Western blot analysis for phosphorylation of CREB and the different MAP kinases in hippocampal neurons. Cultured hippocampal neurons were treated with IL-1β (10 ng/ml) for the indicated times, lysed, and analyzed by Western blot for P-CREB (A), P-JNK (B), P-ERK (C), or P-p38 (D). Blots were stripped and reprobed for total CREB (A), JNK (B), and p38 (D) or ERK (data not shown because no differences in P-ERK were seen).