In vivo and in vitro NGF studies on developing cerebellar cells.

The biological effect of nerve growth factor (NGF) in the early prenatal cerebellar cell was studied in vivo and in vitro with autoradiographic, tissue culture and immunohistochemical techniques. Iodinated NGF (125I-NGF) injected into the cerebella of 16-day-old rat embryos showed accumulation of this ligand in the Purkinje cell layers. The ability of these cells to accumulate NGF lasted to the 19th day of embryonic life. Cerebellar cells isolated from embryos of the same age, but not older embryos, cultured in vitro for two weeks in the presence of NGF, showed morphological characteristics similar to Purkinje-like cells. These findings suggest that NGF exerts a time-limited trophic effect on immature Purkinje cell precursors.