique. Ten healthy right-handed subjects participated in this study. We instructed them to perform repetitive isometric contractions of the left index finger abduction following auditory cues at 1 Hz. The force outputs were set at 10, 30, and 50% of maximal voluntary contraction (MVC). Motor evoked potentials (MEP) were obtained from the right and left first dorsal interosseous muscles (FDI). To examine the muscle contraction phase dependence, TMS of ipsi-M1 or contra-M1 was triggered at eight different intervals (0, 20, 40, 60, 80, 100, 300, or 500 ms) after electromyogram (EMG) onset when each interval had reached the setup triggering level. Furthermore, to demonstrate the relationships between the integrated EMG (iEMG) in the active left FDI and the ipsi-M1 excitability, we assessed the correlation between the iEMG in the left FDI for the 100 ms preceding TMS onset and the MEP amplitude in the resting/active FDI for each force output condition. Although contra-M1 excitability was significantly changed after the EMG onset that depends on the muscle contraction phase, the modulation of ipsi-M1 excitability did not differ in response to any muscle contraction phase at the 10% of MVC condition. Also, we found that contra-M1 excitability was significantly correlated with iEMG in all force output conditions, but ipsi-M1 excitability was not at force output levels of below 30% of MVC. Consequently, the modulation of ipsi-M1 excitability was independent from the contraction phase of unilateral repetitive isometric contractions at least low force output.
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DOI：
10.1111/j.1460-9568.2010.07567.x
发表时间：
2011-03
期刊：
The European journal of neuroscience
影响因子：
--
作者：
Howatson G;Taylor MB;Rider P;Motawar BR;McNally MP;Solnik S;DeVita P;Hortobágyi T
通讯作者：
Hortobágyi T
影响因子：
4.7
作者：
Muellbacher, W;Facchini, S;Hallett, M
通讯作者：
Hallett, M
影响因子：
2.5
作者：
Morishita, Takuya;Uehara, Kazumasa;Funase, Kozo
通讯作者：
Funase, Kozo
影响因子：
3.7
作者：
Hayashi, Masamichi J.;Saito, Daisuke N.;Sadato, Norihiro
通讯作者：
Sadato, Norihiro
影响因子：
5.5
作者：
JACK, JJB;REDMAN, SJ;WONG, K
通讯作者：
WONG, K