Journal of Neuroscience, Vol 12, 4195-4201, Copyright © 1992 by Society for Neuroscience
Fibroblast growth factor differentially modulates the neurotransmitter phenotype of cultured sympathetic neurons
A Zurn
Division of Neuropathology, Institute of Pathology, Lausanne, Switzerland.
Fibroblast growth factors (FGFs) are multifunctional growth factors that
increase the proliferation of mesoderm- and neuroectoderm-derived cells and
promote neuronal survival and neurite outgrowth in various regions of the
brain, yet the physiological role(s) they may play in nervous system
function and/or development is unclear. The present report demonstrates,
using a well-characterized system, avian sympathetic neurons in vitro, that
acidic and basic FGFs increase ChAT but decrease tyrosine hydroxylase (TH)
activity in these cells, without affecting neuronal growth and survival.
Heparin, which binds to FGFs with a high affinity, potentiates the activity
of FGF on ChAT, but not TH. The time course of FGF action on the
neurotransmitter phenotype is slow since effects start to appear after 1-2
d only. FGFs may thus modulate the activities of ChAT and TH by
differentially regulating the expression of the genes coding for these
enzymes. In conclusion, this report provides evidence supporting the
hypothesis that FGFs may play a role in regulating neurotransmitter
expression in sympathetic neurons during development independently of any
effect on neuronal survival.