Figure 4

<p>Effect of media and growth factors on precursor cells. A; FGF2 increased neuronal differentiation compared to EGF. Precursor cells differentiated in the presence of re-introduced EGF and FGF were stained with β-III-tubulin four days after differentiation. B; Both FGF2 and EGF increased cell survival in the cultured compared to control. C; FGF showed a differential effect on β-III-tubulin-positive neuronal differentiation depending on the duration of the treatment. Short-term treatment led to increased numbers of β-III-tubulin positive neurons from precursor cells, whereas prolonged FGF led to a decrease. D, E; Serum increased neuronal differentiation in a dose-dependent manner. There was also a general increase in survival with increasing concentrations of B27 supplement. F, G; B27 and N2 had complementary effects on precursor cells. B27 increased the survival of the precursor cells, whereas N2 increased neural differentiation. H; Insulin alone was not sufficient to explain the effects of B27 or N2. I; Various neurotrophic factors had pronounced and differential effects on the precursor cells. BDNF, NT-3, Shh, VEGF, ECGF caused an increase in β-III-tubulin positive neurons. LIF and BMP showed potent pro-gliogenic effects. *, p<0.05; **, p<0.005; ***, p<0.0005