The effect of dibutyryl cyclic AMP on cultivated glial cells from corpus callosum of 30-day-old rats.

1. Fragments of corpus callosum of 30-day-old rats were cultivated in Rose chambers. Mature astrocytes and predominantly differentiated oligodendroglial cells are present in the corpus callosum of rats at this age. 2) In vitro, astrocytes dedifferentiated into epithelial--like flattened cells, which highly adhered to the surface. Cells exhibited signs of phagocytosis, and their ultrastructure differed from differentiated cells, especially by the absence of microtubules and microfilaments. 3) After dibutyryl cyclic AMP (db-c-AMP) application, epithelial--like cells became rounded and multipolar. Cells were less liable to adhere to the surface. Bundles of microfilaments and microtubules appeared in cell perikarya and their processes. 3--4 hour after application, the morphological changes were well developed and disappeared after 24--48 hours. 4) It is being suggested that the increased intracellular concentration of db-c-AMP induced the formation of microfilamentous structures. The formation of the cyto-skeleton has a direct influence on the shape of cells and appearance of processes and cell adhesivity. 5) These results have demonstrated the high structural plasticity of mature astrocytes, their dedifferentiation in vitro and convertion into mature cells after db-c-AMP application.