Phencyclidine-like discriminative stimulus properties of opioids in the squirrel monkey

摘要: The opioids SKF 10047, dl-cyclazocine, and dextrorphan have been shown to phencyclidine (PCP)-like discriminative stimulus properties in the rat. In order extend generality of this observation, effects these other were evaluated squirrel monkeys trained discriminate between IM injections saline 0.25 mg/kg PCP a two-choice discrete-trial avoidance paradigm. Stimulus control behavior was characterized by reliable completion at least 22 trials 25-trial session on appropriate choice lever after an injection or PCP. tests generalization, d-cyclazocine, dextrorphan, normetazocine, l-cyclazocine, dextromethorphan occasioned dose-related increases PCP-appropriate responding. first four compounds and, under some conditions, l- produced comparable that training dose. Six responding only saline-appropriate lever: ethylketocyclazocine, ketocyclazocine, levorphanol, levallorphan, pentazocine, naltrexone. Naltrexone (1.0 4.0 mg/kg) attenuated slightly PCP-like 10047 but increased with dl-cyclazocine levorphanol enabling higher doses drugs be tested without disruption certain appear mediated neuronal substrates acted upon rather than sites typically associated opiate activity. These action common may correspond sigma “opiate” receptor.