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DY: Dynamik und Statistische Physik

DY 14: Statistical physics in biological systems I

DY 14.4: Vortrag

Montag, 24. März 2003, 15:30–15:45, G\"OR/226

What Determines the Timing of a Spike? — •Björn Naundorf, Fred Wolf, and Theo Geisel — Max-Planck-Institut für Strömungsforschung and Institut für Nichtlineare Dynamik der Universität Göttingen, Bunsenstr. 10, 37073 Göttingen, Germany

Neurons communicate by sending and receiving action potentials (spikes). These action potentials are generated in the soma, where under natural conditions the membrane potential (MP) changes constantly due to the time dependent inputs received by the neuron. While it is often assumed that a spike is emitted when the MP crosses a threshold voltage V_thres , neurons in vivo and biological sophisticated conductance based models behave differently. There, however, a thorough analysis of the underlying spike evoking mechanism is very involved. As a first approach we therefore propose a model in which a spike is emitted when the MP crosses a threshold in the V−V plane. In the low firing rate regime we determine the spike output rate analytically as a function of the statistical properties of the MP fluctuations. We verify the validity of our model with MP time series from neurons measured in vivo, as well as with numerically obtained time series from conductance based model neurons.