大鼠坐骨神经再生过程的条件损伤效应

EFFECT OF CONDITIONING LESION ON NERVE REGENERATION IN RATS

在大鼠腓神经伸趾长肌标本上,用微电极记录小终板电位(MEPP)和静息膜电位(RMP),观察腓神经损伤后的再生过程和条件损伤效应。结果表明:损伤后1～10d突触前递质自发释放完全消失,RMP幅度变小。到14d才出现频率慢波幅变宽的MEPP,30d仍未恢复正常,其频率和时程分别为正常的60％和169％。而RMP幅度仅为正常的84％。条件损伤组在损伤后30d MEPP的频率、时程和RMP幅度分别为正常时的78％、120％和97％,均比损伤对照组恢复快。说明条件损伤在运动神经的再生过程中可促进自发MEPP的出现和RMP的恢复。

Using method of intracellular recording miniature endplate potentials (MEPP) and resting membrane potentials (RMP), the axonal regeneration after a crush lesion, the testing lesion (TL), and the effect of conditioning lesion (CL) 16 days prior to TL were observed in preparation of peroneus nerve-extensor digitorum longus muscle of rats. The results showed that 1-10 days after TL, the presynaptic spontaneous transmitter release disappeared completely and RMP of the muscle fibers was reduced continuously. 14 days after TL, MEPP of low frequency and prolonged duration reappeared. RMP was partially restored. By 30 days after TL, the frequency and duration of MEPP still not returned to normal, being 60% and 169% of control respectively, and RMP was only 84% of control values. In CL group, MEPP reappeared on 10th day after TL, being earlier than TL alone. In the following days its frequency and duration and RMP recovered quickly, being about 78%, 120% and 97% of control respectively on 30th day after TL. It is considered that CL can accelerate spontaneous MEPP reappearance and RMP restoration during axonal regeneration.