Modeling study of the effects of membrane surface charge on calcium microdomains and neurotransmitter release.

ABSTRACT: Synchronous neurotransmitter release is mediated by the opening of voltage-gated Ca(2+) channels and the build-up of submembrane Ca(2+) microdomains. Previous models of Ca(2+) microdomains have neglected possible electrostatic interactions between Ca(2+) ions and negative surface charges on the inner leaflet of the plasma membrane. To address the effects of these interactions, we built a computational model of ion electrodiffusion described by the Nernst-Planck and Poisson equations. We found that inclusion of a negative surface charge significantly alters the spatial characteristics of Ca(2+) microdomains. Specifically, close to the membrane, Ca(2+) ions accumulate, as expected from the strong electrostatic attraction exerted on positively charged Ca(2+) ions. Farther away from the membra

SUBMITTER: Catacuzzeno L 

PROVIDER: S-EPMC2517031 | biostudies-literature | 2008 Sep

REPOSITORIES: biostudies-literature