不同频率磁刺激对离体脑片神经元兴奋性及电压门控型钾通道影响的研究  

Effects of magnetic stimulation at different frequencies on neuronal excitability and voltage-gated potassium channels in vitro brain slices

作　　者：尹晓楠 徐桂芝[1,2] 朱海军 付蕊 李洋 丁冲 YIN Xiaonan;XU Guizhi;ZHU Haijun;FU Rui;LI Yang;DING Chong(State Key Laboratory of Reliability and Intelligence of Electrical Equipment,School of Electrical Engineering,Hebei University of Technology,Tianjin 300130,P.R.China;Tianjin Key Laboratory of Bioelectromagnetic Technology and Intelligent Health,Hebei University of Technology,Tianjin 300130,P.R.China;School of Pharmacy,North China University of Science and Technology,Tangshan,Hebei 063210,P.R.China)

机构地区：[1]河北工业大学电气工程学院省部共建电工装备可靠性与智能化国家重点实验室,天津300130 [2]河北工业大学电气工程学院天津市生物电工与智能健康重点实验室,天津300130 [3]华北理工大学药学院,河北唐山063210

出　　处：《生物医学工程学杂志》2021年第2期224-231,共8页Journal of Biomedical Engineering

基　　金：国家自然科学基金重点项目(51737003);国家自然科学基金面上项目(51677053,52077057);国家自然科学基金青年基金(51507046)。

摘　　要：经颅磁刺激作为一种无创的神经调控技术,广泛地应用于神经和精神类疾病的临床治疗,但其神经调控的作用机制尚不清楚。本文旨在从神经元电生理角度研究不同频率的磁刺激对离体脑片神经元兴奋性和电压门控型钾通道的影响。实验分为刺激组和对照组,刺激组对急性分离的小鼠脑片分别施加同一强度(0.3 T)下不同频率(20 Hz和0.5 Hz)的磁刺激(500个脉冲)。利用全细胞膜片钳技术记录海马齿状回颗粒神经元的静息膜电位、动作电位和电压门控型钾通道电流。结果显示,20 Hz磁刺激显著增加了动作电位的发放个数以及单个动作电位的最大斜率,降低了动作电位的阈值、半波宽和达峰时间,提高了海马神经元的兴奋性;降低了钾通道的电流峰值,瞬时外向钾通道的失活曲线明显左移,失活后复活的时间常数明显增大。0.5 Hz磁刺激则显著抑制了神经元兴奋性,提高了钾通道的电流峰值,但通道的动力学特征没有明显变化。结果提示,海马齿状回颗粒细胞电压门控钾通道的动力学特征和神经元的兴奋性,可能是磁刺激进行神经调控的潜在机制之一。As a noninvasive neuromodulation technique,transcranial magnetic stimulation(TMS)is widely used in the clinical treatment of neurological and psychiatric diseases,but the mechanism of its action is still unclear.The purpose of this paper is to investigate the effects of different frequencies of magnetic stimulation(MS)on neuronal excitability and voltage-gated potassium channels in the in vitro brain slices from the electrophysiological perspective of neurons.The experiment was divided into stimulus groups and control group,and acute isolated mice brain slices were applied to MS with the same intensity(0.3 T)at different frequencies(20 Hz and 0.5 Hz,500 pulses)respectively in the stimulus groups.The whole-cell patch clamp technique was used to record the resting membrane potential(RMP),action potential(AP),voltage-gated potassium channels current of hippocampal dentate gyrus(DG)granule cells.The results showed that 20 Hz MS significantly increased the number of APs released and the maximum slope of a single AP,reduced the threshold of AP,half width and time to AP peak amplitude,and improved the excitability of hippocampal neurons.The peak currents of potassium channels were decreased,the inactivation curve of transient outward potassium channels shifted to the left significantly,and the time constant of recovery after inactivation increased significantly.0.5 Hz MS significantly inhibited neuronal excitability and increased the peak currents of potassium channels,but the dynamic characteristics of potassium channels had little change.The results suggest that the dynamic characteristics of voltagegated potassium channels and the excitability of hippocampal DG granule neurons may be one of the potential mechanisms of neuromodulation by MS.

关 键 词：磁刺激 动作电位 瞬时外向钾通道 延迟整流钾通道 

分 类 号：R338[医药卫生—人体生理学]