褪黑素对匹罗卡品致癫癎大鼠海马神经发生和突触重建的影响

目的探讨褪黑素(Mel)在匹罗卡品(PILO)致癫癎犬鼠模型中的抗癫癎作用机制。方法将45只Wistar大鼠按癫癎持续状态(SE)后6 h,14、28天分为PILO组(1 5只),PILO+Mel组(15只)和对照组(15只),采用PILO诱导大鼠慢性颞叶癫癎模型,用5溴-2-脱氧尿嘧啶核苷标记增殖细胞,Timms染色评价苔藓纤维发芽(MFS)等技术,动态观察MeI对癫癎大鼠海马神经发生和MFS的影响及其与反复自发性癫癎发作(SRS)发生的关系。结果与对照组比较,PILO组大鼠SE后6 h,14、28天细胞数明显增加,差异有统计学意义(P<0.01);与PILO组比较,PILO+Mel组大鼠在SE后6 h,14、28天,细胞数量明显减少(P<0.05),28天SRS数量明显减少,差异有统计学意义(P<0.05)。与PILO+Mel组比较,PILO组大鼠SE后14天,Timms染色密度开始增强,28天密度明显增强,差异有统计学意义(P<0.05)。结论Mel对SRS的预防作用可能与其对癫癎诱导的神经发生和MFS的抑制作用有关。

Effect of melatonin on neurogenesis and synaptic reorganization in hippocampus of epileptic rats induced by pilocarpine

Objective To probe the mechanism of anticonvulsant effect of melatonin(Mel).Methods Model of epilepsy induced by pilocarpine(PILO) was used.The proliferating cells were labeled by 5-bromo-2'-deoxyuridine(BrdU),and the mossy fiber sprouting(MFS) was evaluated by Timm staining.The effects of melatonin on neurogenesis,MFS and spontaneous recurrent epileptic seizure(SRS) in hippocampus of epileptic rats induced by pilocarpine were observed.Results The BrdU-labeled cells increased significantly in PILO group at 6 h and on 14 and 28 d post-status epilepticus(SE) and were significantly more than in control group(P<0.01).The BrdU-labeled cells were significantly less in PILO+Mel group than in PILO group(P<0.05).The intensity of supragranular MFS began to increase in PILO group on d 14 post-SE.On d 28 post-SE,the intensity of supragranular MFS in PILO group was significantly higher compared with PILO+Mel group(P<0.05).The number of SRS was significantly lower in PILO+Mel group than in PILO group during the observing period(P<0.05).Conclusion Anticonvulsant effect of melatonin may be due to its ability to inhibiting neurogenesis and MFS in hippocampus of epileptic rats.