REPEATED CHARACTERIZATION OF ALCOHOL-WITHDRAWAL REACTIONS IN RATS CHRONICALLY EXPOSED TO AN ALCOHOL LIQUID DIET

1. Rats given a 10-% (v/v) alcohol liquid diet over long periods of ti me reach high blood alcohol levels of more than 200 mg/dl over several weeks. 2. Repeated discontinuation of the alcohol intake resulted, ea ch time within 8 hr, in several withdrawal reactions including a reduc tion in exploratory behaviour and tremorogenic activity. 3. The inhibi tion of exploratory activity was measured in a neutral two-chamber mod el, both in terms of the number of transits into the open area as well as the time spent in the open space. The differences in exploration r emained over the 4 successive withdrawal tests. 4. Rats in alcohol wit hdrawal were also consistently less active than control animals in the tremor cages equipped with a piezofilm floor, and this despite the pr esence of a clearly visible tremor in the hindpaws when lifted up. 5. Alcohol withdrawal rats revealed a more frequent tremor activity than controls after a challenge with 5 mg/kg harmine. This effect was indep endent of the length of the tremor bursts used to quantify harmine-ind uced tremor starting from the second withdrawal period onwards. 6. Wit h a dose of 10 mg/kg harmine, ceiling effects were reached in both the alcohol withdrawal and control rats and differences between the two g roups were only present during the first exposures. 7. Overall, these results indicate that it is possible to quantify some withdrawal react ions at repeated time intervals of alcohol cessation in rats chronical ly exposed to a 10-% alcohol liquid diet. As a consequence, these with drawal reactions can be studied in a more systematic way.