Remple M S, Bruneau R M, VandenBerg P M, Goertzen C, Kleim J A
Department of Psychology and Neuroscience, University of Lethbridge, 4401 University Dr., Lethbridge, Alberta, Canada, T1K 3M4.
Behav Brain Res. 2001 Sep 14;123(2):133-41. doi: 10.1016/s0166-4328(01)00199-1.
The topography of forelimb movement representations within the rat motor cortex was examined following forelimb strength training. Adult male rats were allocated to either a Power Reaching, Control Reaching or Non-Reaching Condition. Power Reaching rats were trained to grasp and break progressively larger bundles of dried pasta strands with their preferred forelimb. Control Reaching animals were trained to break a single pasta strand and Non-Reaching animals were not trained. Power Reaching animals exhibited a progressive increase in the maximal size of the pasta bundle that could be retrieved during a 30-day training period. Kinematic analyses showed that this improvement was not due to a change in reaching strategy. Intracortical microelectrode stimulation was used to derive maps of forelimb movement representations within the motor cortex of all animals following training. In comparison to Non-Reaching animals, both Power Reaching and Control Reaching animals exhibited a significant increase in the proportion of motor cortex occupied by distal forelimb movement representations (wrist/digit) and a decrease in the proportion of proximal representations (elbow/shoulder). These results demonstrate that the development of skilled forelimb movements, but not increased forelimb strength, was associated with a reorganization of forelimb movement representations within motor cortex.
在前肢力量训练后，对大鼠运动皮层内前肢运动表征的拓扑结构进行了检查。成年雄性大鼠被分配到力量抓取组、对照抓取组或非抓取组。力量抓取组的大鼠被训练用其偏好的前肢抓取并掰断逐渐变大的干面条束。对照抓取组的动物被训练掰断单根面条，而非抓取组的动物不进行训练。在为期30天的训练期内，力量抓取组的动物能够抓取的面条束的最大尺寸逐渐增加。运动学分析表明，这种改善并非由于抓取策略的改变。训练后，使用皮层内微电极刺激来绘制所有动物运动皮层内前肢运动表征的图谱。与非抓取组动物相比，力量抓取组和对照抓取组的动物在前肢远端运动表征（手腕/手指）占据的运动皮层比例上均显著增加，而近端表征（肘部/肩部）的比例则下降。这些结果表明，熟练前肢运动的发展，而非前肢力量的增加，与运动皮层内前肢运动表征的重组有关。
