Effects of the environment on the behavioural response of mice to non-ataxic doses of ethyl alcohol.

An ethological analysis was used to examine the effects of ethyl alcohol on social behaviour in mice which were placed in different social contexts. In encounters between unfamiliar males, alcohol-treated mice from a diverse environment showed more exploration on the bars of an unfamiliar cage and less social investigation than controls. In an encounter situation between males and females, male mice given alcohol showed a significant increase in frequency and duration of all forms of social and sexual investigation other than mounts and attempted mounts compared with untreated males. In a territorial situation, alcohol administration before territory establishment resulted, on each of four occasions, in the dominant mouse of the alcohol-treated group becoming despot over the whole enclosure, whereas after territory establishment this effect was not seen. The overall effect of alcohol was, therefore, to increase the type of behaviour that was already stimulated by the test situation. The significance of these findings in relation to the differential effects of alcohol on different areas of the nervous system is discussed.