The influence of multivesicular release and postsynaptic receptor saturation on transmission at granule cell to Purkinje cell synapses
The influence of multivesicular release and postsynaptic receptor saturation on transmission at granule cell to Purkinje cell synapses
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DOI：
10.1523/jneurosci.4029-05.2005
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发表时间：
2005-12-14
影响因子：
5.3
通讯作者：
Regehr, WG
中科院分区：
文献类型：
--
作者：
Foster, KA;Crowley, JJ;Regehr, WG
突触的特性关键取决于动作电位是否可以在单个释放位点触发多个囊泡的释放[多囊泡释放（MVR）]以及单个囊泡的融合是否导致受体饱和。MVR和受体饱和都发生在一些高p突触，但不知道它们是否也发生在低p突触。在这里，我们研究这个问题在低p突触之间的平行纤维和浦肯野细胞使用低亲和力拮抗剂DGG（γ-D-谷氨酰甘氨酸），以减轻AMPA受体饱和。我们发现，存在的MVR和受体饱和在这个突触改变了突触传递的钙依赖性，并降低了促进的程度。这些研究结果表明，MVR和突触后受体饱和度可以影响传输，即使在突触与低初始释放概率，并表明这些属性可能是常见的在哺乳动物大脑中的突触。
The properties of a synapse are crucially dependent on whether an action potential can trigger the release of multiple vesicles at an individual release site [multivesicular release (MVR)] and whether fusion of a single vesicle leads to receptor saturation. MVR and receptor saturation both occur at some high p synapses, but it is not known whether they also occur at low p synapses. Here we examine this issue at the low p synapse between parallel fibers and Purkinje cells using the low-affinity antagonist DGG (gamma-D-glutamylglycine) to relieve AMPA receptor saturation. We find that the presence of MVR and receptor saturation at this synapse alters the calcium dependence of synaptic transmission and reduces the extent of facilitation. These findings establish that MVR and postsynaptic receptor saturation can influence transmission even at synapses with a low initial probability of release and suggest that these properties may be common at synapses in the mammalian brain.