Effects of the cannabinoid receptor agonist WIN 55,212-2 on operant behavior and locomotor activity in rats.
Cannabinoids influence the motivational state of a subject and affect motor behavior. In the present study, we examined the acute effects of the cannabinoid (CB) receptor agonist WIN 55,212-2 (WIN) in three different doses (0.6, 1.2 and 1.8 mg/kg) on the performance of rats in a progressive ratio operant behavior task and on locomotor activity. WIN dose-dependently reduced the break point and the total number of lever-presses under a progressive ratio schedule. A food preference test revealed a preference for freely available casein pellets over lab chow in all treatment groups, indicating no WIN-effects on primary motivation. There was a significant reduction in the amount of casein pellets consumed by animals treated with 1.8 mg/kg WIN. Locomotor activity in the open field was increased by 0.6 mg/kg, but not by higher doses of WIN. These data show that administration of the synthetic cannabinoid receptor agonist WIN leads to dose-dependent alterations of the performance in an operant behavior task and of motor behavior. We confirm previous findings of dose-dependent motor stimulating and inhibiting effects of cannabinoids, and show an impairment of a complex operant behavior at higher doses of WIN.
Drews
Eva
E
Brain Research Institute, Department of Neuropharmacology, University of Bremen, P.O. Box 33 04 40, 28334 Bremen, Germany.
Schneider
Miriam
M
Koch
Michael
M
D000818:Animals; D048588:Benzoxazines; D063386:Cannabinoid Receptor Agonists; D002186:Cannabinoids / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D008297:Male; D009025:Morpholines / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D009281:Naphthalenes / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D043882:Receptors, Cannabinoid / Q000502:physiology
D048588:Benzoxazines; D063386:Cannabinoid Receptor Agonists; D002186:Cannabinoids; D009025:Morpholines; D009281:Naphthalenes; D043882:Receptors, Cannabinoid; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone