Drift-Diffusion Simulations of Potassium Channels

Ionic channels play an important role in regulating the cell’s membrane potential and internal charge. This paper will focus on a continuum model of the KcsA potassium channel. We will derive the Poisson-Nernst-Planck (PNP) equations in general and then provide computational solutions for a 1D KcsA channel using experimentally determined parameters. The solution to the PNP equations consists of the time-dependent charge densities of each ion, coupled with the electric potential. The results will be used to solve for the time-dependent current in the channel in response to different time-dependent voltage signals, which can be compared with experimental data. 36 Copyright © SIAM Unauthorized reproduction of this article is prohibited