氯化锂-匹罗卡品致痫大鼠海马EphA5及ephrinA3的表达及意义

目的探讨颞叶癫痫发作后海马EphA5及ephrinA3基因的表达变化和轴突出芽的关系。方法建立氯化锂-匹罗卡品颞叶癫痫大鼠模型,利用原位杂交方法检测致痫后12h、24h、7d、15d、30d、60d海马CA3区、CA1区EphA5及ephrinA3 mRNA的表达,快速Golgi染色观察CA1区的轴突出芽。结果致痫后,EphA5 mRNA在CA3区表达下调,ephrinA3 mRNA在CA1区表达下调,均在7d降至最低点,与对照组相比差异有显著意义(P<0.01),此后逐渐回升,但15d时仍低于对照组(P<0.05),在30d和60d与对照组相比差异无统计学意义(P>0.05)。快速Golgi染色显示,对照组大鼠CA1区轴突走行正常,匹罗卡品致大鼠SE后7dCA1区锥体细胞层出现显著增多的轴突染色。结论CA3区的EphA5和CA1区的ephrinA3的表达下调可能与CA1区的轴突出芽、突触重建有关。

Expression and its significance of EphA5 and ephrinA3 mRNA in the rat hippocampus after epilepsy induced by lithium pilocarpine

Objective To explore the expression and significance of EphA5 and ephrinA3 mRNA in the rat hippocampus after epilepsy induced by lithium pilocarpine.Methods By use of in situ hybridization and image analysis,the EphA5 ephrinA3 mRNA were analyzed at different time quantitatively in the CA1/CA3 regions of hippocampus.Other axonal sprouting were observed with fast Golgi stain.Results EphA5 mRNA was existed in the dentate granule cell and every subfield of hippocampus,EphA5 mRNA reduced remarkably(P<0.01=in CA3 regions on 7d after pilocarpine-induced.On 30d,there were no diffent in EphA5 mRNA expression between test and control(P>0.05).In CA1 regions,EphA5 mRNA had no changes at every time point(P>0.05).EphrinA3 mRNA expressed extensive in dentate gyrus and CA3/CA1 regions of hippocampus.On 7d after pilocarpine-induced,EphrinA3 mRNA reduced remarkably(P<0.01)in CA3 and CA1 regions,specifically in CA1 regions.On 30d,it returned normal control levels(P>0.05).The appeased of axons in CA1 was normal.Axon staining was significantly increased in CA1 pyramidal layer rats on 7d after with fast Golgi stain.Conclusion The axon sprouting and synaptic reorganization in CA1 region maybe correlate with the down-regulation of EphA5 mRNA in CA3 region and ephrinA3 mRNA in CA1 region after SE