Cues predicting drug or food reward restore morphine-induced place conditioning in mice lacking delta opioid receptors.

ABSTRACT:

Rationale

The exact role of delta opioid receptors in drug-induced conditioned place preference (CPP) remains debated. Under classical experimental conditions, morphine-induced CPP is decreased in mice lacking delta opioid receptors (Oprd1 (-/-)). Morphine self-administration, however, is maintained, suggesting that drug-context association rather than drug reward is deficient in these animals.

Objectives

This study further examined the role of delta opioid receptors in mediating drug-cue associations, which are necessary for the expression of morphine-induced CPP.

Methods

We first identified experimental conditions under which Oprd1 (-/-) mice are able to express CPP to morphine (5, 10 or 20 mg/kg) in a drug-free state and observed that, in this paradigm, CPP was dep

SUBMITTER: Le Merrer J 

PROVIDER: S-EPMC5632531 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature