The assertion that large-diameter nerve fibers have low thresholds and small-diameter fibers have high thresholds in response to electrical stimulation has been held in a nearly axiomatic regard in the field of neuromodulation and neuroprosthetics. In contrast to the short pulses used to evoke action potentials, long-duration ionic direct current has been shown to block neural activity. We propose that the main determinant of the neural sensitivity to direct current block is not the size of the axon but the types of voltage-gated sodium channels prevalent in its neural membrane. On the basis of the variants of voltage-gated sodium channels expressed in different types of neurons in the peripheral nerves, we hypothesized that the small-diameter nociceptive fibers could be preferentially blocked. We show the results of a computational model and in vivo neurophysiology experiments that offer experimental validation of this novel phenomenon.

中文翻译：

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传入神经元中电压门控钠通道的差异表达通过离子直流电产生选择性神经阻滞。

大直径神经纤维具有低阈值而小直径纤维具有高阈值以响应电刺激的主张已在神经调节和神经修复领域中以近乎公理的方式提出。与用于唤起动作电位的短脉冲相反，长期的离子直流电已显示出阻断神经活动的作用。我们认为神经敏感性对直流阻滞的主要决定因素不是轴突的大小，而是其神经膜中普遍存在的电压门控钠通道的类型。基于在周围神经中不同类型的神经元中表达的电压门控钠通道的变异，我们假设小直径伤害感受纤维可以被优先阻断。