The retinotopic organization of area 17 (striate cortex) in the cat

TLDR

The study reports the retinotopic organization of cortical area 17 in cats. The authors mapped visual cortex in over 100 cats, relating receptive field positions of neurons to recording sites to delineate area 17’s retinotopic layout. Area 17 offers a single, contiguous representation of the entire visual field, has the largest cortical surface area and highest magnification factor among studied areas, its electrophysiological borders align perfectly with cytoarchitectural borders, and shows some inter‑cat variability in extent and retinotopic mapping.

Abstract

Abstract The location and retinotopic organization of visual areas in the cat cortex were determined by systematically mapping visual cortex in over 100 cats. The positions of the receptive fields of single neurons or small clusters of neurons were related to the locations of the corresponding recording sites in the cortex to determine the representations of the visual field in these cortical areas. In this report, the first of a series, we describe the organization of area 17. A single representation of the cat's entire visual field corresponds closely to the cytoarchitectonically defined area 17. This area has the largest cortical surface area (380 mm 2 ) and the highest cortical magnification factor (3.6 mm 2 /degree 2 at area centralis) of all the cortical areas we have studied. There was perfect agreement between the borders of area 17 determined electrophysiologically and cytoarchitecturally. This area contains a first order transformation of the visual hemifield in which every adjacent point in the visual field is represented as an adjacent point in the cortex. Some variability exists among cats in the extent and retinotopic representation of the visual field in area 17.