Differential Equations Seminar

Title: Dimension reduction in a stochastic fire-diffuse-fire model reveals parameter regions for initiating calcium spiral wave

Abstract: Intra-cellular calcium dynamics in a cardiac cell can be described by a 3D stochastic fire-diffuse-fire model. To ease the computational complexity that comes with the exploration of sensitive model parameters in long time simulations, we consider one-dimensional model reductions; these reductions lead to the discovery of a parameter region that supports biophysical calcium waves in the 3D model. A further exploration of the biophysical boundary in the parameter space reveals a range of parameter values that have a high probability of initiating spiral patterns.  There is experimental evidence for spontaneous initiation of spiral waves. The intrinsic appearance of such patterns in our model is the result of an interplay between the

spatial regularity of release sites and the amplitude of calcium release.  No forced temporal heterogeneity nor spatial irregularity is required.