Demand on skillfulness modulates interhemispheric inhibition of motor cortices.
Demand on skillfulness modulates interhemispheric inhibition of motor cortices.
复制标题
对技巧的需求调节运动皮层的半球间抑制。
DOI：
10.1152/jn.01076.2015
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发表时间：
2016
影响因子：
2.5
通讯作者：
Buetefisch,CathrinM
中科院分区：
文献类型：
--
作者：
Wischnewski,Miles;Kowalski,GregM;Rink,Farrah;Belagaje,SamirR;Haut,MarcW;Hobbs,Gerald;Buetefisch,CathrinM
初级运动皮层（M1）在手部运动控制中的作用尚不清楚。功能性磁共振成像（fMRI）的研究单手的性能报告之间的关系的精确度水平的运动任务和额外的同侧M1（iM1）激活。在本研究中，我们确定是否对运动的准确性的需求影响初级运动皮层（IHI）之间的抑制作用的大小。我们使用经颅磁刺激（TMS）来测量在左手运动任务的运动前期对侧M1（cM1）的iM1的主动IHI（aIHI）。10名健康的参与者操纵操纵杆指向两个不同大小的目标。对于aIHI，条件刺激（CS）被施加到iM1，和测试刺激（TS）到cM1，与10 ms的刺激间的间隔。CS对运动诱发电位（MEP）的抑制作用的量的后续TS被表示为由单个TS诱发的平均MEP幅度的百分比。在运动前aIHI测量的不同时间点，目标大小对aIHI有显著影响。与指向大目标相比，准备指向小目标与较弱的aIHI相关。本研究结果表明，在运动前期，aIHI从iM1上的cM1调制的准确性的运动任务的需求。这是一致的任务功能磁共振成像结果显示双边M1激活高精度的运动，但只有单侧M1活动在低精度的运动。
The role of primary motor cortex (M1) in the control of hand movements is still unclear. Functional magnetic resonance imaging (fMRI) studies of unimanual performance reported a relationship between level of precision of a motor task and additional ipsilateral M1 (iM1) activation. In the present study, we determined whether the demand on accuracy of a movement influences the magnitude of the inhibitory effect between primary motor cortices (IHI). We used transcranial magnetic stimulation (TMS) to measure active IHI (aIHI) of the iM1 on the contralateral M1 (cM1) in the premovement period of a left-hand motor task. Ten healthy participants manipulated a joystick to point to targets of two different sizes. For aIHI, the conditioning stimulus (CS) was applied to iM1, and the test stimulus (TS) to cM1, with an interstimulus interval of 10 ms. The amount of the inhibitory effect of the CS on the motor-evoked potential (MEP) of the subsequent TS was expressed as percentage of the mean MEP amplitude evoked by the single TS. Across different time points of aIHI measurements in the premovement period, there was a significant effect for target size on aIHI. Preparing to point to small targets was associated with weaker aIHI compared with pointing to large targets. The present findings suggest that, during the premovement period, aIHI from iM1 on cM1 is modulated by the demand on accuracy of the motor task. This is consistent with task fMRI findings showing bilateral M1 activation during high-precision movements but only unilateral M1 activity during low-precision movements.