Withdrawal symptoms in a long-term model of voluntary alcohol drinking in Wistar rats

Long-term voluntary alcohol drinking with repeated alcohol deprivation episodes has been suggested as animal model for some aspects of alcoholism. Using a radiotelemetric system, the present study investigated the occurrence of withdrawal symptoms in long-term voluntarily alcohol drinking Wistar rats with (repeated alcohol deprivation group) and without (first alcohol deprivation group) prior alcohol deprivation experience. Six days after transmitter implantation, alcohol bottles were removed, and returned 4 days later. Alcohol deprivation induced hyperlocomotion in both groups. In the repeated alcohol deprivation group, hyperlocomotion was increased at the beginning of the alcohol deprivation phase and decreased during the following dark phase, suggesting that removal of the alcohol bottles might have become a conditioned withdrawal stimulus for this group. Both groups showed an enhanced alcohol intake after representation of alcohol bottles compared to preabstinence intakes (alcohol deprivation effect). However, alcohol intake of the repeated alcohol deprivation group was significantly increased compared to the first alcohol deprivation group at the end of the experiment. It is concluded that repeated alcohol deprivation experience might promote the development of alcohol addiction because of its latent stimulating effect on alcohol drinking that can be unveiled by (presumably mildly stressful) experimental situations.