The Bernstein Center for Computational Neuroscience Freiburg


Announcement for the next
Informal Seminar
Moritz Deger
Neurobiology and Biophysics
Institute of Biology III
University of Freiburg, Germany
SELF-ORGANIZATION OF CONNECTIVITY IN CORTICAL NETWORKS, BASED ON STRUCTURAL PLASTICITY

Tuesday, March 10th, 2009
9:15 h sharp
Room 05.070, 5th floor
Institute of Biology III
Schänzlestr. 1
Abstract:
We study recurrent neural networks exhibiting structural plasticity by formation and elimination of synapses: synaptic death is controlled by a biologically realistic correlation dependent learning rule [1] and synapse formation with a fixed rate takes place in a random manner. The interplay between network dynamics and correlation dependent evolution of network structure exhibits an interesting feature: We observe the emergence of cell assemblies in initially random cortical networks upon correlated stimulation of a subgroup of neurons. To gain a quantitative understanding, we reduce the detailed spike based learning dynamics to effective rate equations where the network dynamics follows the structure adiabatically. We show that this description captures the essential features of the interplay between structural plasticity and network dynamics. Comparison to direct numerical simulations proves the approximate procedures applied on many levels adequate. [1] Moritz Helias, Stefan Rotter, Marc-Oliver Gewaltig, and Markus Diesmann. Structural plasticity controlled by calcium based correlation detection. 2008. accepted.
The talk is open to the public. Guests are cordially invited!
www.bccn.uni-freiburg.de