Motor subcircuits mediating the control of movement extent and speed.
Motor subcircuits mediating the control of movement extent and speed.
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DOI：
10.1152/jn.00323.2003
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发表时间：
2003-12
影响因子：
2.5
通讯作者：
R. Turner;M. Desmurget;J. Grethe;M. D. Crutcher;Scott T. Grafton
中科院分区：
文献类型：
--
作者：
R. Turner;M. Desmurget;J. Grethe;M. D. Crutcher;Scott T. Grafton
在13名健康右利手的成年人中，使用PET局部脑血流量（rCBF）图研究了运动范围、速度和协变量的功能相关性。采用整臂平滑追踪任务，严格控制运动持续时间、误差和反馈控制等潜在混淆。在四次扫描的每一次中，当受试者使用光标控制的光标匹配目标的恒定速度运动时，获得相对rCBF的图像。在扫描之间，受试者完全适应四种光标到光标增益之一，从而允许持续的视觉刺激和手臂运动范围从6到24 cm的眼球运动。受试者没有意识到视觉增益的变化。对手臂和眼睛运动的分析表明，在四种增益条件下，行为的唯一显着差异是手臂运动的程度和速度，这两者之间密切相关。参数统计方法确定的脑区，其中rCBF协变的平均运动程度的个体受试者在个人扫描。增加运动范围与双侧基底节（BG;壳核和苍白球）和同侧小脑的rCBF平行增加相关。在双侧感觉运动皮层中也检测到适度程度的影响。没有显着的反向关系被发现。我们的结论是，一个小的子电路内的电机控制系统有助于控制的运动范围和协变量，BG和小脑在该电路的操作中发挥核心作用。
The functional correlates of movement extent, speed, and covariates were investigated using PET mapping of regional cerebral blood flow (rCBF) in 13 healthy right-handed adults. A whole-arm smooth pursuit tracking task was used to strictly control potential confounds such as movement duration, error, and feedback control. During each of four scans, images of relative rCBF were obtained while subjects matched the constant velocity movements of a target using a joystick-controlled cursor. Between scans, subjects were completely adapted to one of four joystick-to-cursor gains, thereby allowing constant visual stimulation and eye movements across arm movements that ranged in extent from 6 to 24 cm. Subjects were unaware of the changes in visuomotor gain. Analyses of arm and eye movements indicated that the only significant difference in behavior across the four gain conditions was the extent and velocity of arm movements, which were closely correlated with each other. Parametric statistical methods identified brain areas where rCBF covaried with the mean movement extent of individual subjects during individual scans. Increasing movement extent was associated with parallel increases of rCBF in bilateral basal ganglia (BG; putamen and globus pallidus) and ipsilateral cerebellum. Modest extent effects were detected also in the sensorimotor cortices bilaterally. No significant inverse relations were found. We conclude that a small subcircuit within the motor control system contributes to the control of movement extent and covariates and that the BG and cerebellum play central roles in the operation of that circuit.