The effect of Y1R antisense (or missense) pretreatment on AMPH-induced changes of NPY, Y1R, c-Fos, and c-Jun levels over a 4-day period. Daily missense or antisense treatments (20 μg/10 μl/day, i.c.v.) were administered one hour before daily 4 mg/kg AMPH treatment. Results showed that Y1R antisense could partially restore c-Fos, and c-Jun levels toward normal. * p < 0.05 vs. the control (missense) groups of each treatment day. #p < 0.05 vs. the AMPH-treated groups of each treatment day. Bars are the means ± SEM. N = 8 per group.