Wave failure at strong coupling in intracellular Ca2+ signaling system with clustered channels

As an important intracellular signal, Ca2+ ions control diverse cellular functions. In this paper, we discuss the Ca2+ signaling with a two-dimensional model in which the inositol 1,4,5-trisphosphate (IP3) receptor channels are distributed in clusters on the endoplasmic reticulum membrane. The wave failure at large Ca2+ diffusion coupling is discussed in detail in the model. We show that with varying model parameters the wave failure is a robust behavior with either deterministic or stochastic channel dynamics. We suggest that the wave failure should be a general behavior in inhomogeneous diffusing systems with clustered excitable regions and may occur in biological Ca2+ signaling systems.