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Morphine conditioned reward is inhibited by MPEP, the mGluR5 antagonist

P Popik1, M Wróbel

  • 1Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343, Kraków, Poland. nfpopik@cyf-kr.edu.pl

Neuropharmacology
|January 16, 2003
PubMed

Insights

MPEP, a metabotropic glutamate receptor 5 antagonist, reduced conditioned morphine reward in mice. This compound did not impact learning or memory, suggesting a specific role for mGluR5 in morphine reward.

Area of Science:

  • Neuroscience
  • Pharmacology
  • Addiction Research

Background:

  • Opioid addiction is a major public health concern.
  • Metabotropic glutamate receptors (mGluRs) are implicated in reward pathways.
  • Understanding the role of specific mGluR subtypes in drug reward is crucial for developing targeted therapies.

Purpose of the Study:

  • To investigate the effect of MPEP, a selective mGluR5 antagonist, on conditioned morphine reward.
  • To assess the impact of MPEP on learning and memory processes.

Main Methods:

  • Conditioned place preference (CPP) paradigm in mice to assess morphine reward.
  • Elevated plus maze test to evaluate spatial learning and memory.
  • Administration of MPEP (10 and 30 mg/kg) and MK-801 (0.1 mg/kg) to mice.

Main Results:

  • Single morphine conditioning (10 mg/kg) induced place preference in mice.
  • MPEP (30 mg/kg) significantly inhibited the acquisition and expression of morphine-induced CPP.
  • MPEP did not affect locomotor activity, learning, or memory retrieval.

Conclusions:

  • mGluR5 antagonism with MPEP effectively reduces conditioned morphine reward.
  • mGluR5 plays a significant role in the acquisition and expression of morphine-associated memories.
  • MPEP shows potential as a therapeutic agent for opioid addiction treatment.

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