The Bernstein Center Freiburg

Informal Seminar
Alexander Rothkegel

Dept. of Epileptology, Neurophysics Group, University of Bonn
Helmholtz-Institute for Radiation and Nuclear Physics, University of Bonn
Interdisciplinary Center for Complex Systems, University of Bonn

Small-world networks of
excitable integrate-and-fire neurons
Tuesday, January 26, 2010
14:00 h sharp
Library, first floor
BCCN Building
Hansastr. 9a
We investigate the collective dynamical behavior of pulse-coupled, excitable integrate-and- fire neurons that are arranged on a two-dimensional small-world network. We study network dynamics evolving from different sets of initial conditions in dependence on coupling strength and rewiring probability. Besides a homogeneous equilibrium state for low coupling strength, we observe different local patterns including cyclic waves, spiral waves, and turbulentlike patterns, which - depending on network parameters - interfere with the global collective firing of neurons. In addition, we observe chimera-like states, where the network separates into synchronous and asynchronous parts. We attribute the various network dynamics to distinct regimes in the parameter space and discuss how the different network dynamics may relate to pathophysiological processes in the brain such as epileptic seizures.
The talk is open to the public. Guests are cordially invited!