STEM-CELL FACTOR IS A NEUROTROPHIC FACTOR FOR NEURAL CREST-DERIVED CHICK SENSORY NEURONS

We have found that stem cell factor (SCF) selectively enhances the sur vival of cultured embryonic chick dorsal root ganglia (DRG) neurons. N eurons grown in the presence of SCF expressed both neurofilament 150 k Da subunit and calcitonin-gene related peptide. SCF does not, however, enhance the survival of parasympathetic, placode-derived sensory or s ympathetic neurons in culture. Combining SCF with brain-derived neurot rophic factor or neurotrophin-3, but not with NGF, maintains more neur ons than either factor alone, suggesting that these factors have parti ally overlapping activities. SCF preferentially rescues small neurons from the DRG. Labeling studies with bromodeoxyuridine indicate that th e neurons sustained by SCF are not differentiating from a dividing pro genitor.