title: Lateral connectivity and contextual interactions in macaque primary visual cortex.
abstract: Two components of cortical circuits could mediate contour integration in primary visual cortex (V1): intrinsic horizontal connections and feedback from higher cortical areas. To distinguish between these, we combined functional mapping with a new technique for labeling axons, a recombinant adenovirus bearing the gene for green fluorescent protein (GFP), to determine the extent, density, and orientation specificity of V1 intrinsic connections and V2 to V1 feedback. Both connections cover portions of V1 representing regions of visual space up to eight times larger than receptive fields as classically defined, though the intrinsic connections are an order of magnitude denser than the feedback. Whereas the intrinsic connections link similarly oriented domains in V1, V2 to V1 feedback displays no such specificity. These findings suggest that V1 intrinsic horizontal connections provide a more likely substrate for contour integration.
authors.affiliation: The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
authors.forename: Dan D
authors.initials: DD
authors.lastname: Stettler
authors.forename: Aniruddha
authors.initials: A
authors.lastname: Das
authors.forename: Jean
authors.initials: J
authors.lastname: Bennett
authors.forename: Charles D
authors.initials: CD
authors.lastname: Gilbert
mesh_terms: D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001369:Axons / Q000502:physiology / Q000648:ultrastructure*; D001931:Brain Mapping; D023882:Dominance, Ocular / Q000502:physiology; D005246:Feedback / Q000502:physiology; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D007091:Image Processing, Computer-Assisted; D008164:Luminescent Proteins; D008252:Macaca fascicularis; D008253:Macaca mulatta; D018613:Microscopy, Confocal; D009434:Neural Pathways / Q000166:cytology* / Q000502:physiology; D010364:Pattern Recognition, Visual / Q000502:physiology*; D014793:Visual Cortex / Q000166:cytology* / Q000502:physiology; D014794:Visual Fields / Q000502:physiology
chemical_list: D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins