不同年龄大鼠神经再生趋化性差异的研究

目的 比较不同年龄大鼠坐骨神经切断后，其神经再生趋化性在组织持异性和解剖特异性水平上的差异。方法 大鼠按年龄分幼年和成年组各40只，分别建立组织特异性(幼、成年组各20只)和解剖特异性(幼、成年组各20只)模型，术后3、6周分别采用神经电图、组织学检测神经再生。结果 术后3、6N，幼年组在神经传导速度恢复率、神经纤维再生准确率、胫腓神经传导速度比值和波幅比值、远端胫神经侧与腓总神经侧有髓轴索数的比值方面均低于成年组；但复合肌肉动作电位波幅恢复率两组无显著差异。结论 幼年大鼠周围神经再生趋化性的组织和解剖特异性较成年差，提示幼年大鼠较易发生主动肌与拮抗肌同步收缩的主要原因在于周围神经的错向生长。

Comparison of chemotaxis during the peripheral nerve regeneration in rats of different ages

Objective To compare the differences of chemotaxis at the tissue specific level and topographic specificity level during peripheral nerve regeneration after the severance injury of the sciatic nerve in rats of different ages. Methods 40 specific pathogen free Sprague Dawley 18 day old rats (called as young group) were chosen to correspond as nearly as possible to humans of about 1 year of age. 40 adult rats (called as adult group) were chosen to correspond as adult humans. The tissue and topographic specificity models were set up respectively after the severance of the sciatic nerve at the right side. Electromyography and morphological evaluations were conducted for determination of the nerve regeneration on 3 and 6 weeks postoperatively. Results On 3 and 6 weeks after operation, the recovery rate of nerve conduction velocity, the exact rate of nerve regeneration, the ratio of nerve conduction velocity between tibial and peroneal nerve, the ratio of amplitude of CMAP between tibial and peroneal nerve, the ratio of the number of myelinated axon between the tibial and peroneal nerve at the distal part in the young group were lower than those in the adult group respectively. There were statistically significant differences between the 2 groups. The recovery rate of amplitude in compound muscle action potential (CMAP) was lower in the young group than in the adult group, but the difference was not significant enough. Conclusion Since the tissue and topographic specificities in the young rats are both inferior to those in the adult rats, co contraction between agonists and antagonists may result from cross innervation during the peripheral nerve regeneration.