Projection of visuotopically organized afferents to the dorsal thalamus in the opossum, Monodelphis domestica

Abstract

Retrogradely transported dyes, Fluorogold and Fast Blue were injected into both sides of the dorsal thalamus in the Monodelphis opossum. Projection of the presumed primary visual cortical area, superior colliculus and parabigeminal nucleus to the dorsal lateral geniculate nucleus and the lateral posterior-lateral intermedius nuclear complex were described. They show close similarities to the homologous projections in the North American Opossum, insectivores and some rodents. In comparison with rat, cortico-thalamic and tecto-thalamic projections in the Monodelphis are less numerous. The peculiarity of cytoarchtitectonics of cortical layer 6 is described and discussed.