BEHAVIORAL EFFECTS OF A CHOLINERGIC STIMULANT IN COMBINATION WITH VARIOUS PSYCHOTHERAPEUTIC AGENTS

¹ Mellon Institute, Pittsburgh, Pennsylvania

The psychopharmacological effects of the anticholinesterase agent, 1-naphthyl N-methyl carbamate (carbaryl) have been studied in rats trained in a discrete avoidance behavioral situation or a variable ratio food-reward program. A dose of 5.0 mg/kg of carbaryl was necessary to cause a significant increase in the percent of shocks taken in 80% of the animals for the first 30 minutes following intraperitoneal injection. A dose of 7.0 mg/kg significantly reduced normal food consumption in 80% of food-reward animals. These doses were studied in combination with representative psychotherapeutic agents.

Similar results were obtained with both negatively and positively motivated behavior. combination of pentobarbital or chlordiazepoxide with carbaryl yielded purely additive effects on behavior. Less than additive behavioral changes were obtained when carbaryl was given with imipramine, while a considerably greater than additive effect was obtained in studies with chiorpromazine. Combination of pilocarpine with chlorpromazine also revealed significant potentiation of altered behavior. No augmentation of brain cholinesterase inhibition was observed when chlorpromazine was combined with the anticholinesterase agent. Possible imbalance in the trophotropic-ergotropic system is offered in attempts to explain interaction results with these agents.