成年大鼠健侧颈7移位术后跨大脑两半球功能重组的脑电生理研究  

Electrophysiological study on the transhemispheric reorganization in primary motor cortex following contralateral C7 nerve root transfer in adult rats

作　　者：李占玉[1] 徐建光[1] 徐文东[1] 顾玉东[1] 

机构地区：[1]复旦大学附属华山医院手外科,上海200040

出　　处：《中华手外科杂志》2007年第1期11-15,共5页Chinese Journal of Hand Surgery

基　　金：国家自然科学基金资助项目（30200288）;国家973创伤基础研究基金资助项目（G1999054202）;复旦大学研究生创新基金资助项目（CQF151802）

摘　　要：目的 研究健侧颈，移位至患侧正中神经术后初级运动皮层跨大脑两半球功能重组的时程，初步探讨该重组的中枢机制。方法 将45只SD雄性大鼠随机分为9组，即正常对照组（1个组），加左侧全臂丛根性撕脱模型和右侧（健侧）颈7移位模型两组在术后3个月、5个月、7个月、10个月共8个时间组，每组5只。采用运动皮层内微电极电刺激技术，定量评价成年大鼠患肢正中神经代表区在双侧初级运动皮层（初级运动皮层，MI）内的可塑性变化。结果在双侧MI电刺激：（1）正常对照组：一侧肢体的正中神经代表区只在其对侧Ⅷ出现。（2）左侧全臂丛根性撕脱模型：在术后3-10个月，患肢的正中神经代表区在双侧Ⅷ均能被诱发出来。（3）健侧颈，移位模型：术后3个月，患肢正中神经代表区在双侧MI均未出现。术后5个月，患肢正中神经代表区仅出现于患肢同侧MI。术后7个月，患肢正中神经代表区在双侧MI均出现。术后10个月，患肢正中神经代表区只出现于患肢对侧MI，代表区面积与正常对照无明显差异，且仍位于原前肢代表区。结论 在健侧颈7移位成年大鼠模型上证实，在术后10个月初级运动皮层出现了跨大脑两半球的功能重组，并初步探讨了其可能的中枢机制。发现了成年哺乳动物周围神经解剖通路改变后发生跨大脑半球功能重组的脑电生理依据。Objective To observe the time course of transhemispheric reorganization in primary motor cortex after contralateral C7 nerve root transfer to the median nerve and investigate the central mechanism of cortical reorganization. Methods Forty-five adult male Sprague-Dawley rats were divided into 9 groups. A non-operative group served as control, while 4 groups had left brachial plexus root avulsion and the other 4 groups had left brachial plexus avulsion and contralateral C7 transfer from the fight side to the left median nerve. Intraeorfical microstimulation was used to study changes of median nerve representing area in bilateral primary motor cortex （MI） at different intervals, namely 3, 5, 7, and 10 months postoperatively. Results After stimulation of bilateral MI in the control group, median nerve representation region of the left forelimb only appeared in the contralateral MI, The median nerve representation region of the affected forelimb did not appear in bilateral MI in the total left brachial plexus root avulsion group up to 10 months postoperatively, In the contralateral Ca transfer group the median nerve representation region of the affected forelimb did not appear in bilateral MI at 3 months, It appeared only in the ipsilateral MI at 5 months after the nerve transfer, At 7 months it appeared in bilateral MI. At 10 months after the nerve transfer, however, the median nerve representation region of the affected forelimb appeared merely in the contraalteral MI, and still located in the former forelimb representation region. Conclusion Transhemisphefic reorganization was confirmed to have taken place in MI following contralateral Ca nerve root transfer in the rat model. The possible mechanisms of transhemispheric reorganization in MI were discussed. It was the first time that the dectrophysiological evidence of transhemispheric reorganization was found after the change of anatomic closed-circuit of adult mammal peripheral nerve.

关 键 词：臂丛 神经移位 脊神经根 大脑皮质 神经元可塑性 

分 类 号：R686[医药卫生—骨科学]