Abstract
We analyzed the molecular mechanisms
involved in the acquisition and maturation of
dopaminergic (DA) neurons generated in vitro
from rat ventral mesencephalon (MES) cells in the
presence of mitogens or specific signaling
molecules. The addition of basic fibroblast growth
factor (bFGF) to MES cells in serum-free medium
stimulates the proliferation of neuroblasts but
delays DA differentiation. Recombinant Sonic
hedgehog (SHH) protein increases up to three fold
the number of tyrosine hydroxylase (TH)-positive
cells and their differentiation, an effect abolished
by anti-SHH antibodies. The expanded cultures
are rich in nestin-positive neurons, glial cells are
rare, all