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Thalamocortical NMDA conductances and intracortical inhibition can explain cortical temporal tuningCells in cerebral cortex fail to respond to fast-moving stimuli that evoke strong responses in the thalamic nuclei innervating the cortex. The reason for this behavior has remained a mystery. We study an experimentally motivated model of the thalamic input-recipient layer of cat primary visual cortex that accounts for many aspects of cortical orientation tuning. In this circuit, inhibition dominates over excitation, but temporal modulations of excitation and inhibition occur out of phase with one another, allowing excitation to transiently drive cells. We show that this circuit provides a natural explanation of cortical low-pass temporal frequency tuning, provided N-methyl-D-aspartate (NMDA) receptors are present in thalamocortical synapses in proportions measured experimentally. This suggests a new and unanticipated role for NMDA conductances in shaping the temporal response properties of cortical cells, and suggests that common cortical circuit mechanisms underlie both spatial and temporal response tuning.
Document ID
Document Type
Reprint (Version printed in journal)
External Source(s)
Krukowski, A. E. (University of California San Francisco, California 94143-0444, United States)
Miller, K. D.
Date Acquired
August 21, 2013
Publication Date
April 1, 2001
Publication Information
Publication: Nature neuroscience
Volume: 4
Issue: 4
ISSN: 1097-6256
Subject Category
Life Sciences (General)
Funding Number(s)
Distribution Limits