中文摘要：

目的：研究大鼠成熟与发育过程中坐骨神经髓鞘形态与功能的改变。方法：利用透射电镜观察不同年龄阶段大鼠（1周、1、3、9、15、21月）坐骨神经横切面的髓鞘形态,计数髓鞘板层;采用电生理学检测大鼠坐骨神经复合肌动作电位,记录其潜伏期及振幅,计算神经传导速度,并分析与髓鞘板层数之间的相关性。结果：髓鞘层数从1周到15个月逐渐增加,21个月时没有显著变化;神经传导速度9个月时达到峰值,以后随年龄的增加逐渐下降,3个月时复合肌动作电位振幅达到最大,潜伏期最短,后随年龄的增长振幅降低,潜伏期延长,并且神经传导速度、振幅、潜伏期与髓鞘板层数之间不呈线性相关。结论：大鼠坐骨神经髓鞘板层及电生理功能在成熟与发育过程中发生改变,且两者变化之间不呈直线相关。

英文摘要：

Objective： To investigate the morphological and functional changes in myelin of rat sciatic nerves during the maturation and aging process.Methods： The morphology of myelin of sciatic nerves was observed by electron microscope in rats from 1 week to 21 months of age and the number of myelin sheath lamellae was counted.The compound muscle action potentials（CMAPs） of sciatic nerves were recorded by electrophysiological examinations and the latency and amplitude of CMAPs,as well as nerve conduction velocity（NCV） were calculated.Results： The number of myelin sheath lamellae gradually increased from 1 week to 15 months of age,and then remained nearly unchanged until 21 months of age.NCV increased from 1 month to 9 months of age,when it reached the peak value,and then gradually slowed down.The amplitude of CMAPs reached the peak value at 3 months and then declined.The latency of CMAPs gradually increased with age.NCV,the amplitude and latency of CMAPs displayed nonlinear correlation with the number of myelin sheath lamellae.Conclusion： The results showed that the myelin sheath and electrophysiological features of rat sciatic nerves changed during the maturation and aging process and there was nonlinear correlation between them.