Rats were tested for conditioned place preference on day 1 (pre-exposure), followed by a conditioning period with i.p. injections of either saline (sal) or cocaine (coc, 15 mg/kg) until day 8, as indicated (lower panel). Vehicle (veh) or SR 48692 (SR, 1 mg/kg) were administered i.p. from day 9 to day 18. A cocaine challenge (15 mg/kg, i.p.) was then applied on day 18, and CPP was assessed on day 19. The coc+veh (n=14) and coc+SR (n=14) groups received cocaine on days 2, 4, 6, 8, 18 and saline on days 3, 5, 7, 17. The sal+veh (n= 14) and sal+SR (n=13) groups always received saline instead of cocaine. Data represent means ± SEM of time spent in drug-paired compartment. ***: P < 0.001 vs. sal+veh-treated rats; #: P < 0.05 vs. coc+veh-treated rats (two-way ANOVA, Newman-Keuls).