Effects of visual experience on the maturation of the efferent system to the corpus callosum

Abstract

IN normal adult cats the first and second visual areas (V1 and V2) in the two cerebral hemispheres are interconnected through the corpus callosum (CC) by neurones (callosal neurones) which have a characteristic laminar location and are restricted to the region of the boundary between cytoarchitectonic areas 17 (V1) and 18 (V2)1–4. Callosal neurones acquire this distribution postnatally by disappearing (dying, or eliminating their callosal connections) from most of areas 17 and 18 and decreasing in number in layer VI (refs 5, 6). Here we show that although kittens deprived of pattern vision by binocular lid suture still develop an apparently normal distribution of callosal neurones, monocularly deprived or enucleated, or bilaterally squinted kittens retain to adulthood some callosal neurones in parts of area 17 where such neurones are not normally found. Thus, visual experience can influence the selection of callosal neurones although this selection is probably influenced by more than one factor.