Basic fibroblast growth factor prevents ontogenetic neuron death in vivo.

Basic fibroblast growth factor (bFGF) is a mitogen and a potent neurotrophic protein for ciliary ganglionic (CG) neurons in vitro. Recombinant bFGF was administered to the chorionic-allantoic membrane of chick embryos during the period of ontogenetic neuron death in the cholinergic CG between embryonic days (E) 8 and E14. Neuronal losses in untreated chicks and in embryos that received the vehicle only (phosphate-buffered saline plus cytochrome c) amounted to 44%. Basic FGF permitted the survival of 87% of the neurons present at E8. There were no apparent differences in the size and number of non-neuronal cells in CG. These data add to the increasing body of evidence that bFGF is an important multifunctional growth factor with a neurotrophic capacity.