横向电场作用下外周神经的兴奋模型  

Modeling for Activating Peripheral Nerves by Transverse Electric Field

作　　者：于辉[1] 王毅[1] 郑崇勋[1] 

机构地区：[1]西安交通大学生物医学工程研究所,西安710049

出　　处：《生物医学工程学杂志》2005年第5期865-869,共5页Journal of Biomedical Engineering

基　　金：国家自然科学基金资助项目(30170257)

摘　　要：外周神经的兴奋机理研究是以神经生理学的电缆方程为基础,方程中的激励因子只与外电场沿神经方向的纵向电场分量有关。但实验表明垂直于神经走向的横向电场也可以兴奋外周神经,因而传统电缆方程不能客观反映外周神经兴奋实际过程而需要改进。本文基于两阶段过程,建立了横向电场作用下外周神经的兴奋模型,表明了在横向电场作用下沿朗飞氏结径向的净内向电流导致了神经兴奋,从而阐述了外周神经在横向电场中的兴奋机理,改进了经典电缆方程。模型通过了离体实验验证。此改进的电缆方程可以描述任意电场激励下的外周神经兴奋。The classical cable function has been used to represent the response of peripheral nerves stimulated by external parallel electric field. It can not describe the excitation of peripheral nerves stimulated by perpendicular electric field. In this paper, responses of the nodes of Ranvier to transverse-field are deeply investigated by mathematic simulation and in-vitro experiments. The paper demonstrates that, under perpendicular electric field stimulation, the responses evoke a two-stage process including an initial polarization and the actual change of the transmembrane potential. It is the net inward current along a radial direction of the node of Ranvier that causes the peripheral nerve excitation. Based on the two-stage process, a novel model is introduced to describe peripheral nerves stimulated by transverse-field, and the classical cable function is modified. The new model and the improved cable function are verified by several in-vitro experiments. They can be used to represent peripheral nerves responses by arbitrary electric field stimulation.

关 键 词：横向电场 电缆方程 神经兴奋 外周神经 外周神经 横向电场 神经兴奋 模型 电缆方程 机理研究 离体实验 神经生理学 

分 类 号：R318.04[医药卫生—生物医学工程]