REAL-TIME MEASUREMENT OF TRANSMITTER RELEASE FROM SINGLE SYNAPTIC VESICLES
REAL-TIME MEASUREMENT OF TRANSMITTER RELEASE FROM SINGLE SYNAPTIC VESICLES
复制标题
DOI：
10.1038/377062a0
复制
发表时间：
1995-09-07
期刊：
影响因子：
64.8
通讯作者：
JAHN, R
中科院分区：
文献类型：
--
作者：
BRUNS, D;JAHN, R
神经递质的释放是由突触囊泡的Ca 2+依赖性胞吐作用介导的，从单个突触囊泡释放的递质的量和该过程的动力学都还没有被直接确定。使用碳纤维作为电化学检测器（2，3），我们测量了从水蛭的培养神经元释放的神经递质5-羟色胺（4）。这种技术使我们能够以高时间分辨率监测单个突触囊泡的递质放电，作为尖峰样氧化电流，为神经元胞吐作用的机制提供了新的见解。表征了两种类型的信号，对应于这些细胞中存在的小的透明和大的致密核心囊泡的胞吐作用。小囊泡放电约4，700个传递分子，时间常数在260 μ s范围内，而大囊泡释放其内容物约80，000个分子，时间常数约为1.3 ms，两种囊泡类型的释放都迅速启动，上升时间小于60 μ s，表明预组装的融合孔突然打开。
NEUROTRANSMITTER release is mediated by Ca2+ dependent exocytosis of synaptic vesicles', Neither the amount of transmitter released from individual synaptic vesicles nor the kinetics of this process have yet been directly determined, Using carbon fibres as electrochemical detectors(2,3), we have measured release of the neurotransmitter serotonin from cultured neurons of the leech(4). This technique allowed us to monitor transmitter discharge from single synaptic vesicles as spike-like oxidation currents at high time resolution, providing new insight into the mechanism of neuronal exocytosis, Two types of signals were characterized, corresponding to exocytosis of small clear and large dense core vesicles present in these cells, A small vesicle discharges about 4,700 transmitter molecules with a time constant in the region of 260 mu s, whereas large vesicles release their content of approximately 80,000 molecules with a time constant of about 1.3 ms, Release from both vesicle types is initiated rapidly, with a rise time of less than 60 mu s, suggesting an abrupt opening of a preassembled fusion pore.