Behavioral effects of intraventricularly administered (-)-nicotine on fixed ratio schedules of food presentation in rats.
The behavioral effects of intraventricularly (IVT) administered (-)-nicotine on food-maintained behavior were studied. Rats responded by pressing a lever under various fixed ratio (FR) schedules. Infusion of 5 microgram of (-)-nicotine suppressed responding under an FR 16 schedule for 11-13 min. The effect was inversely related to the ratio size (16, 32, 64 responses per food delivery), but it was directly related to the infused (-)-nicotine dose (0.312, 0.624, 1.25, 2.5, 5.0, 10.0 microgram) when ratio size was held constant. Responses rates following the (-)-nicotine-induced suppression were similar to those obtained prior to infusion. The behavioral effects of (-)-nicotine were blocked, in a dose-related manner, by the centrally acting nicotinic-cholinergic antagonist, mecamylamine (0.05-3.0 mg/kg) but not by ther peripherally acting antagonist, hexamethonium (0.5-3.0 mg/kg), suggesting that the behavioral effects of IVT infusions of (-)-nicotine are mediated by central nicotine-cholinergic receptors.
D000818:Animals; D001921:Brain / Q000187:drug effects; D003216:Conditioning, Operant / Q000187:drug effects*; D005502:Food; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008297:Male; D008464:Mecamylamine / Q000494:pharmacology; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000187:drug effects
D006584:Hexamethonium Compounds; D008464:Mecamylamine; D009538:Nicotine