The effects of Ro 15-1788 on anxiolytic self-administration in the rhesus monkey

The ability of a benzodiazepine antagonist, Ro 15-1788, to modify the self-administration of anxiolytics was determined in rhesus monkeys. Lever-press responding was maintained in four monkeys under a fixed-ratio 10 schedule of drug delivery in daily sessions of 2 hr duration. Responding was maintained either by flurazepam, lorazepam or pentobarbital. When responding was stable for each of these drugs, a range of doses of a benzodiazepine antagonist, Ro 15-1788 (0.0001-10 mg/kg, IM), was given 5 min prior to a session. At some doses the antagonist increased responding for lorazepam and flurazepam whereas pentobarbital self-administration was largely unaffected or reduced. These results suggest that Ro 15-1788 was able to specifically modify the effects of benzodiazepines responsible for drug-maintained performance.