Monfils M-H, Teskey G C
Behavioural Neuroscience Research Group, Department of Psychology, University of Calgary, 2500 University Drive Northwest, Calgary, Alberta, Canada T2N 1N4.
Neuroscience. 2004;125(2):329-36. doi: 10.1016/j.neuroscience.2004.01.048.
The relation between the acquisition of a skilled motor task and synaptic plasticity in the sensorimotor cortex of the awake, freely behaving rat was examined. Skilled-motor training was previously found to induce a functional reorganization of the caudal forelimb area, and to induce an increase in synaptic efficacy, measured in vitro, on the side contralateral to the reaching forelimb. Here, we repeatedly measured neocortical evoked potential recordings in awake, freely behaving rats to examine whether skilled training would induce changes in polysynaptic efficacy on the side contralateral to the reaching forelimb. We found that the increase in task proficiency, but not the acquisition of task requirements or the maintenance of task proficiency, induced an increase in synaptic efficacy on the side contralateral to the reaching forelimb. We also tested the hypothesis that skilled learning induced potentiation shares similar mechanisms to long-term potentiation (LTP) and long-term depression by artificially manipulating polysynaptic efficacy in skilled rats with high- and low-frequency stimulation. We observed that, compared with the ipsilateral side, less potentiation but more depression could be induced on the side contralateral to the reaching forelimb. We conclude that a transient, network-based LTP-like mechanism operates during the learning of a skilled motor task.
研究了清醒、自由活动大鼠的感觉运动皮层中熟练运动任务的习得与突触可塑性之间的关系。先前发现，熟练运动训练可诱导尾侧前肢区域的功能重组，并在体外测量到，对伸展前肢对侧的突触效能增加。在此，我们反复测量清醒、自由活动大鼠的新皮层诱发电位记录，以检查熟练训练是否会在伸展前肢对侧诱导多突触效能的变化。我们发现，任务熟练程度的提高，而非任务要求的习得或任务熟练程度的维持，会导致伸展前肢对侧的突触效能增加。我们还通过对熟练大鼠进行高频和低频刺激来人工操纵多突触效能，检验了熟练学习诱导的增强与长时程增强（LTP）和长时程抑制具有相似机制的假设。我们观察到，与同侧相比，伸展前肢对侧可诱导的增强较少，但抑制较多。我们得出结论，在熟练运动任务的学习过程中，一种基于网络的短暂的类似LTP的机制发挥作用。
