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脉冲磁场对神经元动作电位发放的影响

郑羽, 蔡迪, 王金海, 李刚, 林凌

天津工业大学电子与信息工程学院，天津 300387；天津大学精密测试技术及仪器国家重点实验室，天津 300072

摘要

磁场作用于生物体产生的生物效应被广泛研究。本文将脉冲磁场作用于神经元细胞，试图观察Na+通道的变化及其引起的动作电位的变化。选择频率15 Hz、强度1 mT的脉冲磁场刺激昆明小鼠大脑皮质神经元，随后进行全细胞膜片钳实验。结果显示，脉冲磁场延缓了Na+通道电流的激活，促进Na+通道电流的失活。基于经典的细胞三层介电模型，模拟了在脉冲磁场下细胞膜电位分布的极化图，结果显示诱发的膜电位大小与脉冲磁场的频率和强度有关。基于Hodgkin-Huxley (H-H)模型，仿真了脉冲磁场感应的电流作用于离子通道所产生的动作电位曲线，与不加刺激时候的曲线相比较，当外加电流在−1.32~0 μA时，动作电位的产生频率减小，幅值降低；当外加电流大于0 μA时，动作电位的产生频率增大，幅值变化不明显；当外加电流小于−1.32 μA时，动作电位的上升时间快速变短，峰值剧烈降低，无法形成完整的动作电位，即无动作电位。以上结果提示，磁场刺激可通过调节Na+通道影响神经元动作电位的发放频率和幅值。

关键词： 跨膜电位; 动作电位; Na+通道; 发放特性

分类号：Q689

[Effect of pulse magnetic field on distribution of neuronal action potential.] [Article in Chinese]

ZHENG Yu, CAI Di, WANG Jin-Hai, LI Gang, LIN Ling

School of Electronics and Information Engineering, Tianjin Polytechnic University, Tianjin 300387, China； State Key Laboratory of Precision Measurement Technology and Instruments, Tianjin University, Tianjin 300072, China

Abstract

The biological effect on the organism generated by magnetic field is widely studied. The present study was aimed to observe the change of sodium channel under magnetic field in neurons. Cortical neurons of Kunming mice were isolated, subjected to 15 Hz, 1 mT pulse magnetic stimulation, and then the currents of neurons were recorded by whole-cell patch clamp. The results showed that, under magnetic stimulation, the activation process of Na⁺ channel was delayed, and the inactivation process was accelerated. Given the classic three-layer model, the polarization diagram of cell membrane potential distribution under pulse magnetic field was simulated, and it was found that the membrane potential induced was associated with the frequency and intensity of magnetic field. Also the effect of magnetic field-induced current on action potential was simulated by Hodgkin-Huxley (H-H) model. The result showed that the generation of action potential was delayed, and frequency and the amplitudes were decreased when working current was between -1.32 μA and 0 μA. When the working current was higher than 0 μA, the generation frequency of action potential was increased, and the change of amplitudes was not obvious, and when the working current was lower than -1.32 μA, the time of rising edge and amplitudes of action potential were decreased drastically, and the action potential was unable to generate. These results suggest that the magnetic field simulation can affect the distribution frequency and amplitude of action potential of neuron via sodium channel mediation.

Key words: Transmembrane potential; action potential; sodium ion channel; distribution characteristics

收稿日期：2013-12-02　　录用日期：2014-02-13

通讯作者：王金海　　E-mail: wangjinhai@tjpu.edu.cn

引用本文：

郑羽, 蔡迪, 王金海, 李刚, 林凌. 脉冲磁场对神经元动作电位发放的影响[J]. 生理学报 2014; 66 (4): 438-448.

ZHENG Yu, CAI Di, WANG Jin-Hai, LI Gang, LIN Ling. [Effect of pulse magnetic field on distribution of neuronal action potential.] [Article in Chinese]. Acta Physiol Sin 2014; 66 (4): 438-448 (in Chinese with English abstract).