Abstract: Novelty seeking or sensation seeking is often associated with susceptibility to substance abuse. In preclinical studies, high and low novelty seeking animals show different sensitivities to locomotor stimulating, rewarding and reinforcing effects of drugs of abuse, such as cocaine, amphetamine and morphine. It is well known that chronic alcohol consumption can result in alcoholism; however, little is known about the relationship between novelty seeking behavioral trait and propensity to alcoholism. The present study examined the relationship between novelty seeking and the response to acute or repeated ethanol treatment using locomotor activity as the behavioral endpoint. Adult male KM mice were categorized as HR (high responders in novel environment) and LR (low responders in novel environment), or HOP (high object preference) and LOP (low object preference) based on their activities in a novel environment and novel object preference. After baseline activity measurements, subjects were tested daily after i.p. injections of either ethanol (2g/kg/d) or saline for 10 days. Two days later, ethanol (2g/kg) was re-tested in all animals. LR mice were more sensitive than HR mice to acute and chronic ethanol induced hyperactivity. When challenged with ethanol 2 days after repeated ethanol treatment, the locomotor stimulating effect of ethanol was more robust in LR mice than in HR mice. No such difference was observed in HOP mice and LOP mice. In conclusion, locomotor activity in a novel environment may predict the locomotor stimulating effects of ethanol in KM mice.

Key words: novelty seeking, sensation seeking, ethanol or alcohol, locomotor activity