title: Influence of leptin and GABAB-receptor agonist and antagonist on neurons of the hypothalamic infundibular nucleus in the chicken.
abstract: In birds and mammals, the neuroendocrine regulation of energy balance is conserved in many aspects. Despite significant similarities between the two groups, differences in the regulatory mechanisms were detected. The present study was performed to carry out investigations of the influence of human leptin and GABAB-receptor agonist and antagonist on the firing rate of neurons of the Nucleus infundibuli hypothalami in brain slices from juvenile chickens. For the first time, we demonstrated a clear, dose-related change in the firing rate of hypothalamic neurons in juvenile chickens after the acute application of recombinant human leptin (1, 10, and 100 nM). All investigated neurons increased their subsequent firing rate. Application of GABAB-receptor agonist baclofen (1 µM) blocked, while antagonist CGP 35348 (10 µM) increased the spontaneous neuronal activity. Simultaneous application of baclofen and leptin reduced the effect observed from single leptin application. This was not found after simultaneously application of leptin and CGP. Altogether, our results indicate that in bird brain slices, and exemplarily in those of the chicken, hypothalamic neurons show mammalian-like responsiveness after acute leptin and GABA application. GABAB-mechanisms involved in GABA release play a likely important role in the leptin-mediated effects on NI neurons via functional leptin receptors.
authors.affiliation: Faculty of Life Science, Institute of Biology, Humboldt-Universität zu Berlin, 10115, Berlin, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Bogatyrev
authors.affiliation: Faculty of Life Science, Institute of Biology, Humboldt-Universität zu Berlin, 10115, Berlin, Germany.|Department of Pharmacology, Faculty of Medicine, Medical University Sofia, Sofia, Bulgaria.
authors.forename: K S
authors.initials: KS
authors.lastname: Yakimova
authors.affiliation: Faculty of Life Science, Institute of Biology, Humboldt-Universität zu Berlin, 10115, Berlin, Germany. barbara.tzschentke@rz.hu-berlin.de.
authors.forename: B
authors.initials: B
authors.lastname: Tzschentke
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology*; D001418:Baclofen / Q000494:pharmacology; D002645:Chickens; D004305:Dose-Response Relationship, Drug; D005260:Female; D018756:GABA Antagonists / Q000494:pharmacology*; D058786:GABA-B Receptor Agonists / Q000494:pharmacology*; D066298:In Vitro Techniques; D020738:Leptin / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000187:drug effects*; D009943:Organophosphorus Compounds / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
chemical_list: D018756:GABA Antagonists; D058786:GABA-B Receptor Agonists; D020738:Leptin; D009943:Organophosphorus Compounds; D005680:gamma-Aminobutyric Acid; C066430:CGP 35348; D001418:Baclofen
keywords: Baclofen; CGP 35348; Chicken; Hypothalamus; Leptin