A heterogeneous "resting" pool of synaptic vesicles that is dynamically interchanged across boutons in mammalian CNS synapses
A heterogeneous "resting" pool of synaptic vesicles that is dynamically interchanged across boutons in mammalian CNS synapses
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DOI：
10.1007/s11068-008-9030-y
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发表时间：
2008-08-01
期刊：
影响因子：
--
通讯作者：
Ryan, Timothy A.
中科院分区：
文献类型：
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作者：
Fernandez-Alfonso, Tomas;Ryan, Timothy A.
使用pHluorin标记的突触囊泡蛋白，我们已经研究了这些探针在海马神经末梢的细胞培养中的回收和nonrecycling池的分区。我们的研究表明，对于三种主要的突触囊泡成分，vGlut-1，VAMP-2和Synaptotagmin I，50-60%的标记蛋白质出现在循环池中，通过动员和与质膜融合，很容易对持续的动作电位刺激做出反应，而其余的则针对非循环，酸性隔室。回收和nonrecycling（或休息）池的分数变化显着的单个轴突内的终扣，从100%休息（沉默）到100%回收。单终扣漂白研究表明，回收和休息池是动态的和突触终扣之间的交换。这里概述的方法可以提取的定量参数应该有助于阐明静息囊泡池的潜在功能作用。
Using pHluorin-tagged synaptic vesicle proteins we have examined the partitioning of these probes into recycling and nonrecycling pools at hippocampal nerve terminals in cell culture. Our studies show that for three of the major synaptic vesicle components, vGlut-1, VAMP-2, and Synaptotagmin I, 50-60% of the tagged protein appears in a recycling pool that responds readily to sustained action potential stimulation by mobilizing and fusing with the plasma membrane, while the remainder is targeted to a nonrecycling, acidic compartment. The fraction of recycling and nonrecycling (or resting) pools varied significantly across boutons within an individual axon, from 100% resting (silent) to 100% recycling. Single-bouton bleaching studies show that recycling and resting pools are dynamic and exchange between synaptic boutons. The quantitative parameters that can be extracted with the approaches outlined here should help elucidate the potential functional role of the resting vesicle pool.