Effect of dAAO on CREB, ERK1/2, and GSK‐3β phosphorylation. After incubation with dAAO for 3 h, ERK1/2 phosphorylation significantly restrained (B). Six h after dAAO treatment, CREB phosphorylation (A) and GSK‐3β phosphorylation (C) remarkably decreased, and the suppression continued until 48 h. n = 4. *P < 0.05; **P < 0.01 as compared with the control group.