Jacobs K M, Donoghue J P
Brown University, Providence, RI 02912.
Science. 1991 Feb 22;251(4996):944-7. doi: 10.1126/science.2000496.
The primary motor cortex (MI) contains a map organized so that contralateral limb or facial movements are elicited by electrical stimulation within separate medial to lateral MI regions. Within hours of a peripheral nerve transection in adult rats, movements represented in neighboring MI areas are evoked from the cortical territory of the affected body part. One potential mechanism for reorganization is that adjacent cortical regions expand when preexisting lateral excitatory connections are unmasked by decreased intracortical inhibition. During pharmacological blockade of cortical inhibition in one part of the MI representation, movements of neighboring representations were evoked by stimulation in adjacent MI areas. These results suggest that intracortical connections form a substrate for reorganization of cortical maps and that inhibitory circuits are critically placed to maintain or readjust the form of cortical motor representations.
初级运动皮层（MI）包含一种有序排列的图谱，使得对侧肢体或面部运动可通过在MI区域内从内侧到外侧的不同区域进行电刺激来诱发。在成年大鼠外周神经横断后的数小时内，受影响身体部位的皮质区域会诱发相邻MI区域所代表的运动。重组的一种潜在机制是，当预先存在的外侧兴奋性连接因皮质内抑制作用减弱而暴露时，相邻的皮质区域会扩张。在MI代表区的一部分进行皮质抑制的药理学阻断期间，相邻MI区域的刺激会诱发相邻代表区的运动。这些结果表明，皮质内连接形成了皮质图谱重组的基础，并且抑制性回路在维持或重新调整皮质运动代表形式方面起着关键作用。
