PMID: 6122153Jan 25, 1982

Discriminative stimulus, antagonist, and rate-decreasing effects of cyclorphan: multiple modes of action

Life Sciences
S HerlingJ H Woods


This discriminative effects of cyclorphan were studied in pigeons trained to discriminate 0.32 mg/kg ethylketazocine, 1.8 mg/kg cyclazocine, or 32 mg/kg naltrexone from saline. A fourth group of pigeons was administered 100 mg/kg/day morphine and trained to discriminate 0.1 mg/kg naltrexone from saline. Cyclorphan produced dose-related ethylketazocine-appropriate responding that reached a maximum of 83% of the total session responses at 0.3 mg/kg. Higher cyclorphan doses produced less ethylketazocine-appropriate responding. IN pigeons trained to discriminate cyclazocine from saline, maximum drug-appropriate responding of greater than 90% occurred at 5.6-10.0 mg/kg cyclorphan. In narcotic-naive pigeons trained to discriminate 32 mg/kg naltrexone from saline, cyclorphan produced a maximum of less than 50% drug-appropriate responding. In contrast, in pigeons chronically administered morphine and trained to discriminate 0.1 mg/kg naltrexone from saline, 1.0 mg/kg cyclorphan resulted in 100% drug-appropriate responding. In pigeons responding under a multiple fixed-interval, fixed-ratio schedule of food delivery, cyclorphan produced a complete dose-related reversal of the rate-decreasing effects of 10 mg/kg morphine, the maximally ef...Continue Reading


Sep 1, 1979·Proceedings of the National Academy of Sciences of the United States of America·J P VincentM Lazdunski
Oct 1, 1979·Proceedings of the National Academy of Sciences of the United States of America·S R Zukin, R S Zukin
Nov 15, 1977·Psychopharmacology·I D Hirschhorn
Jan 1, 1981·Psychopharmacology·S Herling, J H Woods


Jan 1, 1992·Psychopharmacology·A J Bertalmio, J H Woods

Related Concepts

Conditioning (Psychology)
Discrimination Learning
Dose-Response Relationship, Drug
Morphine Sulfate (2: 1), Pentahydrate
Columba livia
Ethylketocyclazocine Methanesulfonate

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