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DY: Dynamik und Statistische Physik
DY 46: Poster
DY 46.44: Poster
Donnerstag, 30. März 2006, 16:00–18:00, P1
Hybrid model for investigating the role of Ca2+ buffers in intracellular Ca2+ dynamics — •Stefan Zeller1, Martin Falcke2, Sten Rüdiger2, and Harald Engel1 — 1Institut für Theoretische Physik, TU-Berlin, Hardenbergstr. 36, 10623 Berlin, Germany — 2Abteilung Theorie SF5, Hahn-Meitner-Institut, Glienicker Str. 100, 14109 Berlin, Germany
We have modelled a four-component reaction-diffusion system with excitable elements, which are distributed inhomogeneously in a two-dimensional spatial domain. The source terms of the activator are spatially discrete and behave stochastically. With this model we investigate Ca2+ liberation through inositol 1,4,5-trisphosphate receptors which plays an universal role in cell regulation. Moreover, the specificity of cell signalling is achieved through the spatiotemporal patterning of Ca2+ signals.
Our interest is directed towards experiments [1] which have shown that mobile cytosolic Ca2+ buffers are modulating the coupling between the excitable elements. Surprisingly, a buffer with fast ’on-rates’ should weaken the coupling but leads to more activation and a globalization of spatially uniform Ca2+ signals. To understand the role of the Ca2+ buffers for the Ca2+ dynamics in the cytosol, we perform adaptive numerical simulations of a hybrid stochastic and deterministic model.
[1] Sheila L. Dargan and Ian Parker, Buffer kinetics shape the spatiotemporal patterns of IP3-evoked Ca2+ signals, J. Physiol (2003), 533.3, pp.775-788