Thalamic afferents to the visual cortex in the cat studied by retrograde axonal transport of horseradish peroxidase.

Thalamic projections to visual areas 17, 18 and 19, neighboring suprasylvian cortex have been studied using the HRP method. Area 17 receives fibers mostly from the main laminae of the dorsal lateral geniculate nucleus (GLd). Area 18 receives inputs mainly from the central and medial interlaminar nuclei (NIC, NIM), and partly from laminae of GLd. Area 19 receives fibers principally from lamina B (C1-C2) and NIM of GLd. In addition, areas 17, 18 and 19 receive a few fibers from extrageniculate thalamic nuclei, particularly the pulvinar and intralaminar nuclei.