Ethanol intake after chronic intoxication by inhalation of ethanol vapour in rats: behavioural dependence

In Wistar rats, which practically avoid ethanol when naive, it is possible to induce a large ethanol intake in a free-choice situation after chronic intoxication by ethanol vapour. In this study, we evaluated the ethanol intake of chronically intoxicated and control rats. The ethanol intake was increased in intoxicated animals but the intensity of the response varied according to individuals without any clear relation to the level of the intoxication. The results clearly showed in intoxicated animals two kinds of responders: alcohol-nonpreferring (27/95) and alcohol-preferring rats (68/95). In the alcohol-preferring rats, ethanol intoxication had induced an alcohol drinking-dependent behaviour; about 75% of the animals of this group drank more than 7 g/kg b.wt. per day and could be considered as behaviourally dependent on alcohol. Furthermore, this group presents most of the criteria of alcoholism that an animal model should ideally satisfy.