[ Eph在慢性颞叶癫痫大鼠齿状回苔藓纤维轴突发芽机制中的作用]

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

作者信息

Liu Wei-ping, Xiao Bo, Li Shu-yu, Lu Xiao-qin

机构信息

Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, China.

出版信息

Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2008 Aug;33(8):657-62.

PMID:18772502

Abstract

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.

摘要

目的

探讨毛果芸香碱诱导的慢性颞叶癫痫大鼠齿状回中苔藓纤维轴突发芽（MFS）、突触重组以及Eph A5和ephrin A3表达改变之间的关系。

方法

在氯化锂和毛果芸香碱诱导急性癫痫持续状态和慢性自发性颞叶癫痫后，通过改良的Timm染色观察大鼠苔藓纤维发芽和突触形成情况。采用原位杂交检测ephrin A3 mRNA，应用免疫组织化学染色检测Eph A5蛋白。

结果

在内嗅皮质，仅表达Eph A5 mRNA和蛋白；在毛果芸香碱诱导癫痫持续状态后第7天，二者显著降低（P<0.01），并在第30天恢复至正常水平（P>0.05）。在齿状颗粒细胞中，毛果芸香碱诱导癫痫持续状态后第7天，ephrin A3 mRNA明显降低（P<0.01），并在第30天恢复至正常水平（P>0.05）。