Delta9-tetrahydrocannabinol, but not the endogenous cannabinoid receptor ligand anandamide, produces conditioned place avoidance.
Although exogenous cannabinoid ligands such as delta9-tetrahydrocannabinol (THC) have been implicated in reward-related learning and aversion, the hedonic effects of the endogenous cannabinoid agonist anandamide (arachidonylethanolamide) have never been assessed. Thus, the effects of anandamide were tested in a place conditioning task. Male Wistar rats received THC (0.0-8.0 mg/kg) or anandamide (0.0-16.0 mg/kg) during conditioning sessions. The half-life of anandamide was increased by pretreatment with the protease inhibitor phenylmethylsulfonyl fluoride (2.0 mg/kg). A significant place aversion was found at the 1.0 and 1.5 mg/kg doses of THC. No significant place conditioning effects were found with anandamide. Locomotor activity during conditioning was significantly decreased by the 1.0, 1.5, 2.0 and 4.0 mg/kg doses of THC as well as the 8.0 and 16.0 mg/kg doses of anandamide. These results fail to implicate the endogenous cannabinoid anandamide in reward-related learning or aversion.
Mallet
P E
PE
Department of Psychology, Queen's University, Kingston, Ontario, Canada.
Beninger
R J
RJ
D000818:Animals; D001095:Arachidonic Acids / Q000493:pharmacokinetics / Q000494:pharmacology*; D001362:Avoidance Learning / Q000187:drug effects*; D002186:Cannabinoids / Q000493:pharmacokinetics / Q000494:pharmacology*; D013759:Dronabinol / Q000493:pharmacokinetics / Q000494:pharmacology*; D063388:Endocannabinoids; D006207:Half-Life; D006213:Hallucinogens / Q000493:pharmacokinetics / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D053284:Polyunsaturated Alkamides; D011480:Protease Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug / Q000187:drug effects*
D001095:Arachidonic Acids; D002186:Cannabinoids; D063388:Endocannabinoids; D006213:Hallucinogens; D053284:Polyunsaturated Alkamides; D011480:Protease Inhibitors; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug; D010664:Phenylmethylsulfonyl Fluoride; D013759:Dronabinol; C078814:anandamide