Continuous and Transient Vesicle Cycling at a Ribbon Synapse
Continuous and Transient Vesicle Cycling at a Ribbon Synapse
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DOI：
10.1523/jneurosci.18-21-08614.1998
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发表时间：
1998-11
期刊：
影响因子：
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通讯作者：
N. Rouze;E. A. Schwartz
中科院分区：
文献类型：
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作者：
N. Rouze;E. A. Schwartz
用光学方法研究了金鱼视网膜双极细胞囊泡循环的Ca ~（2+）依赖性。将Ca 2+浓度均匀地提高到0.8 - 20 μm，产生了一个平衡的胞吐和胞吞的连续囊泡循环，其最大速率相当于每2分钟（或每秒1000个囊泡）的整个末端表面膜的周转。当Ca ~（2+）浓度超过20 μ m时，囊泡的连续循环受到抑制。相反，通过电压门控通道的Ca 2+内流产生胞吐的瞬时爆发，其最大增加了12%的末端表面积（相当于增加了13，000个囊泡）。胞吞作用延迟至Ca 2+内流停止后，终末平均Ca 2+浓度下降。因此，单个末端具有连续和瞬时囊泡循环的机制。
Optical methods were used to study the Ca2+dependence of vesicle cycling in bipolar cells isolated from goldfish retinas. Uniformly raising the Ca2+ concentration to between 0.8 and 20 μm produced a continuous vesicle cycle of balanced exocytosis and endocytosis with a maximum rate equivalent to the turnover of the entire surface membrane of a terminal every 2 min (or ∼900 vesicles sec−1). Increasing the Ca2+ concentration above 20 μminhibited continuous vesicle cycling. In contrast, influx of Ca2+ through voltage-gated channels produced a transient burst of exocytosis that increased the surface area of a terminal by a maximum of 12% (equivalent to the addition of 13,000 vesicles). Endocytosis was delayed until after Ca2+influx stopped and the average Ca2+ concentration in the terminal declined. Hence, a single terminal has mechanisms for both continuous and transient vesicle cycling.