Effect of cytosine arabinoside on the composition of the nonneuronal cell population in cerebral explants

Abstract

Rat cortical explants were cultured in the presence or absence of the mitotic inhibitor cytosine arabinoside to determine whether or not it affects the composition of the nonneuronal cell population within the outgrowth zone. Ultrastructural morphometric analysis of the incidence of fibroblasts, fibrous astrocytes, and protoplasmic astrocytes-epithelial cells at 18 days in vitro, revealed statistically significant decreases in the incidence of fibroblasts and fibrous astrocytes in the explants treated with the inhibitor compared with control explants. Coupled with earlier findings of enhanced neurite outgrowth and decreased nonneuronal cell proliferation that follows such treatment, it appears that cytosine arabinoside may potentiate neurite outgrowth by altering the composition, as well as the number, of nonneuronal cells in the outgrowth zone. These data indicate that fibroblasts and fibrous astrocytes may limit the regenerative response of severed axons in the mammalian central nervous system.