Influence of hydrocortisone, progesterone and testosterone on dendritic growth in vitro.

Explants from the temporal cortex of newborn Lewis rats were cultured in vitro in normal feeding medium and in nutrients enriched with hydrocortisone, progesterone and testosterone. The dendritic growth was estimated on the 7th, 14th and 21st day in the phase contrast microscope and finally on 28th day in the electron microscope. The explants which were cultured in a testosterone-enriched medium demonstrated a rapid and extensive dendritic growth and dendritic arborization. Neurons cultured in a progesterone-enriched medium demonstrated a marked dilatation of the cisternae of the smooth endoplasmic reticulum and a rather moderate dendritic growth and moderate synaptogenesis, whereas neurons cultured in a hydrocortisone-enriched nutrient exhibited an increase in the number of the free ribosomes, various mitochondrial alterations and a rather rapid dendritic growth and dendritic arborization as well as a large accumulation of glucogen granules.