title: Ephaptic conduction in a cardiac strand model with 3D electrodiffusion.
abstract: We study cardiac action potential propagation under severe reduction in gap junction conductance. We use a mathematical model of cellular electrical activity that takes into account both three-dimensional geometry and ionic concentration effects. Certain anatomical and biophysical parameters are varied to see their impact on cardiac action potential conduction velocity. This study uncovers quantitative features of ephaptic propagation that differ from previous studies based on one-dimensional models. We also identify a mode of cardiac action potential propagation in which the ephaptic and gap-junction-mediated mechanisms alternate. Our study demonstrates the usefulness of this modeling approach for electrophysiological systems especially when detailed membrane geometry plays an important role.
authors.affiliation: Department of Mathematics, University of British Columbia, Vancouver, BC, Canada. mori@math.ubc.ca
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Mori
authors.forename: Glenn I
authors.initials: GI
authors.lastname: Fishman
authors.forename: Charles S
authors.initials: CS
authors.lastname: Peskin
mesh_terms: D000200:Action Potentials; D000818:Animals; D004058:Diffusion; D004553:Electric Conductivity; D017629:Gap Junctions; D006321:Heart / Q000502:physiology*; D006329:Heart Conduction System / Q000502:physiology*; D051379:Mice; D008955:Models, Cardiovascular; D055672:Static Electricity