title: Restricted feeding does not modify discriminative stimulus effects of morphine in the rat.
abstract: An experiment was performed to determine if the discriminative stimulus effects of morphine are modified by mild food deprivation, a condition that increases drug-reinforced behavior. Rats were trained to discriminate between SC injections of saline and morphine (3.0 mg/kg) in a discrete-trial shock-avoidance procedure. Stimulus generalization curves for morphine were then determined on three occasions by a cumulative-dosing procedure: before, during and after the body weight of the rats had been reduced to 86-87% of normal by restricted feeding. Food deprivation had little or no effect on the morphine generalization curve. Despite a close relationship between the reinforcing and discriminative stimulus properties of opioid drugs, stimulus control of behavior by morphine was not modified by a condition that enhances opioid-reinforced behavior.
authors.affiliation: Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322.
authors.forename: M
authors.initials: M
authors.lastname: Ukai
authors.forename: S G
authors.initials: SG
authors.lastname: Holtzman
mesh_terms: D000818:Animals; D004032:Diet; D004193:Discrimination Learning / Q000187:drug effects; D004192:Discrimination, Psychological / Q000187:drug effects*; D005795:Generalization, Stimulus / Q000187:drug effects; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D051381:Rats
chemical_list: D009020:Morphine