戊四氮点燃过程中大鼠海马苔藓纤维发芽变化的研究

目的 :探讨戊四氮 (PTZ)诱导点燃过程中大鼠海马细胞形态的可塑性与慢性癫痫发病机制的关系。方法 :450只大鼠随机分为对照组、药物组 (PTZ 3 5mg/kg腹腔注射 ,每天 1次 )和干预组 (苯巴比妥 3 0mg/kg及PTZ 3 5mg/kg腹腔注射 ,每天 1次 ) ,诱导大鼠点燃过程中采用Timm银染组织化学方法观察海马区苔藓纤维出芽。并分析 3组间苔藓纤维出芽的差异。结果 :药物组大鼠注射PTZ后 ,行为学未出现惊厥 ,脑电图未出现癫痫性放电的点燃前潜伏期内 ,在海马齿状回内分子层和CA3区透明层出现异常苔藓纤维出芽 ,与对照组比较 ,差异有显著性 (P <0 .0 5) ,与干预组对应时间点比较 ,差异亦有显著性 (P <0 .0 5)。结论 :苔藓纤维出芽 海马细胞形态的可塑性是PTZ点燃大鼠慢性癫痫形成的重要机制 ,苯巴比妥可能通过抑制苔藓纤维出芽 ,预防癫痫发生。

Investigation on the Variation of the Mossy Fiber Sprouting in Hippocampus of Pentylenetrazol Kindling Rats

Objective: To investigate the relationship b etween the plasticity of cell modality in murine hippocampus and the pathogenesi s of chronic epilepsy during the pentylenetrazol (PTZ) kindling process. Methods : 450 rats were randomly divided into 3 groups: control group, PTZ-treated gro up (PTZ 35 mg/kg, intraperitoneal injection, once every day) and intervention gr oup (phenobarbital 30 mg/kg and PTZ 35 mg/kg, intraperitoneal injection, once ev ery day). The mossy fiber sprouting in hippocampus during the kindling process w as observed by Timm silver staining and the difference among the 3 groups was an alyzed. Results:During the latent period of PTZ-kindling before the occurrence of convulsion confirmed by behavior and EEG, abnormal mossy fiber sprouting was observed in the inner molecular layer of the dentate gyrus and the transparent layer of CA3 section of the hippocampus in PTZ-treated group. There were signif icant difference between PTZ-treated group and control group or intervention gr oup at the corresponding time points (all P <0.05). Conclusion: Mossy fiber sprouting and plasticity of cell modality in hippocampus may play an important r ole in the pathogenesis of chronic epilepsy in PTZ Kindling rats. PTZ probably c an interfere with this epileptogenesis by inhibiting the mossy fiber sprouting i n hippocampus.