Fig. 5.

Schwann cell survival promoted by GGF requires PI 3-kinase. Schwann cells were cultured for 3 d in either serum-containing media (Ctrl) or serum-free media (SFM). In some cultures, the serum-free media were supplemented with 4 μm forskolin and 50 ng/ml GGF, without (GGF) or with 20 μmLY294002 (LY20) or 10 μm U0126 (U10). Apoptotic cells were detected by the TUNEL assay. Values represent the mean BrdU index ± SEM from three separate experiments.