PHARMACOLOGICAL EVALUATION OF ALCOHOL WITHDRAWAL-INDUCED INHIBITION OF EXPLORATORY-BEHAVIOR AND SUPERSENSITIVITY TO HARMINE-INDUCED TREMOR

Rats given a liquid diet containing 10% (v/v) alcohol consume high qua ntities of alcohol. Within 8 hr after cessation of the alcohol intake, the animals will show alcohol-withdrawal reactions including a supers ensitivity to harmine-induced tremor and an inhibition of exploratory behaviour in a neutral environment. Several drugs can overcome one or more of these alcohol withdrawal reactions. A reduction of the alcohol withdrawal-induced inhibition of exploration, in terms of both the nu mber of transits into the open field and the time spent in the open fi eld, was obtained with chlordiazepoxide, ritanserin, n-mianserin and p ropranolol. Of these four compounds, propranolol and n-mianserin were also active against the supersensitivity to both 5.00 and 10.00 mg/kg harmine-induced tremor. Chlordiazepoxide and ritanserin were only acti ve against 5.00 mg/kg harmine. Other compounds that reversed the super sensitivity to harmine-induced tremor during alcohol withdrawal includ ed buspirone, fluoxetine, haloperidol, clonidine, flunarizine and bacl ofen. Very limited effects on both alcohol withdrawal reactions were o bserved with ondansetron, nimodipine and MK-801. Risperidone and SCH 2 3390 were inactive. These results demonstrate that some alcohol withdr awal reactions can be studied in a systematic way and that various pha rmacological agents can differentially interact with these alcohol wit hdrawal reactions.