R baclofen hydrochloride

R(+)-baclofen hydrochloride (Sigma-Aldrich, St. Louis, MO, USA) was injected intraperitoneally (i.p.) 30 min before testing. CGP44532 was kindly donated by Novartis Pharma AG, and was injected subcutaneously (s.c.), 15 min before testing. Buspirone hydrochloride (Sigma-Aldrich) was injected s.c., 10 min before testing. All of the above compounds were dissolved in sterile 0.9% saline and injected in a volume of 1 ml/kg. BHF177 was synthesized as described previously (Li et al., 2013 (link)). BHF177 was suspended in 0.5% methylcellulose and administered orally (p.o.) in a volume of 2 ml/kg, 1 hr before testing. Rats were fasted for approximately 12 to 16 hrs before p.o. administration of BHF177. The doses of baclofen (0.4, 0.9 and 1.25 mg/kg) were chosen based on previously published studies (Cryan et al., 2004 (link); Frankowska et al., 2007 (link)). The doses of CGP44532 (0.065, 0.125 and 0.25 mg/kg) and BHF177 (10, 20, and 40 mg/kg) were chosen based on previous studies in our laboratory and others (Maccioni et al., 2009 (link); Paterson et al., 2008 (link); Vlachou et al., 2011a (link); Vlachou et al., 2011b (link)). The doses of buspirone (1 and 3 mg/kg) were chosen based on previous publications (Brodkin et al., 2002 (link); Commissaris et al., 2004 (link)).

Acamprosate calcium (Tocris, Minneapolis MN), R(+)-baclofen hydrochloride (Sigma-Aldrich, St. Louis MO) and naltrexone HCl (Sigma-Aldrich) were dissolved in normal saline, which served as the vehicle. Drugs or vehicle were administered by intraperitoneal injection at a volume of 0.1 ml/10 g body weight. For the DID tests, ethanol (200 proof, Decon Labs, King of Prussia, PA) was dissolved in tap water (20% v/v). In some experiments, saccharin sodium salt hydrate (Sigma-Aldrich) was dissolved in tap water to a concentration of 9.2 mM and offered as a drinking solution. Because of the more limited clinical use of disulfiram, we elected not to test this compound ^{21 (link)}.