Figure 3.

Inhibition of p38 MAPK blocks growth factor-induced Schwann cell demyelination. A, Myelinated cocultures were treated with neuregulin or FGF2 (1 nm) + Forskolin (2 μm). Thirty-six hours later, demyelination was assessed by immunostaining for MBP. Treatment with SB203580 decreased growth factor-induced Schwann cell demyelination. *p < 0.01. B, SB203580 (7.5 μm) blocks neuregulin-induced p38 MAPK activation without affecting the other kinases. Fully myelinated cocultures were treated with neuregulin (1 nm) with or without SB203580. Eight hours later, various kinase activations were assessed by Western blot analysis. C, Images of MBP-positive myelin segments treated with FGF2 + Forskolin with or without SB203580 (7.5 μm). Scale bar, 50 μm.