(A) DAT-Smo ko mice showed an attenuated response to single methamphetamine challenge (2.5mg/kg). (**, p<0.01 and * p<0.05, Repeated measurement two way ANOVA, n= 8). (B) DAT-Smo ko mice showed attenuated locomotion activity in response to repeated methamphetamine injection in days during the development (D1,2,5) and the expression (challenge day 7 and d30) of sensitization (**, p<0.01 and * p<0.05 for Repeated measurement two way ANOVA, n= 8).