Ultrafast Action Potentials Mediate Kilohertz Signaling at a Central Synapse
Ultrafast Action Potentials Mediate Kilohertz Signaling at a Central Synapse
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DOI：
10.1016/j.neuron.2014.08.036
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发表时间：
2014-10-01
期刊：
影响因子：
16.2
通讯作者：
Hallermann, Stefan
中科院分区：
文献类型：
--
作者：
Ritzau-Jost, Andreas;Delvendahl, Igor;Hallermann, Stefan
快速突触传递对于快速信息处理是重要的。为了探索神经元信号传导的最大速率并分析突触前机制，我们专注于小脑皮质的输入层，其中异常高的动作电位（AP）频率已被报道在体内。与成对的记录突触前小脑苔藓纤维结和突触后颗粒细胞，我们证明了可靠的神经传递高达类似1 kHz。突触前AP是超快的，具有类似于100 μ s的半持续时间。K-v1和K-v3钾通道介导快速复极化，快速失活钠通道确保代谢效率，在高达1.5 kHz的爆发期间几乎没有AP增宽。突触前Ca（v）2.1（P/Q型）钙通道在超快AP期间有效开放。此外，突触囊泡的子集紧密耦合到Ca 2+通道，囊泡被迅速招募到释放位点。这些数据揭示了突触前AP的产生和神经元kHz信号的基础递质释放的机制。
Fast synaptic transmission is important for rapid information processing. To explore the maximal rate of neuronal signaling and to analyze the presynaptic mechanisms, we focused on the input layer of the cerebellar cortex, where exceptionally high action potential (AP) frequencies have been reported in vivo. With paired recordings between presynaptic cerebellar mossy fiber boutons and postsynaptic granule cells, we demonstrate reliable neurotransmission up to similar to 1 kHz. Presynaptic APs are ultrafast, with similar to 100 mu s half-duration. Both K-v1 and K-v3 potassium channels mediate the fast repolarization, rapidly inactivating sodium channels ensure metabolic efficiency, and little AP broadening occurs during bursts of up to 1.5 kHz. Presynaptic Ca(v)2.1 (P/Q-type) calcium channels open efficiently during ultrafast APs. Furthermore, a subset of synaptic vesicles is tightly coupled to Ca2+ channels, and vesicles are rapidly recruited to the release site. These data reveal mechanisms of presynaptic AP generation and transmitter release underlying neuronal kHz signaling.