Acute nicotine and phencyclidine increase locomotor activity of the guinea pig

Abstract

While the behavioral effects of nicotine and phencyclidine have been well characterized in rats and mice, substantially less is known about their effects in guinea pigs. Understanding the pharmacology of these compounds has relevance to both addictive behaviors and psychoses. In some circumstances, human pharmacology may be better represented by guinea pigs than by rats or mice. The goal of this study was to determine the utility of the guinea pig as a model for assessing the behavioral actions of nicotine and phencyclidine, drugs that have locomotor stimulant activity in rat and mouse.Nicotine (1‐3 mg/kg) dose‐dependently increased locomotor activity. The time courses of the responses were also dose‐dependent. Phencyclidine (3‐10 mg/kg) increased locomotor activity with effects that were longer‐lasting than those of nicotine.Both the magnitude and duration of the increased locomotor activity are less than that seen with mouse or rat models under otherwise similar conditions. Additionally, higher doses of nicotine and phencyclidine are required to produce locomotor stimulation in the guinea pig. These data suggest that, in terms of responsiveness to psychomotor stimulants, the guinea pig is a less sensitive model species than rats or mice.