Eph在颞叶癫痫大鼠齿状回苔藓纤维出芽机制中的作用  

Eph in the mechanism of mossy fiber axon sprouting in dentate gyrus in rats with chronic temporal lobe epilepsy

作　　者：刘卫平[1] 肖波[1] 李蜀渝[1] 卢晓琴[1] 

机构地区：[1]中南大学湘雅医院神经内科,长沙410008

出　　处：《中南大学学报（医学版）》2008年第8期657-662,共6页Journal of Central South University ：Medical Science

基　　金：卫生部临床学科重点计划项目(卫规财函[2007]353号);湖南省科技厅计划项目(2007TP4005)~~

摘　　要：目的:探讨匹罗卡品致痫大鼠Eph A5和ephrin A3在海马齿状回的表达变化与苔藓纤维出芽和突触重建的关系。方法:急性诱导癫痫持续状态及慢性颞叶癫痫形成后,采用Neo-Timm银染观察苔藓纤维出芽及突触重建,并用原位杂交方法检测ephrin A3基因的动态变化,用免疫组织化学方法检测Eph A5蛋白的动态变化。结果:在内嗅皮质区(EC)仅有Eph A5的表达,致痫后第7天,Eph A5的表达下调,降至最低点(P<0.01),此后逐渐回升,但第15天时仍低于对照组(P<0.05),第30天时回归至对照组水平(P>0.05)。在齿状回(DG),Eph A5及ephrin A3在致痫后第7天明显较对照组降低(P<0.01),此后逐渐回升,但第15天时仍低于对照组,在第30天和第60天与对照组相比无统计学差异(P>0.05)。结论:内嗅皮质区EphA5和齿状回Eph A5及ephrin A3的表达下调可能是癫痫持续状态(SE)后苔藓纤维出芽至齿状回内分子层的分子学机制之一。Objective To investigate the relationship among mossy fiber axon sprouting （MFS） , synaptic reorganization, and the alteration of expression of Eph A5 and ephrin A3 in the dentate gyrus in rats with pilocarpine-induced chronic temporal lobe epilepsy. Methods Mossy fiber sprouting and synaptic formation in rats were observed by Neo-Timm staining, after the acute status epilepticus and chronic spontaneous temporal lobe epilepsy induced by lithium-chloride and pilocarpine. In situ hybridization was used to detect ephrin A3 mRNA and an immunohistochemical staining was applied to determine Eph A5 protein. Results In entorhinal cortex, only Eph A5 mRNA and protein expressed, which significantly decreased on Day 7 after pilocarpine induced status epilepticus （P〈0.01） , and resumed to normal levels on Day 30 （P〉0.05）. In the dentate granule cells, Ephrin A3 mRNA reduced obviously on Day 7 after pilocarpine-induced status epilepticus （P〈0.01） , and returned to normal levels on Day 30 （P〉0.05）. Conclusion The down-regulation of Eph A5 mRNA and protein in entorhinal cortex and dentate gyrus,and ephrin A3 mRNA in dentate gyrus after status epilepticus may be part of the endogenous molecular mechanism of mossy fiber sprouting to the inner molecular layer of dentate gyrus.

关 键 词：EPH A5 EPHRIN A3 苔藓纤维出芽 突触重建 

分 类 号：R742.1[医药卫生—神经病学与精神病学]