Development of alcohol deprivation effect in rats: lack of correlation with saccharin drinking and locomotor activity

The present study addressed the relationship between the parameters of saccharin drinking behaviour and locomotor activity in an open field environment and long-term alcohol self-administration. In a 22-day initiation phase, male Wistar rats were presented with increasing concentrations of ethanol (2-8%, v/v) in a choice with water. The rats were then given the choice between water and two ethanol solutions (8 and 16%). Every 28 days, ethanol was withdrawn for 5 days. The ethanol intake and the transient increase in ethanol consumption after each of six deprivation episodes (alcohol deprivation effect) was monitored and correlated with parameters of the subsequent saccharin drinking and open field tests. The total ethanol intake (g/kg/24 h) as well as the consumption of 16% ethanol were stable over time. However, the magnitude of the alcohol deprivation effect increased with the repeated deprivation episodes. None of the parameters measured in the open field or the saccharin drinking tests correlated with either ethanol consumption or the alcohol deprivation effect. These results suggest that (1) repeated episodes of ethanol deprivation may increase the magnitude of the alcohol deprivation effect, (2) neither saccharin drinking nor locomotor activity correlates with long-term ethanol drinking behaviour in rats.