For the CPP studies, alcohol was diluted from a 95% (v/v) solution to a concentration of 20% (v/v) with physiological saline (0.9%) and was administered intraperitoneally (IP) in a dose of 2.0 g per kilogram of body weight (g/kg; 0.06 g per 30 g body weight) and in an injection volume of 12.6 ml/kg. For the drinking study, alcohol was diluted from a 95% (v/v) solution to a concentration of 10% with tap water. Saccharin was added to both the alcohol and tap water drinking solutions at a concentration of 0.01% w/ v (Oberlin et al., 2010 (link)).
Rimonabant (Cayman Chemical, Ann Arbor, MI) was dissolved in 2 drops of Tween 80 and diluted with saline to the correct concentration to administer doses of 1 and 3 mg/kg, based on evidence that these doses effectively reduce alcohol intake in mice (Vinod et al., 2008 (link)). JWH-133 was received in Torcisolve (a water-soluble emulsion; Tocris Bioscience, Minneapolis, MN), diluted with saline, and administered in doses of 10 and 20 mg/kg, per Xi and colleagues (2011) (link). AM630 (Cayman Chemical) was diluted in DMSO (10%) and saline (90%) and administered in doses of 10 and 20 mg/kg (10 ml/kg injection volume) to match the doses of JWH-133. All control (vehicle) solutions were made of the same ingredients as the drug solution, without the drug.