Effect of NAc core MeCP2 knockdown on METH SA, extinction, and reinstatement. (a) Average number of infusions per 6-h METH SA (0.05 mg/kg/infusion) session in sh-Control (n=8) and sh-MeCP2 (n=9). Average number of operant responses (b) and infusions (c) earned under a progressive ratio schedule of METH reinforcement (0.05 mg/kg/infusion). Sessions were terminated when no infusions were earned for 2 h. sh-Control (n=6) and sh-MeCP2 (n=9). *p<0.05 vs sh-Control. (d) Average number of active responses during the last 2 days of both SA (ie, SA Baseline) and Extinction, and during METH-primed Reinstatement in sh-Control (n=5) and sh-MeCP2 (n=8) infused rats. For METH-primed reinstatement, rats received METH injections (1 mg/kg, i.p.) 15 min prior to placement in the operant chamber. *p<0.05 vs sh-Control.+p<0.05 vs SA Baseline. #p<0.05 vs Extinction. Error bars indicate SEM.