SNARE蛋白及其调节因子在S284L-Chrna4转基因鼠癫痫发作机制中的作用

人类常染色体显性夜发性额叶癫痫(ADNFLE)的发病与烟碱型乙酰胆碱受体亚基的编码基因突变有关。申请者等此前已成功的开发了与ADNFLE具有同等变异基因背景的转基因动物模型(S284L-Chrna4转基因鼠)。初步研究表明S284L-Chrna4转基因鼠的癫痫发作与谷氨酸(glutamate)和GABA神经传递异常有关。为进一步阐明ADNFLE的发病机制，本课题拟利用S284L-Chrna4转基因鼠建立模拟人类癫痫疾患的动物模型平台，运用分子生物学、药理学等方法探究参与glutamate和GABA等神经递质释放机制的SNARE蛋白及其调节因子在癫痫发作机制中的作用。同时，本课题还将利用此动物模型平台探讨SNARE蛋白及其调节因子在抗癫痫药物的药理机制中的作用，为研制新型抗癫痫药物或开发新的治疗方法积累必要的基础学数据和奠定科学的理论基础。

It has been confirmed that exocytosis mechanism is responsible for neurotransmitter release, which is triggered by depolarization of the nerve terminal induced by an influx of Ca2+ through voltage-sensitive Ca2+ channels (VSCCs). The activation of some protien kinases by elevated Ca2+ can influence the assembly/disassembly of SNAREs (soluble N-ethylmaleimide-sensitive fusion factor attachment protein receptors), which mediate the docking of vesicles and exocytosis of neurotransmitter during synaptic transmission. Recently, several studies have revealed an ipsilateral hippocampal accumulation of SNARE complexes in kindling-induced epilepsy. Interestingly, studies showed that this accumulation of SNARE complexes was correlated with enhanced glutamate release, and reversed by antiepileptic drug. Moreover, expression changes of some regulators of SNAREs in hippocampus of kindled animals were also reported. In this light, SNAREs and its regulators may be involved in the epileptic mechanisms by influencing neurotransmitter releases. Recently, we have generated transgenic rats that bear transgenes with a rat Chrna4 missense S284L mutation, corresponding to a mutation identified in autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). The transgenic rats, free of biological and behavioral abnormalities, showed epileptic seizure phenotypes similar to those in human ADNFLE. We have found that the dysfunction of GABA and glutamate release may play a central role in the epileptic mechanisms of ADNFLE; however, the detailed mechanisms should be clarified. Therefore, to explore the epileptic mechanisms of ADNFLE and novel targeting mechanisms for the antiepileptic actions of antiepileptic drugs, we propose to analyze the expression and function changes of SNAREs and its regulators in different brain regions of S284L-Chrna4 transgenic rats.