Dresden 2003 – wissenschaftliches Programm

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DY: Dynamik und Statistische Physik

DY 14: Statistical physics in biological systems I

DY 14.1: Hauptvortrag

Montag, 24. März 2003, 14:30–15:00, G\"OR/226

Stochastic Resonance in Ion Channels — •Igor Goychuk — Institut für Physik, Universität Augsburg, Augsburg, Germany; Bogolyubov Institute for Theoretical Physics, Kiev, Ukraine

To which minimal level of the biological organization can the stochastic resonance (SR) effects in biology be traced down? The effect seems to be rooted in the collective properties of ion channel assemblies [1]. Yet the apparently bistable dynamics of single ion channels implies, by analogy to familiar SR in double-well dynamics, the existence of SR on the level of these single membrane proteins. Nevertheless, in experiments such a single-molecular SR has not been reliably detected so far. Which essential features of the single ion channel dynamics can be responsible for the occurrence (or non-occurrence) of SR? A notrivial dependence of the mean closure time intervals on the voltage and temperature may delimit the regimes of occurrence and non-occurrence of SR even within the simplest two state Markovian setting [2]. Furthermore, non-Markovian effects can be of importance. I will discuss this complex issue within a sufficiently simple phenomenological framework of two state non-Markovian dynamics modeled by alternating renewal process.

[1] G. Schmid, I. Goychuk, P. Hänggi, Europhys. Lett. 56, 22 (2001)

[2] I. Goychuk, P. Hänggi, Phys. Rev. E 61, 4272 (2000)