Figure 3. p38MAPK activity increases in aged astrocytes and its expression is reduced with PH-797804. (A) Representative immunofluorescence and quantification for phosphorylated p38MAPK (P-p38MAPK) (green) together with DAPI (blue) and GFAP (red) in the cortex and in the DG of young (2 month-old) and aged (over 24 month-old) C57BL/6J mice (n=2). (B) Immunoblot of P-p38MAPK in 1DIV (young) and 30DIV (old) primary astrocyte cultures derived from Wistar rat brains. (C) Immunoblot of P-p38MAPK in old astrocyte cultures with and without PH-797804 treatment. (D) MAPK14 gene expression in old astrocyte cultures treated with PH-797804 at different time points in comparison to the control groups (without treatment) (n=6). Results are expressed as the mean ± SEM. Asterisks denote the significance levels when compared to the control group (***p<0.001, **p<0.01 and *p<0.05 versus controls, t-test).