Effects of buspirone differ from those of gepirone and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) on unpunished responding of pigeons.

Under several behavioral procedures, such as punished responding and drug discrimination, the effects of the atypical anxiolytic buspirone are similar to those of its analogue gepirone, and to those of the 5-HT1A receptor agonist 8-OH-DPAT. Similarities in the effects of these compounds occur despite the fact that buspirone produces strong dopaminergic actions, whereas both gepirone and 8-OH-DPAT effects mainly appear to be serotonergically mediated. When keypeck responding of pigeons was maintained under a multiple 3-min fixed-interval, 30-response fixed ratio schedule of food presentation, responding under both the fixed-interval and fixed-ratio schedules was decreased over a range of buspirone doses (0.3-5.6 mg/kg). As has been reported with many antipsychotic compounds, performance under the fixed-interval schedule was more sensitive to the rate-decreasing effects of buspirone. In contrast, both gepirone (0.03-3.0 mg/kg) and 8-OH-DPAT (0.03-1.0 mg/kg) increased responding under the two schedules. Differences in the effects of buspirone from the other compounds in this study, compared to the similar effects of these drugs obtained using other procedures, emphasize the importance of the specific behavior as a determinant of drug action. The multiple fixed-interval, fixed-ratio schedule may be useful for delineating the relative balance of dopaminergic and serotonergic effects produced by drugs that are less apparent using other behavioral procedures.(ABSTRACT TRUNCATED AT 250 WORDS)