Ca2+-dependent exocytosis in the somata of dorsal root ganglion neurons
Ca2+-dependent exocytosis in the somata of dorsal root ganglion neurons
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DOI：
10.1016/s0896-6273(00)80287-1
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发表时间：
1996-07-01
期刊：
影响因子：
16.2
通讯作者：
Neher, E
中科院分区：
文献类型：
--
作者：
Huang, LYM;Neher, E
使用电容测量和单细胞免疫印迹分析研究在背根神经节神经元的分泌，我们发现，胞体经历了强大的胞吐后去极化和释放P物质，在响应KCl刺激。不同膜电位下电容响应与胞内Ca ~（2+）浓度（[Ca ~（2+）]（i））的平行变化以及Ca ~（2+）螯合剂对胞吐的抑制表明索马体释放是Ca ~（2+）依赖性的。我们还通过用Ca 2+离子载体离子霉素提高平均[Ca 2 +]（i）来评估胞吐所需的Ca 2+水平。电容变化由细胞质Ca 2 + > 0.6 μ M触发;去极化期间释放位点的[Ca 2 +]（i）估计为3-10 μ M。这些Ca 2+水平与从神经内分泌细胞获得的水平相似，但比从神经末梢释放递质所需的水平低至少10倍。
Using capacitance measurements and the single-cell immunoblot assay to study secretion in dorsal root ganglion neurons, we found that the somata underwent robust exocytosis upon depolarization and released substance P, in response to KCI stimulation. The parallel changes between capacitance responses and intracellular Ca2+ concentration ([Ca2+](i)) at different membrane potentials and the inhibition of exocytosis by Ca2+ chelators suggest that soma release is Ca2+-dependent. We also assessed the level of Ca2+ required for exocytosis by raising the average [Ca2+](i) with the Ca2+ ionophore, ionomycin. Capacitance changes were triggered by cytosolic Ca2+ > 0.6 mu M; the [Ca2+](i) at the release sites during depolarizations was estimated to be 3-10 mu M. These Ca2+ levels are similar to those obtained from neuroendocrine cells, but are at least 10 times lower than those required for transmitter release from nerve terminals.