Anxiolytic profiles of alprazolam and ethanol in the elevated plus-maze test and the early acquisition of shuttlebox avoidance.

Rats pretreated either with the anxiolytic triazolobenzodiazepine alprazolam (0.75 and 1.75 mg kg-1 i.p.) or ethanol (1, 2, 3 and 4 g kg-1 p.o.) were tested in both the elevated plus-maze and the early acquisition of shuttlebox avoidance. Both substances induced overall anxiolytic effects in the plus-maze, with the 0.75 mg kg-1 being the most effective alprazolam dose and 1-3 g kg-1 being the most effective ethanol doses. Both drugs were also anxiolytic in the shuttlebox, since 1.75 mg kg-1 alprazolam and 2-3 g kg-1 ethanol improved acquisition of the task. Correlational and factor analysis showed that behaviour in the open arms of the plus-maze and efficiency in shuttlebox avoidance acquisition are positively associated, thus providing further support to the contention that the early acquisition of shuttlebox avoidance is an animal model of anxiety.