Facilitation at single synapses probed with optical quantal analysis
Facilitation at single synapses probed with optical quantal analysis
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DOI：
10.1038/nn867
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发表时间：
2002-07-01
影响因子：
25
通讯作者：
Svoboda, K
中科院分区：
文献类型：
--
作者：
Oertner, TG;Sabatini, BL;Svoboda, K
许多突触可以以使用依赖的方式迅速改变它们的强度，但这种短期可塑性的机制仍然未知。为了理解这些机制，需要测量单个突触的神经递质释放。我们通过成像大鼠脑切片中CA 1锥体神经元的单个树突棘中突触N-甲基-D-天冬氨酸受体（NMDAR）介导的[Ca 2 +]短暂增加来探测递质释放，从而实现单个突触的量子分析。我们发现，释放概率的变化，产生成对脉冲易化（PPF）或操纵突触前腺苷受体，与突触间隙中谷氨酸浓度的变化，表明单个突触可以释放一个变量的谷氨酸每个动作电位。释放概率和响应大小之间的关系与囊泡释放的二项式模型一致，每个活性区有几个（> 5个）独立的释放位点，表明多囊泡释放有助于这些突触的易化。
Many synapses can change their strength rapidly in a use-dependent manner, but the mechanisms of such short-term plasticity remain unknown. To understand these mechanisms, measurements of neurotransmitter release at single synapses are required. We probed transmitter release by imaging transient increases in [Ca2+] mediated by synaptic N-methyl-D-aspartate receptors (NMDARs) in individual dendritic spines of CA1 pyramidal neurons in rat brain slices, enabling quantal analysis at single synapses. We found that changes in release probability, produced by paired-pulse facilitation (PPF) or by manipulation of presynaptic adenosine receptors, were associated with changes in glutamate concentration in the synaptic cleft, indicating that single synapses can release a variable amount of glutamate per action potential. The relationship between release probability and response size is consistent with a binomial model of vesicle release with several (> 5) independent release sites per active zone, suggesting that multivesicular release contributes to facilitation at these synapses.