title: SB-334867-A, a selective orexin-1 receptor antagonist, enhances taste aversion learning and blocks taste preference learning in rats.
abstract: Lateral hypothalamus (LH) has been proposed as a possible center for the anatomical convergence of gustatory and postingestive information relevant to taste aversion learning (TAL) and conditioned flavor preference (CFP). Orexin, a neuropeptide that mainly originates in neurons in lateral hypothalamic areas, was recently related to learning and memory processes. The present study was designed to analyze a possible relationship between the orexinergic system and taste learning. We studied the effect of intracerebroventricular administration of three doses (3, 6, and 12 μg/1 μl) of the selective orexin-1 receptor antagonist SB-334867-A on the acquisition of TAL induced by a single administration of LiCl. Infusion of SB-334867-A did not block this learning and appeared to enhance TAL in a two-bottle test. However, SB-334867-A (6 μg/1 μl) blocked taste preference learning when a flavor associated with saccharin (CS+) was offered on alternate days against a different flavor without saccharin (CS-), during three acquisition sessions. These results offer evidence of a relationship between the orexinergic system and taste learning; they tentatively suggest the possibility that endogenous orexin and gustatory and postingestive (visceral and oral) signals converge in brain areas relevant to the acquisition of taste learning.
authors.affiliation: Área de Psicobiología, Departamento de Psicología Experimental y Fisiología del Comportamiento, Facultad de Psicología, Campus de Cartuja s/n, Universidad de Granada, 18071 Granada, Spain. cristina@ugr.es
authors.forename: Cristina
authors.initials: C
authors.lastname: Mediavilla
authors.forename: Victoria
authors.initials: V
authors.lastname: Cabello
authors.forename: Severiano
authors.initials: S
authors.lastname: Risco
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001583:Benzoxazoles / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects; D008297:Male; D009287:Naphthyridines; D064446:Orexin Receptors; D051381:Rats; D017208:Rats, Wistar; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors*; D018013:Receptors, Neuropeptide / Q000037:antagonists & inhibitors*; D013649:Taste; D014508:Urea / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: C420062:1-(2-methylbenzoxazol-6-yl)-3-(1,5)naphthyridin-4-yl urea; D001583:Benzoxazoles; D009287:Naphthyridines; D064446:Orexin Receptors; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide; D014508:Urea