Intermediate filament proteins in mouse brain cells cultured in the presence or absence of fetal calf serum

Abstract

Mesencephalic cells from 13-day-old mouse embryos were cultured either in the presence of serum or in a conditioned chemically defined medium. The types of intermediate filaments present in the cells in these two conditions were analysed by immunocytochemical means. It was found that in the absence of serum more than 95% of the cells contained neurofilaments and were therefore neuronal in nature. The remaining 5% were all stained with an antibody against vimentin. In the presence of serum the proportion of vimentin-positive cells increased very much. Double labelling experiments were performed in order to further characterize the vimentin-containing cells. It was found that 30–50% of these cells also contained the glial fibrillary acidic protein and were therefore likely to be astrocytes. No cell ever reacted with antigalactocerebrosides or antibodies against fibronectin excluding the presence or fibroblasts or mature oligodendrocytes in these cultures.