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arXiv 1711.03383q-bio.NC
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神经元群体动作电位编码的时间精确性需要轴突起始段

An axon initial segment is required for temporal precision in action potential encoding by neuronal populations

Elinor Lazarov, Melanie Dannemeyer, Barbara Feulner, Jörg Enderlein, Michael J. Gutnick, Fred Wolf, Andreas Neef

摘要:

中枢神经元在轴突起始段(AIS)中启动动作电位(AP),轴突起始段是一个以高浓度的电压依赖性离子通道和以规则的纳米级模式排列的专门的细胞骨架锚定蛋白为特征的隔室。虽然AIS是神经元的一项关键进化创新,但它带来的功能益处尚不清楚。使用AIS细胞骨架蛋白β IV-血影蛋白的突变,我们在这里建立了一个具有扰动AIS结构的神经元的体外模型,该结构保留了纳米级顺序,但失去了维持高NaV密度的能力。结合实验和模拟,我们表明,在AIS中的高NaV密度是不需要轴突AP启动,但它是至关重要的高带宽的信息编码和AP定时精度。我们的研究结果提供了第一个实验证明轴突AP启动没有高轴突通道密度,并建议增加带宽的神经元代码,因此网络功能的计算效率是一个主要的好处的AIS的演变。

英文摘要:

Central neurons initiate action potentials (APs) in the axon initial segment (AIS), a compartment characterized by a high concentration of voltage-dependent ion channels and specialized cytoskeletal anchoring proteins arranged in a regular nanoscale pattern. Although the AIS was a key evolutionary innovation in neurons, the functional benefits it confers are not clear. Using a mutation of the AIS cytoskeletal protein βIV-spectrin, we here establish an in vitro model of neurons with a perturbed AIS architecture that retains nanoscale order but loses the ability to maintain a high NaV density. Combining experiments and simulations we show that a high NaV density in the AIS is not required for axonal AP initiation; it is however crucial for a high bandwidth of information encoding and AP timing precision. Our results provide the first experimental demonstration of axonal AP initiation without high axonal channel density and suggest that increasing the bandwidth of the neuronal code and hence the computational efficiency of network function was a major benefit of the evolution of the AIS.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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