Role of amygdaloid nuclei in the anxiolytic-like effect of nociceptin/orphanin FQ in rats.
We investigated the mechanism underlying the anxiolytic actions of the neuropeptide nociceptin/orphanin FQ (N/OFQ) using the elevated plus-maze test and T-maze test. Microinfusions of N/OFQ (10 or 32pmol) into the central amygdala (ACE) increased the time spent in the open arms of the elevated plus-maze (anxiolytic-like effects), whereas microinfusions of N/OFQ (10, 32 or 100 pmol) into the basolateral amygdala (ABL) did not affect the time spent in the open arms. Moreover, microinfusions of N/OFQ (32 pmol) into the ACE impaired escape performance from the open arms of the elevated T-maze (anxiolytic-like effects), but did not change inhibitory avoidance of the open arms. A non-peptidyl N/OFQ receptor (NOP) antagonist, J-113397(1-[(3R,4R)-1-cyclooctylmethyl-3-hydroxymethyl-4-piperidyl]-3-ethyl-1,3-dihydro-2H-benzimidazol-2-one) (10 mg/kg, s.c.), blocked the anxiolytic-like effects induced by N/OFQ. These results indicate that the anxiolytic-like effects of N/OFQ might be due to impaired escape performance from the open arms and it implicates the N/OFQ system within the ACE in the mediation of panic action.
Uchiyama
Hidemori
H
Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Toda
Akihisa
A
Hiranita
Takato
T
Watanabe
Shigenori
S
Eyanagi
Reiko
R
D000679:Amygdala / Q000187:drug effects* / Q000378:metabolism* / Q000503:physiopathology; D000818:Animals; D014151:Anti-Anxiety Agents / Q000378:metabolism / Q000494:pharmacology*; D001007:Anxiety / Q000188:drug therapy; D001008:Anxiety Disorders / Q000188:drug therapy* / Q000378:metabolism* / Q000503:physiopathology; D001562:Benzimidazoles / Q000494:pharmacology; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D008845:Microinjections; D018847:Opioid Peptides / Q000378:metabolism / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014665:Vasodilator Agents / Q000494:pharmacology; D000097629:Nociceptin
D014151:Anti-Anxiety Agents; D001562:Benzimidazoles; D018847:Opioid Peptides; D010880:Piperidines; D014665:Vasodilator Agents; D000097629:Nociceptin; C402921:J 113397