Pacific Institute for the Mathematical Sciences - PIMS

Mathematical models of calcium regulation in cardiac cells

Calcium is a ubiquitous signaling molecule involved in the regulation
of a wide range of processes. In cardiac cells, calcium plays a key
role in mediating the electrical-excitation and contraction processes.
Three mathematical models of calcium regulation are derived and
analyzed. Using a simplified model, we first show that release
localization, diffusion, and single-channel activity modulate the onset
of calcium oscillations. These factors are of particular importance in
cardiac cells where calcium release is spatially inhomogeneous and
inherently stochastic. However, models that take these effects into
account are computationally expensive to simulate. Using a variety of
asymptotic approximations, we derive a simplified yet reliable model of
stochastic calcium flux through a release unit. Finally, we use a
whole-cell model to explore the role of calcium oscillations in the
generation of periodic action potentials based on recent experimental
studies on the sinoatrial node and embryonic cardiac cells.

2:00pm, WMAX 216