The mechanism of neurotransmitter release and its control using electric organ synapse of electric ray

1.从电离辐射中克隆大鼠运动神经元电压依赖性钙通道的基因片段。获得了N型和L型电压依赖性钙通道的部分序列。建立了研究电器官神经末梢钙通道电生理特性的实验装置。为了研究电器官突触体钙通道的电生理特性，引入了脂质双层系统，初步实验表明，在Teterahymens的纤毛膜泡中检测到一种电压依赖性的阴离子通道。突触体膜磷脂在突触体膜和突触囊泡中的非对称性分布。在两种膜中，面对细胞质的小叶中以磷脂酰丝氨酸(PS)为主。研究腺苷对电子器官突触体释放乙酰胆碱的影响。腺苷通过腺苷A1受体抑制ACh的释放，通过A2受体促进ACh的释放。通过A1受体的抑制作用是通过N型电压依赖性钙通道的抑制，而通过A2受体的易化作用是由P型钙通道的激活引起的。

1. cDNA cloning of voltage-dependent Ca channel of electromotor neuron from electric ray.RT-PCR was carried out with electric lobe of Japanese electric ray, Narke Japonica. Partial sequence of N- and L-type voltage dependent Ca channel were obtained.2. Experimental setup to investigate the electrophysiological characteristics of Ca channel of electric organ nerve terminal.In order to do the electrophysiological characterization of Ca channel of electric organ synaptosomes, lipid bilayer system was introduced.Preliminary experiments revealed that a voltage dependent anion channel was detected in ciliary membrane vesicles from Teterahymena.3. Asymmetrical distribution of phospholipids in membrane of synaptosome and synaptic vesicle from electric ray.The asymmetrical distribution of phospholipids between the outer and inner leaflets of synaptosome and synaptic vesicle was investigated. In both membranes, phosphatidylserine (PS) was dominant in the leaflet which faces cytoplasm.4. The effects of adenosine on the acetylcholine release from electric organ synaptosomes.The effects of adenosine on the acetylcholine (ACh) release from synaptosomes was investigated. Adenosine inhibited the ACh release through adenosine Al receptor and facilitated the release through A2 receptor. The inhibitory effect via Al receptor was caused by the inhibition of N-type voltage dependent Ca channel, and the facilitatory effects via A2 receptor was caused by the activation of P-type Ca channel.