Whishaw I Q, Pellis S M, Gorny B P
Department of Psychology, University of Lethbridge, Alta., Canada.
Behav Brain Res. 1992 Sep 28;50(1-2):93-104. doi: 10.1016/s0166-4328(05)80291-8.
This study examined the contribution of medial frontal cortex (the medial portion of supplementary motor cortex, or Fr1) to the performance of rats on trained, or 'skilled', reaching tasks. Unilateral medial frontal cortex lesions moderately impaired reaching success on a task that demanded accuracy but they did not impair performance on a less demanding reaching task nor did they affect limb preference. Kinematic analyses indicated that the aiming component, in which the forearm of the limb is aligned along the midline of the body by adduction of the elbow, was chronically impaired. Rather than adducting the elbow to aim, the rats used a number of limb and whole body postural adjustments to compensate for incomplete or absent aiming. That medial frontal cortex is involved in the execution of at least one component of skilled reaching implies that a larger area of frontal cortex is involved in skilled limb movement than has been suggested by previous studies. The results also suggest that the different regions of frontal cortex may each have a relatively selective involvement in the execution of only a subset of the movements comprising a reach.
本研究考察了内侧额叶皮质（辅助运动皮质的内侧部分，即Fr1）对大鼠完成训练有素的“熟练”够物任务表现的作用。单侧内侧额叶皮质损伤会适度损害大鼠在要求准确性的任务上的够物成功率，但不会损害在要求较低的够物任务上的表现，也不会影响肢体偏好。运动学分析表明，在该任务中，通过肘部内收使肢体的前臂沿身体中线对齐的瞄准动作长期受损。大鼠不是通过内收肘部来瞄准，而是采用了一些肢体和全身姿势调整来弥补不完整或缺失的瞄准动作。内侧额叶皮质参与了熟练够物至少一个组成部分的执行，这意味着参与熟练肢体运动的额叶皮质区域比先前研究所表明的更大。结果还表明，额叶皮质的不同区域可能各自相对选择性地参与仅构成一次够物动作的一部分运动的执行。
