Regensburg 2007 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 16: Poster Session I
BP 16.57: Poster
Dienstag, 27. März 2007, 17:00–19:30, Poster D
Disordered ocular dominance maps by inter-map coupling — •Lars Reichl1,2, Siegrid Löwel3, and Fred Wolf1,2 — 1MPI für Dynamik und Selbstorganisation, Göttingen — 2Bernstein Center for Computational Neuroscience, Göttingen — 3Friedrich-Schiller-Universität , Jena
In the visual cortex of cats, orientation preference (OP) maps and ocular dominance (OD) maps are spatially irregular. Many models, e.g. [1], predict the formation of spatially periodic cortical maps. Recently it was found that irregular maps can be stabilized by long-range interactions in pattern formation models [2]. Because OD and OP maps are geometrically coupled, we studied whether such a coupling can transfer spatial irregularity from OP to OD maps. To this end we contructed dynamical pattern forming models in which we can continuously vary the strength of the inter-map coupling. The solutions of these models were investigated using coupled amplitude equations for the active Fourier modes of the two patterns. If the coupling enters at seventh order in these equations there is a limit in which the back-reaction of the OD dynamics onto the dynamics of the OP map is negligible. In the uncoupled case, OP maps are pinwheel rich and spatially aperiodic whereas OD maps consist of spatially periodic parallel stripes. Above a critical coupling strength the OD stripe solutions become unstable towards solutions showing a disordered layout. [1] Koulakov, Neuron 29, 519 (2001) [2] Wolf, PRL, 95:208701 (2005) [3] Hübener et al. J. of Neuroscience 17:9270 (1997)