Fig. 3. The GP-GP_o values of Laurdan in astrocyte membranes at 37°C. The GP-GP_o (GP_o is the GP of control sample without H₂O₂ treatment) increased with increasing concentration of H₂O₂ (2 hours treatment) (P<0.05), indicating that the plasma membranes became more gel-like. Pretreating astrocytes with the p38 MAPK inhibitor SB203580 (20 µM, 30 minutes) reduced the change in phase properties resulting from oxidative stress (P<0.05). Values are the mean ± s.d. of three independent experiments.