Suppression by the cannabinoid CB1 receptor antagonist, rimonabant, of the reinforcing and motivational properties of a chocolate-flavoured beverage in rats

• DOI: 10.1097/fbp.0b013e3282fe8888
• Publication Date: 2008-05-07T07:05:52Z
• Authors: Paola Maccioni; Daniela Pes; Mauro A.M. Carai; Gian Luigi Gessa; Giancarlo Colombo
• Keywords: Rimonabant

Pharmacological blockade of the cannabinoid CB1 receptor has been repeatedly reported to suppress intake food, including highly palatable foods, in laboratory animals. This study was designed investigate whether treatment with antagonist, rimonabant, would reduce reinforcing and motivational properties a chocolate-flavoured beverage [containing 5% (w/v) chocolate powder] nonfood-deprived nonwater-deprived Wistar rats trained self-administer this under an operant conditioning procedure. also aimed at assessing what degree self-administration behaviour could be manipulated environmentally. After period training maintenance behaviour, separate groups were exposed different experimental conditions [session length varying from 20 120 min; fixed ratio (FR) schedule reinforcement FR10 FR40; reinforcer presentation 2.5 10 s; concentration powder 0%]; other rat used test effect acute repeated rimonabant (1-5.6 mg/kg, intraperitoneally) on two schedules (FR10 progressive ratio) extinction responding. All rapidly acquired steadily maintained high levels beverage. Changes modified rats' behaviour; these changes seemed result attempt adjust their so as consume much possible when it presented its most concentration. Treatment dose-dependently suppressed When administered repeatedly, only modest tolerance developed reducing effect. Finally, resulted dose-dependent reduction beverage, measured by extinction-responding These results suggest that can reliably established is environmentally manipulable. crucial component neural substrate mediating food such