Location and connections of visual cortical areas in the cat's suprasylvian sulcus

Abstract

The initial aim of the experiments described here was to identify and quantify the cortical and thalamic connections of visual cortical areas located in the vicinity of the suprasylvian sulcus. Inputs to various sites in this region were studied by making small injections of wheat germ agglutinin (conjugated to horseradish peroxidase) at physiologically identified locations. Retrogradely labeled cells were counted in each identifiable area of cortex and in thalamic nuclei. Some injections yielded quantitatively similar distributions of labeled cells, and it is suggested that such evidence provides a useful way of dividing the cortex into areas. By this criterion, a single, relatively large, cortical area was identified that occupied most of the medial bank of the suprasylvian sulcus, all or most of its posterior bank, and a small segment of its lateral bank. It was referred to as the Clare-Bishop area. Because neighboring visual areas were found to lack input from area 17, while the Clare-Bishop area received a strong striate input, its boundaries were investigated by labeling afferents from area 17. Together with the results of retrograde tracer injections, these data suggested that the Clare-Bishop area cuts across several of the visual areas defined physiologically by Tusa et al. ('81). As a consequence, its retinotopic organization must be relatively complex, with duplications of some parts of the visual field. Three other visual areas were tentatively identified on the basis of their distinctive connections. One was situated on the lateral bank of the suprasylvian sulcus and appeared to border the Clare-Bishop area laterally. Another, referred to as area 21, lay adjacent to area 19, and, for part of its length, also appeared to bound the Clare-Bishop area. The third, corresponding approximately to Heath and Jones's ('71) posterior suprasylvian region, lay lateral and anterior to the Clare-Bishop area in the depths of the posterior suprasylvian sulcus.

Neurons in V1, V2, and PMLS of Cat Cortex Are Speed Tuned But Not Acceleration Tuned: The Influence of Motion Adaptation

“…The lack of acceleration tuning in PMLS matches results from studies in MT, which failed to find evidence of acceleration tuning (Lisberger and Movshon 1999;Price et al 2005). Given the reciprocal anatomical connections among V1, V2 and PMLS (Norita et al 1996;Sherk 1986) and the fact that motion processing is performed synchronously in these brain areas (Dinse and Kruger 1994;Katsuyama et al 1996;Vajda et al 2000), it is logical that we found little evidence for acceleration tuning in V1 and V2.…”

Analysis of connectivity in the cat cerebral cortex

“…For example, Sherk (1986) and Grant and Shipp (1991) consider that PMLS and at least parts of VLS and AMLS belong to a single field, the Clare-Bishop area (Clare and Bishop, 1954;Hubel and Wiesel, 1969), while Symmonds and Rosenquist (1984a) and Palmer et al (1978) consider them distinct areas. Analysis, however, can itself inform this issue, since areas that have the same pattern of connections and, therefore, probably constitute a single functional field, will occupy identical positions in diagrams derived by NMDS.…”

A neurochemical signature of visual recovery after extrastriate cortical damage in the adult cat

“…The feline LS cortex is a complex of extrastriate visual areas (Palmer et al, 1978;Sherk, 1986b;Grant and Shipp, 1991;Sherk and Mulligan, 1993) that exhibit functional similarity with areas MT/MST of primates (Payne, 1993), playing an important role in the processing of complex visual motion information (Rauschecker, 1988;Rudolph and Pasternak, 1996;Akase et al, 1998). LS cortex is relatively high level in the hierarchy of the cat visual system (Scannell et al, 1995).…”

“…In the visual system, most studies reporting training-induced recovery of function were conducted following damage to extrastriate visual cortex-lesions of the lateral suprasylvian (LS) visual cortex in cats, e.g. (Rudolph and Pasternak, 1996 Pasternak, 2004) or lesions in areas MT/MST of monkeys (Newsome and Pare, 1988;Rudolph and Pasternak, 1999).The feline LS cortex is a complex of extrastriate visual areas (Palmer et al, 1978;Sherk, 1986b;Grant and Shipp, 1991;Sherk and Mulligan, 1993) that exhibit functional similarity with areas MT/MST of primates (Payne, 1993), playing an important role in the processing of complex visual motion information (Rauschecker, 1988;Rudolph and Pasternak, 1996;Akase et al, 1998). LS cortex is relatively high level in the hierarchy of the cat visual system (Scannell et al, 1995).…”