title: The orexin-1 receptor antagonist SB-334867 decreases anxiety-like behavior and c-Fos expression in the hypothalamus of rats exposed to cat odor.
abstract: Increasing evidence suggests that the orexin system is involved in modulating anxiety, and we have recently shown that cat odor-induced anxiety in rats is attenuated by the orexin receptor antagonist SB-334867. In the current experiment, c-Fos expression was used to map changes in neuronal activation following SB-334867 administration in the cat odor anxiety model. Male Wistar rats were exposed to cat odor with or without SB-334867 pre-treatment (10 mg/kg, i.p.). A naïve control group not exposed to cat odor was also used. Following cat odor exposure, brains were processed for c-Fos expression. Vehicle-treated rats showed an increase in anxiety-like behaviors (increased hiding and decreased approach toward the cat odor), and increased c-Fos expression in the posteroventral medial amygdala (MePV), paraventricular hypothalamus (PVN) and dorsal premammillary nucleus (PMd). In rats pretreated with SB-334867, approach scores increased and c-Fos expression decreased in the PVN and PMd. These results provide both behavioral and neuroanatomical evidence for the attenuation of cat odor-induced anxiety in rats via the orexin system.
authors.affiliation: Department of Psychology C3A, Macquarie University, NSW 2109, Australia.
authors.forename: M W
authors.initials: MW
authors.lastname: Vanderhaven
authors.affiliation: Department of Psychology C3A, Macquarie University, NSW 2109, Australia.
authors.forename: J L
authors.initials: JL
authors.lastname: Cornish
authors.affiliation: Department of Psychology C3A, Macquarie University, NSW 2109, Australia. Electronic address: Lauren.Staples@mq.edu.au.
authors.forename: L G
authors.initials: LG
authors.lastname: Staples
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001007:Anxiety / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D001583:Benzoxazoles / Q000627:therapeutic use*; D002415:Cats; D004195:Disease Models, Animal; D005786:Gene Expression Regulation / Q000187:drug effects*; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009287:Naphthyridines; D009812:Odorants; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D018013:Receptors, Neuropeptide / Q000037:antagonists & inhibitors; D014508:Urea / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: C420062:1-(2-methylbenzoxazol-6-yl)-3-(1,5)naphthyridin-4-yl urea; D001583:Benzoxazoles; D009287:Naphthyridines; D016760:Proto-Oncogene Proteins c-fos; D018013:Receptors, Neuropeptide; D014508:Urea
keywords: Defensive behavior; Dorsal premammillary nucleus; Orexin; Paraventricular hypothalamus; SB-334867; c-Fos immunohistochemistry