Organization and morphological characteristics of choline acetyltransferase-containing fibers in the visual thalamus and striate cortex of the cat.

The morphological characteristics and the distribution of cholinergic fibers in the cat visual system were studied with immunohistochemical methods employing monoclonal antibodies directed against choline acetyltransferase (ChAT). ChAT-positive fibers form dense meshworks within the main laminae of the dorsal lateral geniculate nucleus (LGNd), the perigeniculate nucleus (PGN) and the visual cortex. The fibers are of fine caliber, branch extensively and possess numerous varicosities in close contact with cellular elements. The density of ChAT + fibers is not uniform and is particularly high in cortical laminae I-III, the PGN complex and laminae A and A1 of the LGNd.