Time course of bilateral corticospinal tract excitability in the motor-learning process
Time course of bilateral corticospinal tract excitability in the motor-learning process
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DOI：
10.1016/j.neulet.2019.134410
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发表时间：
2019-10-15
影响因子：
2.5
通讯作者：
Onishi, Hideaki
中科院分区：
文献类型：
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作者：
Miyaguchi, Shota;Yamaguchi, Mifuyu;Onishi, Hideaki
虽然运动学习改变皮质脊髓束的兴奋性是已知的，但运动学习过程中双侧皮质脊髓束兴奋性的时程尚未阐明。本研究旨在探讨运动学习过程中双侧皮质脊髓束兴奋性的时程变化。16名受试者进行了10次视觉跟踪任务的试验，使用他们的右手食指一分钟。视觉跟踪任务的运动强度范围为最大食指外展力的5%-17%，运动频率为0.5 Hz。为了评估双侧皮质脊髓兴奋性，我们在每次试验之间用经颅磁刺激刺激双侧初级运动皮层，并测量双侧第一背侧骨间肌（FDI）的运动诱发电位（MEP）。运动能力在第6次试验时迅速提高（P < 0.05），从第7次到第10次试验运动能力没有变化。右侧FDI的MEP波幅从第5次到第9次较任务前显著增加（P < 0.05）。相反，MEP幅度的左FDI没有改变在运动学习过程中。这项研究表明，初级运动皮层的兴奋性对运动肌肉的对侧增加，在运动学习的后期阶段和同侧的运动肌肉的初级运动皮层的兴奋性并没有改变运动学习的过程中。
Although it is known that motor learning changes the corticospinal tract excitability, the time course of bilateral corticospinal tract excitability in the motor-learning process has not been clarified. The study aimed to investigate the time course of bilateral corticospinal tract excitability during the motor-learning process. Sixteen subjects performed 10 trials of the visuomotor tracking task by using their right index finger for one minute. The movement intensity of the visuomotor tracking task ranged from 5%-17% of the maximum index finger abduction force and the movement frequency was 0.5 Hz. To assess bilateral corticospinal excitability, we stimulated the bilateral primary motor cortex with transcranial magnetic stimulation between each trial and measured motor-evoked potential (MEP) from the bilateral first dorsal interosseous (FDI) muscle. Motor performance improved rapidly to the sixth trial (P < 0.05), and motor performance did not change from the seventh to the tenth trial. The MEP amplitude of the right FDI increased significantly from the fifth to the ninth trial relative to that before the task (P < 0.05). Conversely, the MEP amplitude of the left FDI did not change during the motor-learning process. This study revealed that primary motor cortex excitability on the contralateral side to the exercising muscle increased in the late motor learning stage and that primary motor cortex excitability on the ipsilateral side to the exercising muscle did not change in the motor-learning process.