Transplantation of fetal and early postnatal rat septal cholinergic neurons cultured in serum-free and serum-containing medium with nerve growth factor.

Fetal rat (E17-E19) septal neurons were cultured in a defined, serum-free medium for 6-8 days with or without nerve growth factor (NGF) and transplanted into the hippocampus or the surrounding ventricle of 28 adult rats denervated of its septal input by a fimbria-fornix transection. The cholinergic septal neurons, which were visualized by acetylcholinesterase (AChE) histochemistry, always survived in transplantation to the adult brains from nearly pure neuronal cultures. Although choline acetyltransferase (ChAT) activity of septal neurons in culture was greatly increased (5.59-fold) by the addition of NGF to the defined medium, this ChAT induction appeared to have little effect on the subsequent survival or growth of the septal neurons after transplantation. These results demonstrate that survival of cultured fetal septal cholinergic neurons following transplantation is not dependent upon the presence of NGF or serum- or glia-derived factors during the preliminary culture. Postnatal rat (P4) septal neurons cultured for 5 days in serum-containing medium with NGF were also successfully transplanted in one of 3 cases.