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A model of ocular dominance column development by competition for trophic factor

Proceedings of the National Academy of SciencesPublished 2 September 1997Open access
Anthony E. Harris, G. Bard Ermentrout, Steven L. Small
Citations51
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TL;DR

A model of OD column development is presented, incorporating Hebbian synaptic modification and activity-driven competition for NT, which accounts for both normal OD columndevelopment as well as the prevention of that development when competition is removed.

Abstract

Recent experimental evidence has shown that application of certain neurotrophic factors (NTs) to the developing primary visual cortex prevents the development of ocular dominance (OD) columns. One interpretation of this result is that afferents from the lateral geniculate nucleus compete for postsynaptic trophic factor in an activity-dependent manner. Application of excess trophic factor eliminates this competition, thereby preventing OD column formation. We present a model of OD column development, incorporating Hebbian synaptic modification and activity-driven competition for NT, which accounts for both normal OD column development as well as the prevention of that development when competition is removed. In the "control" situation, when available NT is below a critical amount, OD columns form normally. These columns form without weight normalization procedures and in the presence of positive inter-eye correlations. In the "experimental" case, OD column development is prevented in a local neighborhood in which excess NT has been added. Our model proposes a biologically plausible mechanism for competition between neural populations that is motivated by several pieces of experimental data, thereby accounting for both normal and experimentally perturbed conditions.

Keywords

NeuroscienceBiochemistry, Genetics and Molecular Biology