Combined Mechanical Surface Wave and Ion Channel Activation Theories to Nerve Action Potential Propagation

Abstract

SUMMARY Several physics phenomena such as membrane potential mechanical deformation thermodynamic changes occur during the propagation of action potential on the axons of peripheral nerve The myelin affects the propagation speed of action potential In recent years new models such as Hodgkin-Huxley model and soliton model for the action potential have been proposed Although these models can describe the action potential and the mechanical changes the saltatory conduction still can not be explained by these model In this thesis the propagation of action potential is modeled as mechanical action wave propagated on the axon of nerve A mechanical model of ion channels and transduction mechanism of mechanical wave to action potential were proposed Finite element models of unmyelinated and myelinated axons were built and propagation of the action were simulated The results show that when stiffness of cytoplasm is smaller than cortex the propagation speed are in agreement with experimental results The viscosities of membrane and cytoplasm have no effect on radial but axial mechanical wave When the interaction between myelin and axon is contact the displacement stress and conduction speed are increased compared to unmyelinated axon The over-damped 2nd order mechanical model of ion channels could describe the transduction of stress wave to action potential at the distal end of the electro-mechanical model of axon The model developed in this thesis can simulate not only the propagation and generation of action potential but also the saltatory conduction

Date of Award	2020
Original language	English
Supervisor	Ming-Shaung Ju (Supervisor)