Figure 4.

Conditioned place preference (CPP) to buprenorphine (BUP, 1 mg·kg⁻¹), BU10119 (1 mg·kg⁻¹) and morphine (10 mg·kg⁻¹). Two separate experiments were conducted. (A) BU10119 did not produce significant CPP. CPP to buprenorphine was not blocked in the presence of the irreversible μ antagonist CCAM (3 mg·kg⁻¹). (B) The activity of CCAM as a μ antagonist was confirmed by its ability to block morphine‐induced CPP. Data are presented as preference for drug‐paired side of CPP chamber, determined as the time spent in drug‐paired side (post‐conditioning) minus time spent in drug‐paired side pre‐conditioning (baseline). All data points are mean ± SEM. (A) *P < 0.05 compared to saline, n = 9 per treatment group. (B) *P < 0.05 compared to morphine, n = 8 per treatment group.