NEUROCHEMICAL GRADIENT ALONG THE MONKEY OCCIPITOTEMPORAL CORTICAL PATHWAY

WE have examined the neuronal distribution of two calcium-binding prot eins, calbindin (CB) and parvalbumin (PV), along the occipito-temporal cortical pathway, which sequentially connects visual areas V1, V2, V4 , TEO, and TE, and then areas TG and 36 in monkeys. Immunohistochemica l staining showed that CB-containing pyramidal cells, which were mostl y limited to layers 2 and 3, gradually increased in population from th e posterior to the anterior areas. PV-containing non-pyramidal cells w ere sparser in areas TG and 36 than in the other areas. The posterior and anterior areas of the occipito-temporal cortical pathway are diffe rent in the chemical characteristics of their neurones.