Abecarnil and palatability: Taste reactivity in normal ingestion in male rats

Effects of the anxioselective anxiolytic abecarnil, a β-carboline benzodiazepine-receptor agonist, on initial licking responses for a 3% sucrose solution and on taste reactivity responses were evaluated in adult male rats. The rats' behaviour was video recorded, and analysed according to a frame-by-frame procedure to generate the durations of categorized fixed action patterns, and the number and rate of licking responses. The results indicated that abecarnil (0.3-3.0 mg/kg, i.p.) significantly increased the number of licks in the first continuous sample of licking, while significantly reducing the lick rate (licks/s). Additionally, abecarnil selectively enhanced positive ingestive responses, but had no effect on either neutral or aversive response categories in taste reactivity measures. On the basis on this pattern of results, we conclude that abecarnil can enhance taste palatability selectively, and that it may act as an agonist at GABAA benzodiazepine receptor subtypes which mediate drug effects on ingestive behaviour.