Orphanin FQ/nociceptin: a role in pain and analgesia, but so much more

Trends Neurosci. 1998 May;21(5):215-21. doi: 10.1016/s0166-2236(97)01204-6.


The publication of the delta opioid receptor sequence led to the cloning of three homologous receptors: the mu and kappa opioid receptors, and a novel opioid-like orphan receptor. The orphan receptor's endogenous ligand, a 17-amino-acid peptide that resembles dynorphin, was named 'orphanin FQ' and 'nociceptin' (OFQ/N1-17). The OFQ/N1-17 receptor is expressed widely in the nervous system, and it is becoming clear that the peptide is likely to participate in a broad range of physiological and behavioral functions. At the cellular level, OFQ/N1-17 has much in common with the classical opioids; however, functional studies are now revealing distinct actions of this peptide. Identified only two years ago, OFQ/N1-17 has already attracted a great deal of attention. The number and diversity of papers focused on OFQ/N1-17 at the recent meeting of the Society for Neuroscience augur an exciting future for this new peptide.

Publication types

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

MeSH terms

  • Analgesia*
  • Animals
  • Brain / physiology
  • Humans
  • Narcotic Antagonists
  • Nociceptin
  • Nociceptin Receptor
  • Opioid Peptides / physiology*
  • Pain / physiopathology*
  • Receptors, Opioid / agonists
  • Receptors, Opioid / metabolism
  • Spinal Cord / physiology


  • Narcotic Antagonists
  • Opioid Peptides
  • Receptors, Opioid
  • Nociceptin Receptor
  • OPRL1 protein, human