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Neural mechanisms of anticipatory postural adjustment in human

人类预期姿势调整的神经机制

基本信息

批准号：
07680119
负责人：
KASAI Tatsuya
金额：
$ 1.34万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

A biomechanical and neurophysiological analysis of anticipatory postual adjustments associated with the early phase of a voluntary arm movement was carried out in normal subjects. Arm elevation, performed at maximal velocity, was studied with unilateral arm movement in freely and counterbalanced (suspended in a safety harness) standing humans. The ground reaction force of both legs, tengential acceleration of the shank and electromyographic (EMG) activity of the anterior deltoid (AD), biceps femoris (BF) and soleus (Sol) muscles were recorded. Sol H-reflex of both legs were also elicited. In this study, we systematically investigated biomechanical and EMG phenomena that precede and follow the onset of voluntary arm movements. Prior to and during the arm movement (i.e., AD activity), a sequence of EMG modofications occurred in ipsilateral BF and Sol muscles. Those modifications preceding BF activity included silent phases in Sol EMG and depression of Sol H-reflexes. By comparing EMG modifications with depression of the Sol H-reflex, we conclude that Ia and presynaptic inhibitory pathways do not play a specific role in those Sol H-reflex depression. Moreover, because Sol H-reflex depression occurs in both freely standing and counterbalanced postures, anticipatory postural adjustment appear to be preprogramd in the central neuvous systems unrelated to peripheral neural mechanisms. Since changes of EMG activities of ipsilateral BF and Sol appeared simultaneously and Sol H-reflex depressions were dependent on EMG activities of ipsilateral BF,control commands to anticipatory postural adjustment would excite BF and inhibit Sol.

对正常受试者进行了与手臂早期自主运动相关的预期姿势调整的生物力学和神经生理学分析。在自由和平衡(悬挂在安全的安全带上)站立的人中，研究了以最大速度进行的手臂抬高。记录双腿地面反作用力、小腿张力加速度和三角肌、股二头肌、比目鱼肌的肌电活动。双腿SOL H反射也被引出。在这项研究中，我们系统地研究了自主性手臂运动前后的生物力学和肌电现象。在手臂运动(即AD活动)之前和期间，在同侧的BF和SOL肌肉中发生了一系列的EMG改变。BF活动前的改变包括Sol EMG中的静默期和Sol H反射的抑制。通过比较肌电改变和Sol H反射抑制，我们得出结论：Ia和突触前抑制通路在Sol H反射抑制中不起特定作用。此外，因为SOL H反射抑制在自由站立姿势和平衡姿势下都会发生，所以预期的姿势调整似乎是在与周围神经机制无关的中枢神经系统中预先编程的。由于同侧BF和SOL的肌电活动变化是同时出现的，而SOL H反射抑制依赖于同侧BF的EMG活动，因此预见性姿势调整的控制指令将刺激BF并抑制SOL。