电惊厥及电刺激耳大神经抗惊厥时大鼠海马生长抑素的变化

本工作选用电惊厥大鼠为实验性癫痫模型，观察了电刺激耳大神经对大鼠电惊厥发作的影响，结果表明：电刺激耳大神经能抑制电惊厥诱导的大脑皮层痫样放电，并可以明显缓解惊厥症状。应用免疫组织化学和原位杂交方法观察了电惊厥及电刺激耳大神经抗惊厥后海马神经元生长抑素及其mRNA的变化。结果显示：电惊厥时海马CA4区、下托处生长抑素免疫反应明显减弱，生长抑素mRNA表达显著增高；电刺激耳大神经抗惊厥后，CA4区，下托处生长抑素免疫反应明显增强。生长抑素mRNA表达显著下降。提示：电惊厥时海马生长抑素释放增加，生长抑素基因表达增强，生长抑素的合成增加；电刺激耳大神经抗惊厥后海马生长抑素释放减少，生长抑素基因表达下降，生长抑素的合成减少；电刺激耳大神经对电惊厥的抑制作用与其在海马调控生长抑素基因的表达有关。

CHANGES OF SOMATOSTATIN IN THE HIPPOCAMPUS FOLLOWING ELECTROCONVULSION AND THE ANTIOCONVULSION EFFECT CAUSED BY GREAT AURICULAR NERVE ELECTROSTIMULATION

Electroconvulsion (ECS) was chosen as a model of experimental epilepsy. The antiepileptic effects of the great auricular nerve electrostimulation (GANE) was observed by electrophysiological technique. The results showed that GANE significantly decreased amplitude and frequency of epileptiform spikes, and effectively inhibited convulsion induced by ECS. Changes of somatostatin-immunoreactive (SS-IR) and SSmRNA in the hippocampal neurons following ECS and GANE antioconvulsion were also observed by immunohistochemical technique, in situ hybridization and micro-image analyser (Leica Q570). The results indicated that in CA4 area and subiculum, ECS significantyl decreased SSIR and enhanced the expression of SSmRNA, while GANE antioconvulsion significantly increased SSIR and inibited the expression of SSmRNA These findings suggest that SS release and synthesis increase foolowing ECS, and decrease following GANE antioconvulsion. The inhibitory effects of GANE on ECS is likely to be relevant to GANE regulating expression of somatostatin gene in hippocampus.