Morphine-conditioned changes in locomotor activity

Role of the conditioned stimulus

Rick A Bevins, Michael T. Bardo

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

When a multisensory environment was reliably paired with morphine (2 mg/kg) in rats, that environment, in a drug-free test, evoked a hyperactive conditioned response (CR). When an olfactory cue (banana odor) was the only stimulus element reliably paired with morphine, it also elicited a hyperactive CR. However, a gustatory cue (saccharin solution) evoked a hypoactive CR. This taste-elicited decrease in activity was dose dependent; morphine at 2 and 4 mg/kg conditioned hypoactivity, whereas a higher dose (8 mg/kg) did not. A robust conditioned saccharin aversion occurred only at the highest dose of morphine, suggesting disassociation between the hypoactive CR and taste aversion. A taste cue present during context conditioning also prevented either acquisition or expression of the hyperactive CR to the context. The modality of the conditioned stimulus is a critical determinant of the form of the CR in a morphine locomotor conditioning paradigm.

Original languageEnglish (US)
Pages (from-to)131-138
Number of pages8
JournalExperimental and Clinical Psychopharmacology
Volume6
Issue number2
DOIs
StatePublished - Jun 13 1998

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Locomotion
Morphine
Cues
Saccharin
Musa
Pharmaceutical Preparations
Conditioning (Psychology)

ASJC Scopus subject areas

  • Pharmacology
  • Psychiatry and Mental health
  • Pharmacology (medical)

Cite this

Morphine-conditioned changes in locomotor activity : Role of the conditioned stimulus. / Bevins, Rick A; Bardo, Michael T.

In: Experimental and Clinical Psychopharmacology, Vol. 6, No. 2, 13.06.1998, p. 131-138.

Research output: Contribution to journalArticle

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