title: [Morphine self-administration added to food conditioning: methodological variant in rats].
abstract: Rats with permanent intra-jugular cannula are submitted to an alimentary operant reinforcement schedule with fixed ratio type FR 1, FR5, then FR 20. As a result, the animals are self administering (together with the alimentary inducer) a slow (about 5 sec) intravenous infusion of morphine (0.05 mg/kg). 20 per cent only of the experimental population exhibit a psychogenic dependance afterward. On the other hand, the animals for which morphine self-administration has been substituted to the alimentary reinforcement without respecting a transitory period combining both types of reinforcement have never shown any tendancy toward morphine self-administration. The lack of positive results could be related to the marked duration of the self-injection.
mesh_terms: D000818:Animals; D003216:Conditioning, Operant; D004195:Disease Models, Animal; D005502:Food; D006801:Humans; D008297:Male; D009020:Morphine / Q000008:administration & dosage*; D051381:Rats; D012054:Reinforcement, Psychology; D012646:Self Administration; D019966:Substance-Related Disorders
chemical_list: D009020:Morphine
vernacular_title: Auto-injections morphiniques substituées au conditionnement alimentaire: étude chez le rat d'une variante méthodologique.