Fig. 1
Pre-treatment with U50 on extinction day 1 reduces cue-induced reinstatement of cocaine seeking 2 weeks later. Following 2 weeks of cocaine self-administration and 7 days of home cage abstinence, rats (n = 7) were administered a single dose of U50 (5 mg/kg, i.p.) or VEH (n = 8) 30 min prior to the first extinction session. After extinction training was complete (10 sessions), rats underwent a cue-induced reinstatement test. U50 significantly reduced extinction responding on the first extinction session and 2 weeks later when challenged with cocaine cues (**p < 0.01 active lever, ++p < 0.01 inactive lever, comparing U50 to VEH)
