Residual effects of chronic cannabis treatment on behavior in mature rats.
Mature rats (starting weight at least 270 g) were treated daily with cannabis extract (daily THC dose 20 mg/kg) for 3 months. After a 1- to 4-month drug-free period, residual effects on a variety of behaviors were studied. No residual effects were found in learning of an eight-arm radial maze task, nor on a differential reinforcement of low-rate responding (DRL-20) task, nor on open field activity. On the other hand, two-way shuttle box avoidance learning was facilitated by previous cannabis treatment, since cannabis-treated rats exhibited shorter mean latencies to avoid footshock than vehicle controls. The findings indicate greater vulnerability of immature organisms (previous studies) than mature organisms (the present study) to long-term effects of chronic cannabis administration.
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects*; D002188:Cannabis; D003216:Conditioning, Operant / Q000187:drug effects; D007858:Learning / Q000187:drug effects; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000187:drug effects; D012055:Reinforcement Schedule
D010936:Plant Extracts