兔骨骼肌运动点与运动终板的形态学研究及临床意义

目的:探索运动点的本质是终末神经纤维密集区,还是运动终板密集区,给化学神经阻断技术的定位方法提供理论依据。方法:成年新西兰兔9只,靶肌肉为双侧肱二头肌及双侧腘绳肌。每块肌肉选择2个研究点,共计72个点分为3组:小神经密集区(N组):通过最小电刺激引起最大收缩的部位;运动终板密集区(P组):肌电图显示终板电活动最活跃的部位;非密集区对照组(C组):以最强电流诱发最弱靶肌肉收缩,且连接肌电图后未出现终板电活动的部位;在以上部位注入染料定位。分别记录三组的电刺激强度。通过苏木精-伊红染色和乙酰胆碱酯酶染色,应用图文报告分析软件观察运动终板及神经纤维数量,将3组数据进行统计学分析。结果:电刺激强度比较:C组最大(0.73±0.05)mA,P组次之(0.39±0.04)mA,N组最小(0.10±0.01)mA,3组间两两比较均有显著差异(P<0.01)。神经纤维数量比较:N组最多,P组次之,C组最少。N组与P组之间的差异不显著(P>0.05),但N组与C组,P组与C组之间差异显著(P<0.01)。运动终板数量比较:P组最多,N组次之,C组最少,3组间两两比较差异均有显著性(P<0.05)。结论:终末神经纤维密集区和运动终板密集区十分接近,但是"运动点"概念不同。临床上可以使用电刺激技术作为肉毒毒素肌肉注射的定位技术。

Morphological study and clinical significance of skeletal muscle's motor end plates and motor points in rabbits

Objective:To characterize the morphology of motor points, i.e. whether they are compact district of nerve fiber or motor end-plate, and therefore to provide rationale for the localization methods during nerve blocking. Method:Nine New Zealand rabbits were used for the study. The musculus biceps brachii and hamstring bilaterally were selected as target muscles for injection. A total of 72 target points were divided into three groups:compact district of nerve fibers(Group N), where the maximal contraction was...