Complementary distributions of calbindin, parvalbumin and calretinin in the cerebellar vermis of the adult cat.

Abstract

Immunocytochemistry was used to compare regional and cellular distribution of the calcium-binding proteins calbindin (CB), parvalbumin (PV) and calretinin (CR) in the cerebellar vermis of adult cats. CB and PV displayed similar patterns of distribution, mainly in Purkinje cells and their processes. Immunoreactive Purkinje cell axons were organised in bundles alternating with reaction-free strips, or raphes, of afferent fibres. In contrast, CR immunoreactivity was most apparent in unipolar brush neurons, and in mossy and climbing fibres. CR positive unipolar brush neurons were clustered and positive climbing fibres formed bands. Thus, CR was associated with afferent fibres and interneurons, and occurred in complementary structures to those demonstrated for CB and PV, mainly in efferent neurons and pathways.