Berlin 2012 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 18: Posters: Statistical Physics in Biological Systems

BP 18.21: Poster

Mittwoch, 28. März 2012, 17:30–19:30, Poster A

Effects of interactions between ion channels on neuronal dynamics — •Ekaterina Zhuchkova, Dmitry Zarubin, and Susanne Schreiber — Institute for Theoretical Biology, Humboldt-Universität zu Berlin and BCCN Berlin, Germany

Electrical signaling in our brain and heart relies on the opening or closing of individual stochastic units, so-called ion channels. Since Hodgkin and Huxley’s model of action potential (AP) initiation, the prevailing assumption is that ion channels act independently; they change their open probability in response to a common signal such as the membrane voltage, but do not directly influence each other. However, evidence for additional interactions between channels accumulates.

Consequences of such enhancing or hindering interactions between ion channels for neuronal spiking dynamics can be expected. Nevertheless, they have so far received relatively little attention in the analysis of excitable membranes. Here, we use bifurcation analysis and stochastic simulations of an extended Morris-Lecar model to understand how cooperative and anticooperative gating between ion channels changes basic sub- and suprathreshold voltage dynamics. The effects of channel interactions include the modification of the range of sustained firing and cell-intrinsic noise, the prolongation of AP duration, the occurrence of multistability and type-3-like firing. We hypothesize that channel interactions could be an efficient mechanism to regulate neuronal activity.

Acknowledgments.—Funded by BMBF (01GQ0901, 01GQ1001A, 01GQ0972).