Cannabinoid receptors and reward in the rat : a conditioned place preference study

• Published in: Psychopharmacologia Vol. 151; no. 1; pp. 25 - 30
• Main Authors: CHEER, J. F, KENDALL, D. A, MARSDEN, C. A
• Format: Journal Article
• Language: English
• Published: Berlin Springer 21.07.2000
• Subjects: Animals; Avoidance Learning - drug effects; Biological and medical sciences; Cannabinoids - antagonists & inhibitors; Cannabinoids - pharmacology; Conditioning (Psychology) - drug effects; Dronabinol - analogs & derivatives; Dronabinol - pharmacology; Drug addictions; Male; Medical sciences; Piperidines - pharmacology; Pyrazoles - pharmacology; Rats; Receptors, Cannabinoid; Receptors, Drug - drug effects; Receptors, Drug - metabolism; Reward; Rimonabant; Substance Withdrawal Syndrome; Toxicology; Nervous system diseases; Agonist; Intraperitoneal administration; Conditioned place preference; Rat; Toxicity; Rodentia; Detoxification; Instrumental conditioning; Cannabinoid; Dose activity relation; Learning; Vertebrata; Mammalia; Acquisition process; Animal; Reinforcement; Drug of abuse; Antagonist; Reward; Withdrawal syndrome; Avoidance; Biological receptor
• ISSN: 0033-3158; 1432-2072
• DOI: 10.1007/s002130000481

We wished to investigate further the hypothesis of an endogenous cannabinoid 'aversive counter-rewarding system, as the rewarding properties of cannabinoids using standard procedures remain ambiguous. The purpose of this study was to confirm the behavioural effects of a highly potent synthetic cannabinoid agonist (HU210) and the selective cannabinoid antagonist SR 141716A using conditioned place preference (CPP). HU210 (20, 60 and 100 microg kg(-1), SR141716A (0.25, 0.5, 2 and 3 mg kg(-1)), cocaine (15 mg kg(-1) and delta9-THC (1.5 mg kg(-1)) were given to male Lister hooded rats using an unbiased CPP design. SR141716A and cocaine produced place preference at all doses tested, whereas HU210 and delta9-THC produced aversion as expressed by time spent in the drug-paired compartment of the CPP apparatus. The aversive effects of cannabinoid agonists and the rewarding effect of the cannabinoid antagonist are suggestive of a cannabinergic tone in the rat brain. Further research is needed to determine the precise relationship of that tone with the reward pathways of the brain.