期刊
JOURNAL OF NEUROSCIENCE
卷 25, 期 26, 页码 6221-6234出版社
SOC NEUROSCIENCE
DOI: 10.1523/JNEUROSCI.3003-04.2005
关键词
VGLUT1; glutamate release; quantal size; homeostatic; excitatory; vesicular transporter
资金
- NCRR NIH HHS [1P29RR16816, P20 RR016816] Funding Source: Medline
- NIMH NIH HHS [MH58880, P50 MH058880] Funding Source: Medline
- NINDS NIH HHS [R01 NS036936, R01 NS037342, NS37342, NS36936] Funding Source: Medline
A fundamental question in synaptic physiology is whether the unitary strength of a synapse can be regulated by presynaptic characteristics and, if so, what those characteristics might be. Here, we characterize a newly proposed mechanism for altering the strength of glutamatergic synapses based on the recently identified vesicular glutamate transporter VGLUT1. Weprovide direct evidence that filling in isolated synaptic vesicles is subject to a dynamic equilibrium that is determined by both the concentration of available glutamate and the number of vesicular transporters participating in loading. We observe that changing the number of vesicular transporters expressed at hippocampal excitatory synapses results in enhanced evoked and miniature responses and verify biophysically that these changes correspond to an increase in the amount of glutamate released per vesicle into the synaptic cleft. In addition, we find that this modulation of synaptic strength by vesicular transporter expression is endogenously regulated, both across development to coincide with a maturational increase in vesicle cycling and quantal amplitude and by excitatory and inhibitory receptor activation in mature neurons to provide an activity-dependent scaling of quantal size via a presynaptic mechanism. Together, these findings underscore that vesicular transporter expression is used endogenously to directly regulate the extent of glutamate release, providing a concise presynaptic mechanism for controlling the quantal efficacy of excitatory transmission during synaptic refinement and plasticity.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据