Presynaptic NMDARs in the Hippocampus Facilitate Transmitter Release at Theta Frequency
Presynaptic NMDARs in the Hippocampus Facilitate Transmitter Release at Theta Frequency
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DOI：
10.1016/j.neuron.2010.11.023
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发表时间：
2010-12-22
期刊：
影响因子：
16.2
通讯作者：
Emptage, Nigel J.
中科院分区：
文献类型：
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作者：
McGuinness, Lindsay;Taylor, Chanel;Emptage, Nigel J.
[Ca2+](i)的升高为神经元钮扣释放神经递质提供了触发器。我们已经使用共聚焦显微镜和Ca2+敏感染料直接测量动作电位诱发[Ca2+](i)在谢弗侧枝的钮扣。这表明，诱发Ca2+瞬态的每次试验振幅是双峰分布的。我们证明，当突触前NMDA受体在释放递质后被激活时，会发生“大”Ca2+瞬态。突触前NMDA受体的激活被证明是促进θ频率传输的关键。因为大的Ca2+瞬态“报告”发射机释放，它们的频率在逐个试验的基础上可以用来估计释放的概率，p(r)。我们用这个新的估计表明p(r)随着长时程增强的诱导而增加。
A rise in [Ca2+](i) provides the trigger for neurotransmitter release at neuronal boutons. We have used confocal microscopy and Ca2+ sensitive dyes to directly measure the action potential-evoked [Ca2+](i) in the boutons of Schaffer collaterals. This reveals that the trial-by-trial amplitude of the evoked Ca2+ transient is bimodally distributed. We demonstrate that "large" Ca2+ transients occur when presynaptic NMDA receptors are activated following transmitter release. Presynaptic NMDA receptor activation proves critical in producing facilitation of transmission at theta frequencies. Because large Ca2+ transients "report" transmitter release, their frequency on a trial-by-trial basis can be used to estimate the probability of release, p(r). We use this novel estimator to show that p(r) increases following the induction of long-term potentiation.