Local Postsynaptic Voltage-Gated Sodium Channel Activation in Dendritic Spines of Olfactory Bulb Granule Cells
Local Postsynaptic Voltage-Gated Sodium Channel Activation in Dendritic Spines of Olfactory Bulb Granule Cells
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DOI：
10.1016/j.neuron.2014.12.051
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发表时间：
2015-02-04
期刊：
影响因子：
16.2
通讯作者：
Egger, Veronica
中科院分区：
文献类型：
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作者：
Bywalez, Wolfgang G.;Patirniche, Dinu;Egger, Veronica
神经元树突棘被推测为独立的计算单元，但在棘中进行主动电计算的证据很少。在这里，我们表明，严格的本地电压门控钠通道（Na-V）激活过程中可以发生在兴奋性突触后电位的嗅球颗粒细胞，我们模仿和检测通过结合双光子uncaging谷氨酸和钙成像与全细胞记录。我们发现，局部Na-V激活促进钙进入脊髓通过高电压激活的钙通道，并加速突触后体细胞去极化，而不影响NMDA受体介导的信号。因此，Na-v介导的加强促进从倒向颗粒细胞棘到侧二尖瓣细胞树突的快速输出，从而可以加速复发性抑制。这个引人注目的电区室化的例子既增加了对嗅觉网络处理的理解，也拓宽了对脊柱功能的一般看法。
Neuronal dendritic spines have been speculated to function as independent computational units, yet evidence for active electrical computation in spines is scarce. Here we show that strictly local voltage-gated sodium channel (Na-v) activation can occur during excitatory postsynaptic potentials in the spines of olfactory bulb granule cells, which we mimic and detect via combined two-photon uncaging of glutamate and calcium imaging in conjunction with whole-cell recordings. We find that local Na-v activation boosts calcium entry into spines through high-voltage-activated calcium channels and accelerates postsynaptic somatic depolarization, without affecting NMDA receptor-mediated signaling. Hence, Na-v-mediated boosting promotes rapid output from the reciprocal granule cell spine onto the lateral mitral cell dendrite and thus can speed up recurrent inhibition. This striking example of electrical compartmentalization both adds to the understanding of olfactory network processing and broadens the general view of spine function.