Calcium dynamics on a stochastic reaction-diffusion lattice model

NARA GUISONI; MÁRIO JOSÉ DE OLIVEIRA

PHYSICAL REVIEW E - STATISTICAL PHYSICS, PLASMAS, FLUIDS AND RELATED INTERDISCIPLINARY TOPICS

American Physical Society

Año: 2006 vol. 74 p. 619051 - 619056

1063-651X

We study a stochastic reaction-diffusion lattice model for describing the calcium dynamics in the endoplasmic reticulum (ER) membrane. Calcium channels and calcium ions are placed in two interpenetrating square lattices which are connected by calcium release and diffusion. Calcium ions are released from the ER through the channels and they can both remain in the membrane or spontaneously leave the membrane into the cytosol. The state of the channel is modulated by calcium ions: a channel can be open, closed, or inactive. The model is studied by numerical simulations and mean field theory and exhibits a phase transition from an active state to an absorbing state which is the result of the catalytic calcium release. The critical behavior of the model is in the directed percolation universality class.