Induction of differentiation of rat retinal, germinal, neuroepithelial cells by dbcAMP

Little is known about the factors that regulate the production of neurons during the development of the vertebrate central nervous system (CNS); however, evidence from several neuronal cell lines suggests that an increase in intracellular cAMP might trigger the process of differentiation. To determine if a similar process is involved in differentiation during normal CNS neurogenesis, we raised the intracellular level of cAMP in primary cultures of mitotically active, germinal neuroepithelial cells from fetal and postnatal rat retina. This treatment induced differentiation of the CNS precursors, causing the cells to cease DNA synthesis and increase their expression of proteins normally found in differentiated retinal cells. These results indicate that germinal neuroepithelial cell differentiation can be controlled through the cAMP second messenger system, and that the regulation of this system may in part determine the numbers and ratios of the various classes of neurons during the normal development of the CNS.