Open AccessOrphanin FQ acts as an anxiolytic to attenuate behavioral responses to stress
Author(s) -
F. Jenck,
JeanLuc Moreau,
James R. Martin,
Gavin J. Kilpatrick,
Rainer K. Reinscheid,
Frederick J. Monsma,
HansPeter Nothacker,
Olivier Civelli
Publication year - 1997
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.94.26.14854
Subject(s) - nociceptin receptor , anxiolytic , anxiogenic , elevated plus maze , nop , neuropeptide , neuroscience , opioid peptide , pharmacology , receptor , opioid , anxiety , medicine , psychology , psychiatry
Orphanin FQ (OFQ, Nociceptin) is a recently discovered 17-amino acid neuropeptide that is structurally related to the opioid peptides but does not bind opioid receptors. OFQ has been proposed to act as an anti-opioid peptide, but its widespread sites of action in the brain suggest that it may have more general functions. Here we show that OFQ plays an important role in higher brain functions because it can act as an anxiolytic to attenuate the behavioral inhibition of animals acutely exposed to stressful/anxiogenic environmental conditions. OFQ anxiolytic-like effects were consistent across several behavioral paradigms generating different types of anxiety states in animals (light-dark preference, elevated plus-maze, exploratory behavior of an unfamiliar environment, pharmacological anxiogenesis, operant conflict) and were observed at low nonsedating doses (0.1–3 nmol, intracerebroventricular). Like conventional anxiolytics, OFQ interfered with regular sensorimotor function at high doses (>3 nmol). Our results show that an important role of OFQ is to act as an endogenous regulator of acute anxiety responses. OFQ, probably in concert with other major neuropeptides, exerts a modulatory role on the central integration of stressful stimuli and, thereby, may modulate anxiety states generated by acute stress.