Effects of YQA14 on basal level of locomotion and cocaine-induced behavioral sensitization. A: Pretreatment of YQA14 (12.5, 25 mg/kg, i.p., 20 min prior to each cocaine injection) did not produce a statistically significant inhibition on acquisition of cocaine-induced locomotor sensitization. Repeated administration of YQA14 (25 mg/kg) alone also failed to alter basal levels of locomotion. B: A single injection of YQA 14 (12.5, 25 mg/kg, i.p.) significantly inhibited expression of cocaine-induced locomotor sensitization in rats 7 days after the last cocaine injection.