title: Influence of ghrelin on the central serotonergic signaling system in mice.
abstract: The central ghrelin signaling system engages key pathways of importance for feeding control, recently shown to include those engaged in anxiety-like behavior in rodents. Here we sought to determine whether ghrelin impacts on the central serotonin system, which has an important role in anxiety. We focused on two brain areas, the amygdala (of importance for the mediation of fear and anxiety) and the dorsal raphe (i.e. the site of origin of major afferent serotonin pathways, including those that project to the amygdala). In these brain areas, we measured serotonergic turnover (using HPLC) and the mRNA expression of a number of serotonin-related genes (using real-time PCR). We found that acute central administration of ghrelin to mice increased the serotonergic turnover in the amygdala. It also increased the mRNA expression of a number of serotonin receptors, both in the amygdala and in the dorsal raphe. Studies in ghrelin receptor (GHS-R1A) knock-out mice showed a decreased mRNA expression of serotonergic receptors in both the amygdala and the dorsal raphe, relative to their wild-type littermates. We conclude that the central serotonin system is a target for ghrelin, providing a candidate neurochemical substrate of importance for ghrelin's effects on mood.
authors.affiliation: Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden. Electronic address: caroline.hansson@gu.se.
authors.forename: Caroline
authors.initials: C
authors.lastname: Hansson
authors.affiliation: Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Mayte
authors.initials: M
authors.lastname: Alvarez-Crespo
authors.affiliation: Department of Molecular and Clinical Medicine, Institute of Medicine, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Taube
authors.affiliation: Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Karolina P
authors.initials: KP
authors.lastname: Skibicka
authors.affiliation: Department of Molecular and Clinical Medicine, Institute of Medicine, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Linnéa
authors.initials: L
authors.lastname: Schmidt
authors.affiliation: Department of Molecular and Clinical Medicine, Institute of Medicine, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Linda
authors.initials: L
authors.lastname: Karlsson-Lindahl
authors.affiliation: Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Emil
authors.initials: E
authors.lastname: Egecioglu
authors.affiliation: Department of Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Hans
authors.initials: H
authors.lastname: Nissbrandt
authors.affiliation: Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden.
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Dickson
mesh_terms: D000679:Amygdala / Q000378:metabolism*; D000818:Animals; D015870:Gene Expression; D054439:Ghrelin / Q000378:metabolism*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008995:Monoamine Oxidase / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011903:Raphe Nuclei / Q000378:metabolism*; D054440:Receptors, Ghrelin / Q000235:genetics / Q000378:metabolism; D011985:Receptors, Serotonin / Q000378:metabolism; D012701:Serotonin / Q000378:metabolism
chemical_list: D054439:Ghrelin; D006897:Hydroxyindoleacetic Acid; D008995:Monoamine Oxidase; D012333:RNA, Messenger; D054440:Receptors, Ghrelin; D011985:Receptors, Serotonin; D012701:Serotonin; C000592182:Ghsr protein, Mouse
keywords: Amygdala; Anxiety; Dorsal raphe; GHS-R1A; Serotonin; Serotonin receptors