Orphanin FQ/nociceptin blocks acquisition of morphine place preference

Brain Res. 1999 Jun 19;832(1-2):168-70. doi: 10.1016/s0006-8993(99)01425-0.


Orphanin FQ/nociceptin (OFQ/N) suppresses the activity of the dopaminergic mesolimbic reward pathway yet reportedly fails to produce conditioned place aversion or preference. The present study sought to determine if this peptide could attenuate the development of morphine place preference. Male rats were administered OFQ/N (3 to 30 nmol intracerebroventricularly) during the induction of morphine (3 mg/kg subcutaneously) place preference. Animals receiving 3 or 10 nmol (but not 30 nmol) OFQ/N showed significant reductions in the development of place preference to morphine.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Analysis of Variance
  • Animals
  • Choice Behavior / drug effects*
  • Conditioning, Operant / drug effects*
  • Cues*
  • Injections, Intraventricular
  • Male
  • Morphine / antagonists & inhibitors*
  • Opioid Peptides / pharmacology*
  • Rats
  • Rats, Sprague-Dawley


  • Opioid Peptides
  • Morphine
  • nociceptin