Differentiation of glioblasts from adult brain

Rat glial (RG) cells have established in continuous culture using sections of kainic acid-lesioned rat striata as the primary cell source. Such cultures consistently provided at least 2 morphologically distinguishable cell types. More than 95% of this population was composed of large, flat cells which possessed ill-defined junctions and lacked cellular processes. The second class of cells comprised less than 5% of the population, was smaller and had several processes per cell. Dibutyryl cyclic-AMP (dB-cAMP), which has been shown to promote a maturation-stimulating effect on embryonic glioblasts in vitro, appears to have a similar effect on RG cells. In the presence of 1 mM dB-cAMP virtually all RG cells undergo morphological transformation, becoming smaller and denser, in addition to forming several processes per cell. Furthermore, two cell-type-specific markers could be detected in dB-cAMP-treated cultures: the surface oligodendrocyte-specific galactocerebroside (GC) moiety was demonstrated to be present on less than 10% of the cells, whereas the intracellular astrocyte-specific glial fibrillary acidic (GFA) protein could be readily detected in 80% of the population. These data indicate that glia derived from the striata of injured adult rat brain exhibit fetal characteristics.