Organization of visual corticostriatal projections in the cat, with observations on visual projections to claustrum and amygdala

Abstract

Electrophysiological mapping criteria were employed to identify visual areas 20a, 20b, 21a, 21b, PMLS, AMLS, ALLS, PLLS, DLS, VLS, and PS in the cat, and to guide placement of tracer deposits. Anterograde tracer methods were used to study the corticostriatal projections of these extrastriate visual areas. The experiments demonstrate that all 11 extrastriate areas send projections to two distinct regions within the striatum, an extensive longitudinal zone within the caudate nucleus, and a more compact region within the posterolateral putamen. Cortical visual projections to the putamen terminate in relatively compact sheets or slabs, and appear to overlap extensively, while those to the caudate nucleus are irregularly patchy and more widely dispersed. Retrograde tracer deposits into the visual recipient zone of the caudate nucleus reveal substantial convergence of other cortical inputs to this same domain. Aspects of visuotopic organization are preserved in the visual projections to both the putamen and the caudate nucleus, but unequivocal retinotopic organization could not be inferred from the available material. Ten of the eleven extrastriate visual area also project topographically onto the visual zone of the claustrum. Area PS does not appear to contribute to the corticoclaustral projections. Five of the extrastriate visual areas (ALLS, PLLS, DLS, VLS, PS) also send sparse projections to the amygdaloid complex.

Response Properties of Corticotectal and Corticostriatal Neurons in the Posterior Lateral Suprasylvian Cortex of the Cat

“…These findings parallel anatomical demonstrations that corticotectal and corticostriatal neurons are distinguishable based on the sizes of their somas and their sublaminar distributions. They are also consistent with the absence of double-labeled LS neurons after injections of different retrograde tracers in the superior colliculus and caudate nucleus (Rhoades et al, 1982;Segal and Beckstead, 1984;Norita et al, 1991;McHaffie et al, 1993a;Updyke, 1993). Partic- (n ϭ 12) (n ϭ 10) PL L S 11 9.5 Ϯ 6.9 1847 Ϯ 1929 11 9 (82%) 0.22 Ϯ 0.12 209 Ϯ 77 (n ϭ 11) (n ϭ 11) (n ϭ 10)…”

“…This corticotectal bias has an obvious parallel in the expanded representation of central visual space in the superior colliculus (Feldon et al, 1972). The fact that no corticostriatal neurons were found in the most caudal aspects of PML S or PL L S, where the area centralis is represented (Palmer et al, 1978;Grant and Shipp, 1991), is consistent with the observation that this region sends only sparse projections to the caudate nucleus (Updyke, 1993), and the coarse visuotopy along the horizontal meridian observed in the caudate (Updyke, 1993) may reflect, in part, the comparatively larger receptive fields of corticostriatal neurons in L S.…”

“…A linear array of four varnish-coated, tungsten monopolar stimulating electrodes (tip exposure, 150 -300 m; electrode separation, 1 mm) oriented rostral to caudal was lowered into the left superior colliculus to a point 2 mm below the first site at which vigorous visual responses were initially recorded. T wo such electrode arrays were also stereotaxically implanted in the left caudate nucleus [Horsley -C lark coordinates, anterior (A) 12.0 to A15.0, lateral (L) 4.5, and height (H) 6.2; A12.5 to A15.5, L5.5, and H4.7], spanning the area where dense terminal labeling could be seen after L S cortical injections (Norita et al, 1991;McHaffie et al, 1993b;Updyke, 1993). Each of these electrode arrays was used to antidromically activate corticof ugal neurons.…”

“…Both the direct and presumptive indirect corticotectal pathways arise from neurons interspersed along the medial and lateral banks of the posterior regions of the LS (Kawamura et al, 1978;Battaglini et al, 1982;Berman and Payne, 1982;Baleydier et al, 1983;Segal and Beckstead, 1984;Burchinskaya et al, 1988;Norita et al, 1991;Updyke, 1993). LS targets regions in the striatum that project, in turn, to regions of the substantia nigra (Royce and Laine, 1984) that connect to the superior colliculus (i.e., via nigrotectal projections; for review, see Harting et al, 1988).…”

Role of the Claustrum in Convulsive Evolution of Visual Afferent and Partial Nonconvulsive Seizure in Primates

“…Furthermore, the CL has widespread reciprocal connections with the cerebral cortex, including the visual (7,(12)(13)(14)(15)(16)(17)(18)(19)(20), cingulate (15,(17)(18)(19)24), and motor cortices (1521-28); the AM (12,29,30); the basal ganglia (31)(32)(33)(34); and other subcortical structures (35)(36)(37)(38)(39); it also projects to the midbrain (40,41). Therefore, the CL appears to be strategically located for organized interaction between the specific visual pathway, the AM, the CG, and the cerebral motor mechanism.…”