微秒脉冲电刺激对神经元动作电位发放影响的仿真研究

Simulation Study on the Effect of Microsecond Pulse Electrical Stimulation on the Release of the Neuronal Action Potential

为研究微秒脉冲电刺激对神经元动作电位发放特性的影响,结合笛卡尔传输网格和HH神经元等效电路模型建立3维神经元传输网格系统模型。在此基础上,仿真研究了刺激强度I改变而刺激脉宽τ不变、刺激τ改变而I不变、以及刺激剂量(I^2_τ)不变而强度I与脉宽τ均改变3种刺激方案下各参数分别对神经元动作电位发放特性的影响。研究结果表明:3种方案均存在刺激阈值,分别为25 n A、90.79μs;5.968 29 n A、400μs;112.52 n A、19.746μs。刺激参数大于阈值,神经元产生兴奋且可有效传递。沿轴突z方向(除刺激点)各处动作电位峰值随刺激参数增大基本不变,仅时延变长。刺激点处动作电位峰值与刺激参数大小正相关,但脉宽增大时其存在最大峰值。刺激参数小于阈值,神经元无法产生兴奋,沿轴突z方向各处动作电位峰值与刺激参数大小正相关。考虑作用效益和技术发展现状,可综合选取出最优参数。研究结果可为后续实验甚或临床研究提供刺激参数选取的理论依据,对进一步的机理研究具有一定的参考价值。

In order to study the effects of microsecond pulse electrical stimulation on the release characteristics of the neuronal action potential, we established a 3D neuronal transmission grid system model by combining the Cartesian transport lattice and the HH neuron equivalent circuit model. On this basis, the effects of the parameters of the three stimulus schemes on the release characteristics of neuronal action potential were simulated,and the schemes were as follows： different stimulus intensity I （I changed, τ unchanged）, different stimulus pulse duration τ（τ changed, I unchanged）, and stimulus dose （I^2r） unchanged but I and τ were changed. The research results show that all of the three schemes have thresholds, they are 25 hA, 90.79 gs; 400 kts, 5.968 29 nA; and 112.52 nA, 19.746 μs, respectively. When the stimulus parameters are greater than the threshold, the neuron is excited and can be transmitted effectively. The peak value of action potential along the z direction of the axon （except the stimulus point） is almost unchanged with the increase of the stimu- lation parameter, and the delay only becomes longer. The peak value of the action potential at the stimulus point is positively correlated with the size of the stimulus parameters. However, when the pulse width increases, there is a maxi- mum peak. When the stimulus parameter is less than the threshold, the neuron can not generate excitement. The peak value of the action potential along the z direction of the axon is positively correlated with the size of the stimulus parame- ter. Considering the effectiveness of the benefits and the current situation of the technological development, we can choose the optimal parameters synthetically. The results can provide a theoretical basis for the selection of stimulus parameters in the subsequent experimental research or even clinical studies, and it has a certain reference value for the further study of the mechanism.