Figure 2.

Survival of CG neurons in the presence of GDNF and TGFβ is mediated by activation of the ERK/MAPK pathway. (A) Simplified general scheme of GDNF signaling. (B) Survival of CG neurons in the presence of GDNF (10 ng/ml) and TGFβ3 (2 ng/ml), FGF-2 (10 ng/ml) or CNTF (10 ng/ml), respectively, in the absence or presence of the kinase inhibitors Wortmannin (100 nM), LY294002 (5 μM), U0126 (10 μM), and PD98059 (50 μM). The surviving neurons were counted after 24 h, each bar represents the mean and standard deviation of at least three independent experiments with every condition tested in triplicate per assay (***, P ≤ 0.01; **, P ≤ 0.05; *P ≤ 0.1). (C) Survival assay as described in (B) except that insulin (5 μg/ml) was added.