Basarsky T A, Parpura V, Haydon P G
Signal Transduction Training Group, Iowa State University, Ames 50011-3223.
J Neurosci. 1994 Nov;14(11 Pt 1):6402-11. doi: 10.1523/JNEUROSCI.14-11-06402.1994.
The formation of chemical synapses between hippocampal neurons in primary cell culture was studied using electrophysiology, calcium imaging, and immunocytochemical approaches. Inhibitory and excitatory synapses formed within 12 d in cell culture (DIC) that were sensitive to the N-type calcium channel blocker omega-conotoxin GVIA (omega-CgTx). At 4 DIC, immature connections were present in which spontaneous, but rarely evoked, synaptic currents were detected. At both 4 and 12 DIC, the synaptic proteins rab3a, synapsin I, and synaptotagmin were present in hippocampal neurons, but the subcellular distribution changed from one in which immunoreactivity was initially distributed within soma and neurites to a punctate varicose appearance. Correlated with the transformation from immature to mature synaptic states was the onset of omega-CgTx-sensitive calcium influx. Taken together, these data suggest that the expression of functional omega-CgTx-sensitive calcium influx is temporally coincident with synapse formation, and that during the maturation of the synapse there is a redistribution of synaptic proteins.
利用电生理学、钙成像和免疫细胞化学方法，研究了原代细胞培养中海马神经元之间化学突触的形成。抑制性和兴奋性突触在细胞培养12天（体外培养天数）内形成，且对N型钙通道阻滞剂ω-芋螺毒素GVIA（ω-CgTx）敏感。在体外培养4天时，存在未成熟连接，其中检测到自发但很少诱发的突触电流。在体外培养4天和12天时，海马神经元中均存在突触蛋白rab3a、突触素I和突触结合蛋白，但亚细胞分布从最初免疫反应性分布于胞体和神经突内的状态转变为点状静脉曲张样外观。与从未成熟突触状态向成熟突触状态的转变相关的是ω-CgTx敏感的钙内流的开始。综上所述，这些数据表明，功能性ω-CgTx敏感的钙内流的表达在时间上与突触形成一致，并且在突触成熟过程中存在突触蛋白的重新分布。
