Figure 1

Acquisition, extinction and reinstatement of WIN-induced CPP. Acquisition, extinction and reinstatement of WIN-induced CPP in three groups of animals: SAL, animals receiving saline in both compartments (n = 10); WIN 0.1, WIN 0.5, animals receiving 0.1 or 0.5 mg/kg of WIN in the drug-paired compartment (n = 10). The bars represent the mean (± SEM) time spent in the drug-paired compartment before conditioning sessions (white bars), after conditioning sessions (orange bars), in the last extinction session (light orange bars) and in the reinstatement test (brown). ** p < 0.02 significant difference in the time spent in pre-conditioning vs. post-conditioning sessions or reinstatement tests.