癫痫状态大鼠海马GABA、GABA_A受体α5亚单位表达的动态变化

Dynamic changes of GABA and GABA_A receptor α5 expressions in hippocampus of rats in status epilepticus induced by pilocarpine

目的探讨γ-氨基丁酸(γ-aminobutyricacid,GABA)及GABAA受体α5亚单位在癫痫持续状态(statusepi-lepticus,SE)大鼠海马中的变化规律及其与自发反复性癫痫发作(spontaneousrecurrentepilepticseizure,SRS)的关系。方法采用匹罗卡品诱导大鼠SE模型,用免疫组化技术检测大鼠SE后4个时相点即6、48、72h和7d海马GABA和GABA_A受体α5亚单位表达的动态变化。结果PILO组大鼠SE后6h至7d,海马内GABA能神经元持续减少,尤其以SE后48h至7d改变最为明显,并与对照组比较差异极显著(P<0.01);SE后6h,PILO组大鼠海马GABA_A受体α5亚单位的表达开始下降,SE后72h至7d,GABA_A受体α5亚单位的表达显著降低,并明显低于对照组(P<0.01)。结论GA-BA及GABA_A受体Rα5亚单位表达的下调可能是SRS产生的重要因素之一。

Objective To probe the expressions of γ-aminobutyric acid（GABA） and GABAA receptor α5 subunit in the hippocampus of rats with status epilepticus （SE） to explore the relationship between the changes and the genesis of spontaneous recurrent epileptic seizure （SRS）. Methods Rat model of SE was induced by pilocarpine （PILO）. Expressions of GABA and GABAA receptor α5 subunit in the hippocampus was observed by immunocytochemistry at 6, 48, 72, 7 d after SE. Results The GABA-immunoreactivity （GABA-IR） neurons continued to decrease in PILO group at 6 h to 7 d post-SE. The GABA-IR neurons were significantly lower in PILO group than in control group at 48 h to 7 d post-SE. The expression of GABAAR α5 subunit was decreased in PILO group at 6 h post-SE, and significantly lower than that of control group fran 72 h to 7 d postSE. Conclusion Down-regulation of GABA and GABAA receptor α5 subunit expressions may play an important role in the genesis of SRS.