Comparison of phencyclidine, etoxadrol and dexoxadrol in the pigeon

The effects of phencyclidine, etoxadrol and dexoxadrol were compared in pigeons responding under a multiple fixed-ratio 30-response, fixed-interval 5-minute schedule of grain presentation. Etoxadrol was half as potent as phencyclidine in suppressing responding, and dexoxadrol was half as potent as etoxadrol. These three drugs, along with ketamine and cyclazocine, were also compared in pigeons trained to discriminate injections of 0.64 mg/kg of phencyclidine from injections of distilled water. All five drugs produced phencyclidine-like responding at the higher doses, with the order of potency being phencyclidine, etoxadrol, cyclazocine, dexoxadrol and ketamine. These data showed that a phencyclidine-like discriminative cue can be demonstrated across three classes of chemical compounds, as exemplified by phencyclidine and ketamine, etoxadrol and dexoxadrol, and cyclazocine.