Portal de Periódicos da CAPES

Lamination of the dorsal lateral geniculate nucleus in carnivores of the weasel ( Mustelidae ), Raccoon ( Procyonidae ) and Fox ( Canidae ) families

1974; Wiley; Volume: 153; Issue: 3 Linguagem: Inglês

10.1002/cne.901530303

1096-9861

K.J. Sanderson,

melanin and skin pigmentation

Abstract The laminar structure of the dorsal lateral geniculate nucleus was studied in carnivores of the weasel, raccoon and fox families. All have the same basic pattern of laminar organization in their lateral geniculate nuclei. Laminae A and C receive a contralateral projection from the retina and laminae A1 and C1 receive an ipsilateral projection. It is not known whether lamina C2 receives a retinal projection. There are some variations to the basic pattern of laminar organization. Thus, in the mink and weasel laminae A and A1 are each subdivided into a pair of separate but similar leaflets. In the ferret and coatimundi these laminae are only partly subdivided. In the skunk, raccoon, ringtailed cat and fox there is only one lamina A and one lamina A1 in each lateral geniculate nucleus. There is some variation of the C laminae also. The C laminae are best displayed in the fox, where all three laminae — C, C1 and C2 — can be recognized in Nissl sections. In other carnivores, for example the mink and ferret, the C laminae cannot be distinguished from each other in normal brains and are described on the basis of the degeneration that is seen in Nauta and Fink‐Heimer sections after a unilateral enucleation. In the raccoon lamina C can be identified but lamina C1 may be missing. The perigeniculate nucleus is variable in structure in carnivores. In the weasel and raccoon family the perigeniculate nucleus is a thick layer containing many large cells while in the cat and fox, it is a thin and rather diffuse group of cells. The perigeniculate nucleus may receive a direct retinal projection but if so, it is only a very sparse one.