Tonic inhibition by orphanin FQ/nociceptin of noradrenaline neurotransmission in the amygdala.
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.
Kawahara
Yukie
Y
Department of Pharmacology, Kurume University School of Medicine, Asahi-machi 67, Kurume 830-0011, Japan. yukikawa@med.kurume-u.ac.jp
Hesselink
Mayke B
MB
van Scharrenburg
Guus
G
Westerink
Ben H C
BH
D000679:Amygdala / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D004305:Dose-Response Relationship, Drug; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects* / Q000502:physiology; D009638:Norepinephrine / Q000037:antagonists & inhibitors / Q000378:metabolism*; D018847:Opioid Peptides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology; D000097629:Nociceptin
D009638:Norepinephrine; D018847:Opioid Peptides; D000097629:Nociceptin