title: The effect of orexin 1 and orexin 2 receptors antagonisms in the basolateral amygdala on memory processing in a passive avoidance task.
abstract: There is an extensive evidence concerning basolateral amygdala (BLA) function to hippocampal memory processing. However, few researches have addressed the orexinergic system roles in this modulation. Then, the present study aims at investigating the action of orexin 1 and 2 receptors in BLA on passive avoidance (PA) learning. Wistar male rats (n=79) were trained to avoid foot shock in one type of PA task. The rats were injected bilaterally into BLA, a selective orexin 1 receptor antagonist, SB-334867-A (3, 6, 12μg/0.5μl), and an orexin 2 receptor antagonist, TCS-OX2-29 (2.5, 5, 10μg/0.5μl), after training or before retrieval of the inhibitory avoidance task. Control rats received dimethyl sulfoxide at the same volume. The amount of learning was assessed 24h later. The time of the first entrance to the dark compartment and the total time spending in the light compartment were measured as criteria for the avoidance memory. The results showed that consolidation and retrieval were significantly impaired by SB-334867-A administration into BLA in 3, 6 and 12μg/0.5μl. However, TCS-OX2-29 in 2.5μg/0.5μl could not influence neither consolidation nor retrieval. The TCS-OX2-29 administration into BLA impaired memory retrieval in 5 and 10μg/0/5μl but not the consolidation. It gives the impression that orexinergic system of the BLA plays an important role in regulation of memory processing and learning in the rats.
authors.affiliation: Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology Research Center, Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Motahareh Rouhi
authors.initials: MR
authors.lastname: Ardeshiri
authors.affiliation: Department of Physiology, Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Neurophysiology Research Center, Medical School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Narges
authors.initials: N
authors.lastname: Hosseinmardi
authors.affiliation: Immunogenetic Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Department of Physiology and pharmacology,School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. Electronic address: akbari_esmaeil@mazums.ac.ir.
authors.forename: Esmaeil
authors.initials: E
authors.lastname: Akbari
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D066272:Basolateral Nuclear Complex / Q000187:drug effects* / Q000502:physiology; D001583:Benzoxazoles / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007546:Isoquinolines / Q000494:pharmacology*; D008297:Male; D008568:Memory / Q000187:drug effects*; D011939:Mental Recall / Q000187:drug effects; D009287:Naphthyridines; D000068796:Orexin Receptor Antagonists / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects; D014508:Urea / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: C420062:1-(2-methylbenzoxazol-6-yl)-3-(1,5)naphthyridin-4-yl urea; C572065:1-(3,4-dihydro-6,7-dimethoxy-2(1H)-isoquinolinyl)-3,3-dimethyl-2-((4-pyridinylmethyl)amino)-1-butanone; D001583:Benzoxazoles; D007546:Isoquinolines; D009287:Naphthyridines; D000068796:Orexin Receptor Antagonists; D011725:Pyridines; D014508:Urea
keywords: Basolateral amygdala; Learning; Memory; Orexin receptors; Passive avoidance learning