成年大鼠全臂丛根性撕脱伤后初级体感皮层可塑性变化的脑电生理研究  

Electrophysiological study on changes of plasticity of bilateral primary somatosensory cortex following total brachial plexus root avulsion injuries in adult rats

作　　者：李占玉 [1] 徐建光 [2] 徐文东 [2] 顾玉东 [2] 

机构地区：[1]200127,上海第二医科大学附属仁济医院骨科 [2]上海复旦大学附属华山医院手外科

出　　处：《中华手外科杂志》2005年第6期362-364,共3页Chinese Journal of Hand Surgery

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

摘　　要：目的探讨成年大鼠一侧全臂丛根性撕脱伤后双侧初级体感皮层可塑性变化的规律。方法将30只SD雄性大鼠分为6组,分为正常对照组和全臂丛根性撕脱伤术后1d、7d、1个月、3个月、1年共5个时间组,每组5只。采用体感皮层诱发电位(somatosensory evoked potential,SEP)记录法,定量评价一侧全臂丛根性撕脱伤后双侧初级体感皮层(Sml)可塑性变化的时程。结果术后不同时间段电刺激患爪正中神经支配区,在双侧Sml均未诱发出SEP。电刺激健侧前爪正中神经支配区,在健爪同侧Sml未记录到SEP,只在其对侧Sml记录到SEP；但不同时间段的SEP位点数目均明显多于正常对照组。结论成年大鼠的初级体感皮层仍具有可塑性,一侧全臂丛根性撕脱伤后诱发了双侧Sml动态的功能重组。两大脑半球相对应的同位区域之间存在着维持半球间平衡和协调的特殊机制。健侧前爪体感代表区的扩大可提高健爪的感觉辨别能力,以部分代偿患肢感觉功能的丧失。Objective To investigate the changes of plasticity of bilateral Sm1 at different intervals following total brachial plexus root avulsion injuries in adult rats. Methods Total left brachial plexus root avulsion injury model was set up in 25 male Sprague-Dawley rats. They were divided into 5 groups according to different intervals of examination, including 1 day, 7 days, 1 month, 3 months, and 1 year groups. Another 5 rats without surgery served as control. Somatosensory evoked potential （SEP） was used to quantitatively evaluate the changes of plasticity in bilateral Sm1. Results SEPs were not evoked from bilateral Sm1 when the median nerve region of theaffected forepaw was stimulated, neither were they evoked from ipsilateral Sm1 when the median nerve region of the unaffected forepaw was stimulated at different intervals following total left brachial plexus root avulsion injuries. On the contrary, SEPs were induced from contralateral Sm1 of the unaffected forepaw throughout the entire period following total left brachial plexus root avulsion injury. Meanwhile, sites number of the evoked SEPs at different intervals was much more than that of the control. Conclusion The Sm1 of adult rats still had the ability of plasticity. Dynamic functional reorganization took place in bilateral Sm1 of adult rats following total brachial plexus root avulsion injury of one forelimb. Special mechanism that maintains the balance and coordination between the corresponding homologous regions of bilateral cerebral cortex may exist. Enlargement of somatosensory cortex representation region of the intact forelimb might enhance its sensory discrimination ability in compensation for the sensory loss of affected forelimb.

关 键 词：臂丛 神经损伤 脊神经根 大脑皮层 神经元可塑性 功能重组 

分 类 号：R651.3[医药卫生—外科学] R338.3[医药卫生—临床医学]