Locomotor activity after D2DR and D1DR agonist administration in MsrA−/− and WT mice. Total distance traveled was measured for 45 min after intraperitoneal injections of saline (vehicle) or indicated drug. (a) Quinpirole injection at doses of 0.5 mg/kg and 0.1 mg/kg. WT, n = 7; MsrA−/−, n = 10. †p < 0.01 for quinpirole effect and *p < 0.02 for the genotype effect, determined by ANOVA. (b) SKF82958 injection at doses of 0.3 mg/kg and 1.0 mg/kg. WT, n = 7; MsrA−/−, n = 10. There was no significant effect of mouse type on SKF82958 effect, SKF82958 increased locomotor activity in the dose range used (†p < 0.01) and no dose-by-type interaction was detected; determined by ANOVA.