Modeling and Simulation of Action Potential in Axoplasmic Fluid A Computational Study

Abstract

newlineAmongst all the cells of the body, neurons are considered to be the most remarkable by being able to propagate the signal at very high speed over a large distances. This is done with the help of generated action potential which travels down the axon to synaptic cleft to transfer the information from one neuron to the other neuron. Over the time, many approaches have been proposed for modeling action potential. In this work, axoplasmic composition of axon has been utilized to model the action potential phenomenon and the model has been named MAPAF: Model for Action Potential in Axoplasmic Fluidquot. Given the fact that 87 percent of axoplasm composition is water, action potential has been modeled using fluid dynamics approach along the axial direction of axoplasm. The model is governed by the generalized fluid equation coupled with conductance based Hodgkin-Huxley model (H-H model) to analyze the action potential phenomenon with respect to axoplasmic fluid properties. In our model, we have incorporated the parameters, membrane voltage, ionic conductances, gating parameters for ionic channels and temperature taken from H-H model. In addition to these, we have also defined and used the parameters representing density, pressure, mass fraction of ions, rate of addition of ions and temperature dependent ionic diffusivities both in axial and radial directions. The values obtained for action potential propagation velocity, axoplasmic fluid viscosity and temperature dependent longitudinal ionic diffusivities are well within the ranges given in the literature. This validates our approach for modeling action potential by considering the axoplasm as a fluid. Hence the proposed model, MAPAF has provided us with better understanding of the action potential. The model has also been analyzed for the parameters which will be affected by anesthesia and it gives a framework for analyzing the neuronal behavior in presence of anesthesia. This framework can be further utilized as an alternative to drug therapists for preparation of anesthetic drugs that can target the parameters affected by anesthesia