Cortical connections of the visual pulvinar complex in prosimian galagos (Otolemur garnetti).

Bibliographic Collection: 
MOCA Reference, APE
Publication Type: Journal Article
Authors: Wong, P.; Collins, C. E.; Baldwin, M. K. L.; Kaas, J. H.
Year of Publication: 2009
Journal: J Comp Neurol
Volume: 517
Issue: 4
Pagination: 493-511
Date Published: 12/2009
Publication Language: eng
ISSN: 1096-9861
Keywords: Animals, Brain Mapping, Cholera Toxin, Pulvinar, Strepsirhini, Superior Colliculi, Visual cortex, Visual pathways, Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate

The pulvinar complex of prosimian primates is not as architectonically differentiated as that of anthropoid primates. Thus, the functional subdivisions of the complex have been more difficult to determine. In the present study, we related patterns of connections of cortical visual areas (primary visual area, V1; secondary visual area, V2; and middle temporal visual area, MT) as well as the superior colliculus of the visual midbrain, with subdivisions of the pulvinar complex of prosimian galagos (Otolemur garnetti) that were revealed in brain sections processed for cell bodies (Nissl), cytochrome oxidase, or myelin. As in other primates, the architectonic methods allowed us to distinguish the lateral pulvinar (PL) and inferior pulvinar (PI) as major divisions of the visual pulvinar. The connection patterns further allowed us to divide PI into a large central nucleus (PIc), a medial nucleus (PIm), and a posterior nucleus (PIp). Both PL and PIc have separate topographic patterns of connections with V1 and V2. A third, posterior division of PI, PIp, does not appear to project to V1 and V2 and is further distinguished by receiving inputs from the superior colliculus. All these subdivisions of PI project to MT. The evidence suggests that PL of galagos contains a single, large nucleus, as in monkeys, and that PI may have only three subdivisions, rather than the four subdivisions of monkeys. In addition, the cortical projections of PI nuclei are more widespread than those in monkeys. Thus, the pulvinar nuclei in prosimian primates and anthropoid primates have evolved along somewhat different paths.

DOI: 10.1002/cne.22162
Alternate Journal: J. Comp. Neurol.
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