牵拉损伤对蛙坐骨神经干动作电位影响的定量研究

Quantitative study on the effect of traction injury on the action potential of the sciatic nerve trunk in frogs

目的:探讨牵拉损伤对蛙坐骨神经干动作电位的影响。方法:建立一种简便、可量化的神经牵拉损伤模型,将60只牛蛙的120根坐骨神经随机分为12组,每组10根,区分左右坐骨神经。对照组不牵拉,实验组分别以0.1、0.2、0.3、0.4、0.8、1.2、1.6、2.0、2.4、2.8、3.2 N的拉力牵拉后测量坐骨神经的动作电位幅度、绝对不应期、传导速度和刺激阈值,比较不同牵拉程度对蛙坐骨神经动作电位的影响。结果:蛙坐骨神经干在2.8 N以下的牵拉力作用下可保持形态完整,3.2 N牵拉力则可使神经干发生断裂。随着牵拉力的增大,坐骨神经动作电位幅度及传导速度逐渐减少(P值均<0.05),2.4、2.8 N处理组的绝对不应期延长(P值均<0.05)。除了2.8 N处理组,其他组动作电位的刺激阈值与对照组相比差异无统计学意义(P值均>0.05)。结论:蛙坐骨神经干动作电位的传导速度对牵拉损伤最敏感,而刺激阈值和绝对不应期对牵拉损伤的耐受程度较高。

Objective:To investigate the effect of traction injury on the action potential of the sciatic nerve trunk in frogs.Methods:A simple and quantifiable model of nerve traction injury was established,and 60 bullfrogs with a total of 120 sciatic nerves were randomly divided into 12 groups of 10 nerves each,distinguishing between left and right.The control group was not stretched,and the experimental group was stretched with 0.1,0.2,0.3,0.4,0.8,1.2,1.6,2.0,2.4,2.8,3.2 N.The action potential amplitude,the absolute refractory period,the conduction velocity and the stimulus threshold of the sciatic nerve were measured after stretched with different degrees of traction,and the effects of different degrees of traction on the action potential of the frog sciatic nerve were compared.Results:The sciatic nerve trunk of frogs could maintain its morphological integrity under the traction force of less than 2.8 N,while the nerve trunk could be ruptured under the traction force of 3.2 N.With the increase of traction force,the amplitude of action potential and conduction velocity of sciatic nerve gradually decreased(all P<0.05),and the absolute refractory period of 2.4 and 2.8 N treatment groups was prolonged(all P<0.05).Except for the 2.8 N treatment group,there was no statistically significant difference in the stimulation thresholds of action potentials in the other groups compared with the control group(all P>0.05).Conclusion:The conduction velocity of the action potential of the sciatic nerve trunk of frogs is the most sensitive to traction injury,while the stimulation threshold and absolute refractory period are highly tolerant to traction injury.