Discriminative stimulus properties of buspirone compared to central nervous system depressants in rats

Two groups of rats were trained to discriminate either IP buspirone from vehicle or IP oxazepam from vehicle using a two-lever FR-10 schedule of sweetened milk presentation. The discrimination in the buspirone group was difficult to establish due to potent response rate decreasing effects. Oxazepam was a very effective stimulus and the discrimination in the oxazepam group was readily established. Tests with oxazepam and pentobarbital in the buspirone group provided no evidence for generalization of the stimulus properties of buspirone to either drug. Tests with buspirone in the oxazepam group also provided no evidence of generalization to buspirone, although tests with pentobarbital indicated almost complete generalization. Finally buspirone and oxazepam were tested in a group of rats previously trained to discriminate pentobarbital from vehicle. The findings supported the data obtained in the buspirone and oxazepam groups, with no indication of generalization from pentobarbital to buspirone, but with complete generalization to oxazepam. These data suggest that buspirone does not share discriminative stimulus properties which are common to other CNS depressants.