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SYPH: Physik im Hirn - Physical Approaches to Brain Function

SYPH 2: Physik im Hirn - Physical Approaches to Brain Function

SYPH 2.9: Poster

Donnerstag, 14. März 2002, 15:30–18:00, Poster D

Dynamics of Rate and Correlation in Cortical Feed-Forward Networks — •Tom Tetzlaff, Michael Buschermöhle, Theo Geisel, and Markus Diesmann — Dept. of Nonlinear Dynamics, MPI für Strömungsforschung, Göttingen

Experimental studies revealed that the cortical network can exhibit spatio-temporal spike patterns associated with sensory or contextual events (e.g. [1]). The concept of the synfire chain [2] explains how a state can arise in which dynamically grouped neurons discharge in precise coincidence. The excited mode of the underlying subnetwork is characterized by volleys of spikes stably propagating from one neuron group to the next [3]. In the ground state neurons asynchronously fire at low rates. From here the excited synchronous regime can be reached by increasing either firing rate or correlation inside the chain. The divergent/convergent network structure causes a strong coupling of both measures which can be captured in a 2-dimensional map simultaneously describing the spatial dynamics of rate and correlation. This framework enables us to discuss the stability of the ground state.

[1] Prut et al. (1998) J. Neurophysiol. 79:2857–2874
Abeles M. (1991) Corticonics
Diesmann et al. (1999) Nature 402:529–533