This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Gauvin, D. V. Articles by Holloway, F. A. Search for Related Content PubMed Articles by Gauvin, D. V. Articles by Holloway, F. A. Social Bookmarking                         What's this?

The discriminative stimulus properties of an ethanol-nicotine mixture in rats

Psychobiology Laboratories, Department of Psychiatry and Behavioral Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73190-3000 USA

Frank A. Holloway

Psychobiology Laboratories, Department of Psychiatry and Behavioral Sciences, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73190-3000 USA

Sprague-Dawley rats were trained to discriminate between saline (SAL) and an ethanol-nicotine mixture (0.5 g/kg ethanol plus 0.5 mg/kg nicotine) administered 15 min prior to a 15-min drug discrimination training session under a FR-10 schedule of reinforcement. The mixture dose ratio was adjusted after training to obtain a drug mixture with which both individual drugs contributed about equally to the stimulus control (1.0 g/kg ethanol plus 0.3 mg/kg nicotine). The animals were then retrained for 32 sessions using this new mixture. After training, neither nicotine nor ethanol, when tested singly, engendered > 90% mixture-appropriate responding up to test doses that suppressed responding. Complete generalization occurred when the training doses of either nicotine or ethanol were administered in combination with various doses of the alternate drug element. (+)Nicotine, amphetamine and caffeine engendered dose-dependent increases in responses emitted on the mixture-appropriate lever. Pentobarbital and chloral hydrate only partially generalized to the training mixture. However, depressant/stimulant combinations of chloral hydrate+caffeine and pentobarbital+amphetamine produced complete generalization. The data suggest: (1) drug mixtures are not normally perceived as new entities distinct from their component elements; (2) training dose ratio may influence the characteristics of mixture discriminations; (3) stimulus element saliency may be a factor determining the nature of discriminative control by drug mixture cues; and (4) the ethanol-nicotine cue was most likely based on non-specific depressant/stimulant effects of these drugs.

Key Words: drug discrimination • ethanol • nicotine • drug mixtures • stimulus equivalency

Journal of Psychopharmacology, Vol. 7, No. 1 suppl, 52-62 (1993)
DOI: 10.1177/026988119300700109


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?