Fig 1. Administration of the highest indomethacin dose before each social defeat blocked acquisition of the CPP induced by 1 mg/kg of cocaine in defeated mice.

Before the social stress protocol animals were randomly assigned to the following groups according to the pre-treatment they received: saline (EXP-SAL n = 13; RSD-SAL n = 14); 5 (RSD-INDO5 n = 16) or 10 mg/kg (EXP-INDO10 n = 13; RSD-INDO10 n = 17) of indomethacin. Bars represent the time (s) spent in the drug-paired compartment before conditioning sessions in the PRE-C test (white bars), after conditioning sessions in the POST-C test (dark grey bars), in the last extinction (EXTINCT) session (light gray bars), and in the reinstatement (REINST 0.5) test (black bars). Data presented as mean values ± SEM *p <0.05, ***p <0.001 significant difference in the time spent in the drug-paired compartment versus PRE-C.