CREB expression and phosphorylation in the CPu after single and repeated METH treatment.

<p>The mice were administered METH (1 mg/kg, i.p.) or saline once or received METH (1 mg/kg, i.p.) once every other day from Day 1 to Day 13 and challenged with saline or METH (1 mg/kg, i.p.) on Day 20 after a 7 day drug-free period. The mice were decapitated 1 h after the last METH or saline treatment. The blot density of each group was normalized to that of the wildtype saline group and is expressed as mean ± SEM (<i>n</i> = 6). <i>a</i>. METH-induced CREB expression in the CPu in wildtype mice (WT) and ICER I-overexpressing mice (Tg). *<i>p</i><0.05, significant difference in normalized CREB blot density compared with wildtype saline group. <i>b</i>. METH-induced CREB phosphorylation in the CPu in wildtype mice (WT) and ICER I-overexpressing mice (Tg). *<i>p</i><0.05, significant difference in normalized pCREB blot density compared with wildtype saline group.