Tonic inhibition by orphanin FQ/nociceptin of noradrenaline neurotransmission in the amygdala

Eur J Pharmacol. 2004 Feb 6;485(1-3):197-200. doi: 10.1016/j.ejphar.2003.11.061.

Abstract

The present microdialysis study investigated whether nociceptin/orphanin FQ exerts a tonic inhibition of the release of noradrenaline in the basolateral nucleus of the amygdala in awake rats. The non-peptide competitive nociceptin/orphanin FQ (N/OFQ) peptide receptor antagonist J-113397 (20 mg/kg i.p.) induced an increase in the release of noradrenaline to about 150-200%. The increase was strongly suppressed by local infusion of an endogenous N/OFQ peptide receptor agonist, nociceptin/orphanin FQ (1 microM) via retrograde microdialysis, into the basolateral nucleus of the amygdala. Local infusion of nociceptin/orphanin FQ (1 microM) itself reduced noradrenaline release in the basolateral nucleus of the amygdala to about 70% of basal levels. These results indicate that a large part of basal release of noradrenaline in the basolateral nucleus of the amygdala is under tonic inhibitory control by endogenous nociceptin/orphanin FQ through the N/OFQ peptide receptors localized within the basolateral nucleus of the amygdala.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amygdala / drug effects*
  • Amygdala / metabolism
  • Animals
  • Dose-Response Relationship, Drug
  • Male
  • Neural Inhibition / drug effects*
  • Neural Inhibition / physiology
  • Norepinephrine / antagonists & inhibitors
  • Norepinephrine / metabolism*
  • Opioid Peptides / pharmacology*
  • Rats
  • Rats, Wistar
  • Synaptic Transmission / drug effects*
  • Synaptic Transmission / physiology

Substances

  • Opioid Peptides
  • nociceptin
  • Norepinephrine