Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
BP: Fachverband Biologische Physik
BP 15: Physics of Cells II
BP 15.2: Vortrag
Dienstag, 23. März 2010, 14:45–15:00, H43
Sensitisation waves in a bidomain fire-diffuse-fire model of intracellular Ca2+ dynamics — •Rüdiger Thul1, Steven Coombes1, and Greg D Smith2 — 1School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD, UK — 2Department of Applied Mathematics, The College of William and Mary, Williamsburg, VA 23187, USA
We present a bidomain threshold model of intracellular calcium (Ca2+ ) dynamics in which, as suggested by recent experiments, the cytosolic threshold for Ca2+ liberation is modulated by the Ca2+ concentration in the releasing compartment. We explicitly construct stationary fronts and determine their stability using an Evans function approach. Our results show that a biologically motivated choice of a dynamic threshold, as opposed to a constant threshold, can pin stationary fronts that would otherwise be unstable. This illustrates a novel mechanism to stabilise pinned interfaces in continuous excitable systems. Our framework also allows us to compute travelling pulse solutions in closed form and systematically probe the wave speed as a function of physiologically important parameters. We find that the existence of travelling wave solutions depends on the time scale of the threshold dynamics, and that facilitating release by lowering the cytosolic threshold increases the wave speed.