人类运动前区皮质的功能性特定重组
Neuron 54, 479–490, May 3, 2007Functionally Specific Reorganization in Human Premotor Cortex
人类运动前区皮质的功能性特定重组
SUMMARY
摘要
After unilateral stroke, the dorsal premotor cortex (PMd) in the intact hemisphere is often more active during movement of an affected limb. Whether this contributes to motor recovery is unclear. Functional magnetic resonance imaging (fMRI) was used to investigate short-term reorganization in right PMd after transcranial magnetic stimulation (TMS) disrupted the dominant left PMd, which is specialized for action selection. Even when 1 Hz left PMd TMS had no effect on behavior, there was a compensatory increase in activity in right PMd and connected medial premotor areas. This activity was specific to task periods of action selection as opposed to action execution. Compensatory activation changes were both functionally specific and anatomically specific: the same pattern was not seen after TMS of left sensorimotor cortex. Subsequent TMS of the reorganized right PMd did disrupt performance. Thus, this pattern of functional reorganization has a causal role in preserving behavior after neuronal challenge.
单侧脑梗死后，未受损半球侧的背侧运动前区皮质（PMd）在患肢运动时经常是比较活跃的。这是否能够促进运动恢复尚不清楚。功能核磁成像(fMRI)曾用于研究经颅磁刺激（TMS）断裂的左侧优势半球专门负责动作选择的PMd后，右侧PMd的短期重组。甚至，当1HzTMS左侧PMd在行为上没有疗效时，右侧PMd和连接的内侧运动前区活性也有代偿性的增加。这种活性在动作选择的作业时期而不是动作执行时是特定的。代偿性活性改变是功能特定的和解剖特定的：左侧感觉运动皮质TMS后没有发现同样的改变。重组的右侧PMd在随后的TMS确实影响了执行功能。因此，这种功能重组的形式在神经元损伤后保护行为中有作用。
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