Effects of 31,345 and/or cocaine on extracellular NAc DA. (a) 31,345 (10 and 20 mg/kg, i.p.) produced a dose-dependent slow-onset (20–60 min) long-acting (at least 6–12 h) increase in NAc DA, whereas cocaine (10 mg/kg, i.p.) produced a robust rapid-onset short-duration increase in NAc DA. (b) The effect of 31,345 (10 and 20 mg/kg, i.p.) pretreatment on cocaine-enhanced extracellular NAc DA. (c) Renormalized cocaine-induced changes (percentage over new baseline immediately before cocaine administration) in NAc DA, as affected by 31,345 (10 and 20 mg/kg, i.p.) pretreatment. *p<0.05, **p<0.01, ***p<0.001, compared with baseline before cocaine or 31,345 administration (a) or before 31,345 (b) or cocaine (c) administration in each treatment group. #p<0.05, compared with 20 mg/kg 31,345 100 min post-cocaine.