Effect of drugs on catnip (Nepeta cataria)-induced pleasure behavior in cats.

Cats exposed to stuffed toys sprayed with catnip (Nepeta cataria) ex­ tract exhibited pleasurable behavior which was divisible into 6 phases and which terminated in approximately 10 minutes. Preadministered drugs which shortened the response included atropine sulfate, physostigmine, neostigmine, pilocarpine, mecamylamine, methysergide, and pentobarbital. Hexamethonium, amphetamine, 5-hydroxytryptophan, atropine plus methy­ sergide, and diphenylhydantoin abolished the response. The effect of diphenylhydantoin took several weeks to disappear. Response was prolonged by morphine, chlorpromazine, and histidine. Atropine methyl nitrate, V-(2-chloroethyl)dibenzylamine, propranolol, and chlorpheniramine did not affect duration of response. Most drugs and several environmental, physio­ logic, and psychologic factors altered the response qualitatively. The results indicated peripheral nicotinic and central muscarinic cholinoceptive and serotonergic facilitation of the catnip response, with a prominent voluntary component. Inhibition of response seemingly involved central muscarinic and nicotinic cholinoceptive mechanisms linked with an adrenoceptive com­ ponent. Interrelationships proposed for these components support current concepts of behavior control. The catnip response may be suited to the study of pleasure behavior and olfaction and may be used as a model of human reactions to marijuana and lysergic acid diethylamide (lsd).