Cortical motor regulation during muscle relaxation
Cortical motor regulation during muscle relaxation
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肌肉放松期间的皮质运动调节
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
C. Trompetto
中科院分区：
文献类型：
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作者：
Y. Nakamura;J. Rothwell;Filipović;A. Maruyama;C. Trompetto
研究背景随意收缩可促进大脑皮层对经颅磁刺激的反应。本实验的目的是测试是否从一个恒定的收缩放松伴随着相反的：增加运动皮层的抑制。共入组17例正常受试者。这些实验在恒定等长收缩期间对FDI肌肉进行。采用配对脉冲模式研究MEP、沉默期持续时间和短潜伏期皮质-皮质抑制。在放松的时候。MEP的大小与EMG平行地减小，其作用开始于反应信号后约100 ms。在这第一个100毫秒期间，皮质-皮质抑制没有变化，虽然沉默期短于持续收缩。使用"go/no-go"范式的试验表明，即使受试者期望放松，沉默期也会缩短。在这项任务的放松并没有伴随着任何迹象表明，增加活动的皮质抑制系统。我们认为，从运动皮层输出的撤回比主动抑制过程更重要。
Background Voluntary contraction can facilitate the cortical response to transcranial magnetic stimulation. The purpose of the present experiment was to test whether relaxation from a constant contraction was accompanied by the opposite: increased inhibition of the motor cortex.Methods. A total of 17 normal subjects were enrolled. These experiments were performed on the FDI muscle during a constant isometric contraction. MEPs, silent period duration and short latency cortico-cortical inhibition with a paired pulse paradigm were studied.Results. During relaxation. the size of MEP decreased parallel to the EMG, with the effect beginning about 100 ms after the reaction signal. In this first 100-ms period there was no change in cortico-cortical inhibition, although the silent period was shorter than in sustained contractions. Trials using a "go/no-go" paradigm showed that the shortening of the silent period occurred even when the subject was expecting to relax.Conclusion. Relaxation in this task was not accompanied by any signs of increased activity in cortical inhibitory systems. We suggest that withdrawal of output from the motor cortex is more important than active inhibitory processes.