Molecular identity, synaptic localization, and physiology of calcium channels in retinal bipolar cells
Molecular identity, synaptic localization, and physiology of calcium channels in retinal bipolar cells
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DOI：
10.1002/jnr.10459
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发表时间：
2003-01-01
影响因子：
4.2
通讯作者：
Morgans, CW
中科院分区：
文献类型：
--
作者：
Berntson, A;Taylor, WR;Morgans, CW
双极细胞通过膜电位的渐进性变化通过视网膜传递信息，并通过L类型的钙通道调节钙离子的内流来调节递质释放。然而，α亚基的分子同源性尚未得到证实。我们报道了新克隆的α(1F)亚单位在小鼠双极细胞突触终末的存在。α(1F)亚基定位于热点，可能对应于活动区。我们还报道了小鼠双极细胞中存在的两种钙电流的生理特性，一种是低电压激活的L型电流，另一种是低电压激活的T型钙电流。T-型电流的生理特性表明，它在生理条件下完全失活。L型电流可能由α(1F)亚单位介导，而钙离子通过α(1F)通道的内流可能控制双极细胞终末的神经递质释放。(C)2002年Willey-Liss公司
Bipolar cells convey information through the retina via graded changes in their membrane potential and modulate transmitter release through the influx of calcium via L-type calcium channels. However, the molecular identity of the a, subunit has not been confirmed. We report the presence of the newly cloned alpha(1F) subunit in mouse bipolar cell synaptic terminals. The alpha(1F) subunits are localized to hot spots, possibly corresponding to active zones. We also report the physiological properties of two calcium currents present in mouse bipolar cells, a low-voltage-activated L-type current and a low-voltage-activated T-type calcium cur-rent. The physiological properties of the T-type current suggest that it is completely inactivated under physiological conditions. The L-type current may be mediated by the alpha(1F) subunit, and influx of calcium through the alpha(1F) channel may control neurotransmitter release from the bipolar cell terminal. (C) 2002 willey-Liss, Inc.