Figure 7.
Inhibition of endogenous neurotrophins, PI3-kinase, and MEK have similar effects in the absence of exogenous FGF2. a, Cortical progenitors were cultured for 2 d in the presence or absence of exogenous FGF2 (40 ng/ml), before analysis of apoptosis by TUNEL staining, proliferation by immunostaining for Ki67, or differentiation of neurons by immunocytochemistry forβIII-tubulin or MAP2. b, Cortical progenitors were treated with control IgY (40 μg/ml; IgY-Ctl), anti-NT-3 (20 μg/ml), or anti-BDNF (20 μg/ml) in the absence of exogenous FGF2 for 2 d before analysis similar to that shown in a. Graphs are representative results from one of three independent experiments. c, Cortical progenitors were treated with DMSO (1%), PD98059 (50 μm; PD), or LY294002 (50–100 μm; LY) for 2 d in the absence of exogenous FGF2 before analysis as in a. Graphs are representative results from one of three independent experiments. In all three panels, **p < 0.01; ***p < 0.001 (Student's t test in a; ANOVA in b and c). Error bars indicate SDs.