Nerve Growth Factor Requirement of Postnatal Rat Adrenal Medullary Cells in vitro for Survival, Aggregate Formation and Maintenance of Extended Neurites

Rat adrenal medullary cells, taken at different postnatal stages (1, 4, 10 and 14 days), were cultured in serum-containing medium with and without nerve growth factor (NGF 2.5 S, 50 ng/ml) to investigate their dependence on NGF for survival and maintenance of extended neurites. It was found that medullary cells depend on NGF for survival at day 1 and, to a lesser extent, at day 4. Neurite-like processes extended in response to NGF treatment breakdown when NGF is withdrawn. NGF-treated adrenal medullary cells displayed a pronounced tendency to form aggregates. It was also shown that plating adrenal medullary cells at higher cell densities, which largely increased the numbers of fibroblast-like cells present, may substitute for NGF with respect to survival.