Circuits for local and global signal integration in primary visual cortex

Publication Type Journal Article
School or College School of Medicine; College of Engineering
Department Ophthalmology; Bioengineering
Creator Angelucci, Alessandra; Lund, Jennifer S.
Other Author Levitt, Jonathan B; Walton, Emma J S; Hupe, Jean-Michel; Bullier, Jean
Title Circuits for local and global signal integration in primary visual cortex
Date 2002-10-01
Description Contrast-dependent changes in spatial summation and contextual modulation of primary visual cortex (V1) neuron responses to stimulation of their receptive field reveal long-distance integration of visual signals within V1, well beyond the classical receptive field (cRF) of single neurons. To identify the cortical circuits mediating these long-distance computations, we have used a combination of anatomical and physiological recording methods to determine the spatial scale and retinotopic logic of intra-areal V1 horizontal connections and inter-areal feedback connections to V1. We have then compared the spatial scales of these connectional systems to the spatial dimensions of the cRF, spatial summation field (SF), and modulatory surround field of macaque V1 neurons. We find that monosynaptic horizontal connections within area V1 are of an appropriate spatial scale to mediate interactions within the SF of V1 neurons and to underlie contrast-dependent changes in SF size. Contrary to common beliefs, these connections cannot fully account for the dimensions of the surround field. The spatial scale of feedback circuits from extrastriate cortex to V1 is, instead, commensurate with the full spatial range of center-surround interactions. Thus these connections could represent an anatomical substrate for contextual modulation and global-to-local integration of visual signals. Feedback projections connect corresponding and equal-sized regions of the visual field in striate and extrastriate cortices and cover anisotropic parts of visual space, unlike V1 horizontal connections that are isotropic in the macaque. V1 isotropic connectivity demonstrates that anisotropic horizontal connections are not necessary to generate orientation selectivity. Anisotropic feedback connections may play a role in contour completion.
Type Text
Publisher Society for Neuroscience
Volume 22
Issue 19
First Page 8633
Last Page 8646
Subject Primary Visual Cortex; Extrastriate Cortex; Feed-back Connections; Lateral Connections; SUrround Modulation; Macaque
Subject MESH Visual Cortex; Synaptic Transmission; Nerve Net
Language eng
Bibliographic Citation Angelucci A, Levitt JB, Walton EJ, Hupe JM, Bullier J, Lund JS. (2002). Circuits for local and global signal integration in primary visual cortex. J Neurosci, 22(19), 8633-46
Rights Management (c) Society for Neuroscience
Format Medium application/pdf (portable document)
Identifier ir-main,1704
ARK ark:/87278/s6tf0fg3
ID 702797
setname ir_uspace
Reference URL https://collections.lib.utah.edu/details?id=702797
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