We review the experimental and computational data about the propagation of neural signals in myelinated axons in mice, cats, rabbits, and frogs published in the past five decades. In contrast to the natural assumption that neural signals occur one by one in time and in space, we figure out that neural signals are highly overlapped in time between neighboring nodes. This phenomenon was occasionally illustrated in some early reports, but seemed to have been overlooked for some time. The shift in time between two successive neural signals from neighboring nodes, defined as relay time τ, was calculated to be only 16.3 μs–87.0 μs, i.e., 0.8 %–4.4 % of the average duration of an action potential peak (roughly 2 ms). We present a clearer picture of the exact physical process about how the information transmits along a myelinated axon, rather than a whole action potential peak, what is transmitted is only a rising electric field caused by transmembrane ion flows. Here in the paper, τ represents the waiting time until the neighboring node senses an attenuated electric field reaching the threshold to trigger the open state. The mechanisms addressed in this work have the potential to be universal, and may hold clues to revealing the exact triggering processes of voltage-gated ion channels and various brain functions.

我们回顾了过去五年发表的关于小鼠、猫、兔子和青蛙有髓轴突中神经信号传播的实验和计算数据。与神经信号在时间和空间中一一发生的自然假设相反，我们发现神经信号在相邻节点之间的时间上高度重叠。这种现象偶尔会在一些早期的报道中有所说明，但似乎被忽视了一段时间。来自相邻节点的两个连续神经信号之间的时间偏移，定义为中继时间τ，计算结果仅为 16.3 μs–87.0 μs，即, 动作电位峰值平均持续时间的 0.8 %–4.4 %（大约 2 毫秒）。我们更清晰地展示了信息如何沿着有髓轴突传输的确切物理过程，而不是整个动作电位峰值，传输的只是由跨膜离子流引起的上升电场。在本文中，τ表示等待时间，直到相邻节点感应到衰减电场达到阈值以触发打开状态。这项工作中涉及的机制具有普遍适用的潜力，并且可能为揭示电压门控离子通道和各种大脑功能的确切触发过程提供线索。