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DY: Dynamik und Statistische Physik

DY 43: Signals and neuronal Networks

DY 43.4: Vortrag

Donnerstag, 30. März 2006, 12:15–12:30, SCH 251

Influence of negative feedback on the dynamics of a stochastic signalling module — •Peter Borowski, Manoj Gopalakrishnan, Frank Jülicher, and Martin Zapotocky — Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden

We study the stochastic kinetics of a two-state signalling module. In the active state, the module produces a chemical species which enhances the rate of deactivation, giving raise to negative feedback. Examples are an ion channel whose closing rate depends on the ion concentration that it conducts, or a gene whose protein product acts as a repressor. We develop a path-integral formulation of the two-state process, based on the temporal statistics of its state-flips. In the limit of weak feedback, analytic results are obtained for the mean values and correlationfunctions as well as response functions. Monte Carlo simulations are performed which support these analytical predictions and provide results beyond linear perturbation theory.