Fast endocytosis is inhibited by GABA-mediated chloride influx at a presynaptic terminal
Fast endocytosis is inhibited by GABA-mediated chloride influx at a presynaptic terminal
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DOI：
10.1016/j.neuron.2004.10.010
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发表时间：
2004-10-28
期刊：
影响因子：
16.2
通讯作者：
von Gersdorff, H
中科院分区：
文献类型：
--
作者：
Hull, C;von Gersdorff, H
虽然突触囊泡内吞作用的多种动力学成分已被确定，但尚不清楚神经元是否可以不同地调节这些成分。利用分离的金鱼双极细胞末端的膜电容测量，我们发现视网膜片的内吞动力学（单指数衰减，tau bbb10 s）明显慢于急性解离末端(双指数衰减，tau（快速）接近1-2 s；Tau（慢）bbb10 s)。令人惊讶的是，GABA(A)和/或GABA(C)受体拮抗剂恢复了视网膜片末端的快速内吞作用成分。阻断来自相互突触的gaba能反馈或去除外部Cl离子也允许快速内吞。通过膜片移液管提高内部Cl-总是减缓内吞作用，甚至在终末透析增加Ca2+缓冲液。这些结果提示GABA和Cl离子在阻断这种带状突触快速胞吞的触发机制中具有新的作用。
Although multiple kinetic components of synaptic vesicle endocytosis have been identified, it has remained unclear whether neurons can differentially modulate these components. Using membrane capacitance measurements from isolated goldfish bipolar cell terminals, we found that the kinetics of endocytosis in retinal slices (single exponential decay; tau > 10 s) were significantly slower than those in acutely dissociated terminals (double exponential decay; tau(fast) approximate to 1-2 s; tau(slow) > 10 s). Surprisingly, GABA(A) and/or GABA(C) receptor antagonists restored the fast component of endocytosis to terminals in retinal slices. Blocking GABAergic feedback from reciprocal synapses or removing external Cl- ions also allowed for fast endocytosis. Elevating internal Cl- via the patch pipette invariably slowed endocytosis, even in terminals dialyzed with increased Ca2+ buffer. These results suggest a new role for GABA and Cl- ions in blocking the trigger for fast enclocytosis at this ribbon-type synapse.