The effects of delta 9-tetrahydrocannabinol alone and in combination with cannabidiol on fixed-interval performance in rhesus monkeys.
It has been reported that cannabidiol (CBD) antagonizes the effects of delta 9-tetrahydrocannabinol (THC) on operant behavior in rats and pigeons. We have replicated this finding with rhesus monkeys. Four rhesus monkeys were trained to lever press on a fixed-interval 5-min schedule of food presentation with a 1-min limited hold and 1-min time out between successive intervals. The effects of 0.3 and 1.0 mg/kg THC alone were determined three times during the experiment; before the CBD-THC interaction, after the CBD-THC interaction and once with the CBD vehicle. A dose of 30 mg/kg CBD, which alone resulted in a 24% reduction in responding, completely antagonized the response rate reduction produced by 0.3 mg/kg THC. The effects of THC revealed a rate-dependent effect that did not conform to the log-linear rate-dependency plots described for most other drugs.
D000818:Animals; D002185:Cannabidiol / Q000008:administration & dosage / Q000494:pharmacology*; D002186:Cannabinoids / Q000494:pharmacology*; D003216:Conditioning, Operant / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008253:Macaca mulatta; D008297:Male; D012055:Reinforcement Schedule
D002186:Cannabinoids; D002185:Cannabidiol; D013759:Dronabinol