title: Gabaergic control of anxiety-like behavior, but not food intake, induced by ghrelin in the intermediate medial mesopallium of the neonatal chick.
abstract: Ghrelin (Grh) is an endogenous ligand of the growth hormone secretagogue receptor. In neonatal chicks, central Ghr induces anxiogenic-like behavior but strongly inhibits food intake. The intermediate medial mesopallium (IMM) of the chick forebrain has been identified to be a site of the memory formation, and the modulation of the GABAA receptors that are present here modifies the expression of behavior. Thus, the GABAergic system may constitute a central pathway for Ghr action in regulating the processes of food intake and stress-related behaviors. Therefore, we investigated if the effect of systemic administration of bicuculline (GABAA receptor antagonist) and diazepam (benzodiazepine receptor agonist) on the anxiety in an Open Field test and inhibition in food intake induced by Grh (30pmol) when injected into IMM, were mediated by GABAergic transmission. In Open Field test, bicuculline was able to block the anxiogenic-like behavior induced by Ghr, whereas diazepam did not produce it. However, the co-administration of bicuculline or diazepam plus Ghr did not show any change in food intake at 30, 60 and 120min after injection compared to Ghr alone. Our results indicate for the first time that Ghr, injected into the forebrain IMM area, induces an anxiogenic-like behavior, which was blocked by bicuculline but not diazepam, thus suggesting that Ghr plays an important role in the response pattern to acute stressor, involving the possible participation of the GABAergic system. Nevertheless, as neither drug affected the hypophagia induced by intra-IMM Ghr, this suggests that it may be mediated by different mechanisms.
authors.affiliation: Departamento de Química, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Instituto de Investigaciones Biológicas y Tecnológicas (IIByT-CONICET), Av. Vélez Sarsfield 1611, 5016 Córdoba, Argentina.
authors.forename: M S
authors.initials: MS
authors.lastname: Gastón
authors.affiliation: Section of Functional Pharmacology, Department of Neuroscience, Uppsala University, Institutionen för Neurovetenskap BMC, Box 593, 751 24 Uppsala, Sweden.
authors.forename: H B
authors.initials: HB
authors.lastname: Schiöth
authors.affiliation: Departamento de Farmacología, Facultad de Ciencias Químicas, Instituto de Farmacología Experimental Córdoba (IFEC-CONICET), Haya de la Torre y Medina Allende, Universidad Nacional de Córdoba, Ciudad Universitaria, 5016 Córdoba, Argentina.
authors.forename: S R
authors.initials: SR
authors.lastname: De Barioglio
authors.affiliation: Departamento de Química, Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Instituto de Investigaciones Biológicas y Tecnológicas (IIByT-CONICET), Av. Vélez Sarsfield 1611, 5016 Córdoba, Argentina. Electronic address: nsalvatierra@efn.uncor.edu.
authors.forename: N A
authors.initials: NA
authors.lastname: Salvatierra
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001007:Anxiety / Q000139:chemically induced / Q000378:metabolism*; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D054022:Cerebrum / Q000187:drug effects / Q000378:metabolism*; D002645:Chickens; D004435:Eating / Q000187:drug effects / Q000502:physiology*; D005260:Female; D054439:Ghrelin / Q000008:administration & dosage / Q000494:pharmacology / Q000502:physiology*; D008297:Male; D011963:Receptors, GABA-A / Q000502:physiology*
chemical_list: D054439:Ghrelin; D011963:Receptors, GABA-A
keywords: Acute stress; Food intake; GABA(A) receptor; Ghrelin; Intermediate medial mesopallium