Zhao Shouguo, Yang Guangning, Wang Jicheng, Roppolo James R, de Groat William C, Tai Changfeng
Department of Urology, University of Pittsburgh Pittsburgh, PA, USA ; Department of Biomedical Engineering, Beijing Jiaotong University Beijing, China.
Department of Urology, University of Pittsburgh Pittsburgh, PA, USA.
Front Comput Neurosci. 2015 Jul 6;9:86. doi: 10.3389/fncom.2015.00086. eCollection 2015.
This study used the Frankenhaeuser-Huxley axonal model to analyze the effects of non-symmetric waveforms on conduction block of myelinated axons induced by high-frequency (10-300 kHz) biphasic electrical stimulation. The results predict a monotonic relationship between block threshold and stimulation frequency for symmetric waveform and a non-monotonic relationship for non-symmetric waveforms. The symmetric waveform causes conduction block by constantly activating both sodium and potassium channels at frequencies of 20-300 kHz, while the non-symmetric waveforms share the same blocking mechanism from 20 kHz up to the peak threshold frequency. At the frequencies above the peak threshold frequency the non-symmetric waveforms block axonal conduction by either hyperpolarizing the membrane (if the positive pulse is longer) or depolarizing the membrane (if the negative pulse is longer). This simulation study further increases our understanding of conduction block in myelinated axons induced by high-frequency biphasic electrical stimulation, and can guide future animal experiments as well as optimize stimulation parameters that might be used for electrically induced nerve block in clinical applications.
本研究使用Frankenhaeuser-Huxley轴突模型，分析非对称波形对高频（10 - 300 kHz）双相电刺激诱导的有髓轴突传导阻滞的影响。结果预测，对称波形的阻滞阈值与刺激频率之间呈单调关系，而非对称波形则呈非单调关系。对称波形通过在20 - 300 kHz频率下持续激活钠通道和钾通道来导致传导阻滞，而非对称波形在20 kHz直至峰值阈值频率范围内具有相同的阻滞机制。在高于峰值阈值频率时，非对称波形通过使膜超极化（如果正脉冲更长）或使膜去极化（如果负脉冲更长）来阻断轴突传导。这项模拟研究进一步加深了我们对高频双相电刺激诱导的有髓轴突传导阻滞的理解，并可指导未来的动物实验以及优化可能用于临床应用中电诱导神经阻滞的刺激参数。
