Central administration of ghrelin alters emotional responses in rats: behavioural, electrophysiological and molecular evidence
2011 (English)In: Neuroscience, ISSN 0306-4522, E-ISSN 1873-7544, Vol. 180, 201-211 p.Article in journal (Refereed) Published
The orexigenic and pro-obesity hormone ghrelin targets key hypothalamic and mesolimbic circuits involved in energy balance, appetite and reward. Given that such circuits are closely integrated with those regulating mood and cognition, we sought to determine whether chronic (>2 weeks) CNS exposure to ghrelin alters anxiety- and depression-like behaviour in rats as well as some physiological correlates. Rats bearing chronically implanted i.c.v. catheters were treated with ghrelin (10 μg/d) or vehicle for 4 weeks. Tests used to assess anxiety- and depression-like behaviour were undertaken during weeks 3-4 of the infusion. These revealed an increase in anxiety- and depression-like behaviour in the ghrelin-treated rats relative to controls. At the end of the 4-week infusion, brains were removed and the amygdala dissected for subsequent qPCR analysis that revealed changes in expression of a number of genes representing key systems implicated in these behavioural changes. Finally, given the key role of the dorsal raphe serotonin system in emotional reactivity, we examined the electrophysiological response of dorsal raphe neurons after a ghrelin challenge, and found mainly inhibitory responses in this region. We demonstrate that the central ghrelin signalling system is involved in emotional reactivity in rats, eliciting pro-anxiety and pro-depression effects and have begun to explore novel target systems for ghrelin that may be of importance for these effects.
Place, publisher, year, edition, pages
Elsevier, 2011. Vol. 180, 201-211 p.
emotional reactivity, anxiety, depression; memory, GHS-R1A, serotonin
IdentifiersURN: urn:nbn:se:umu:diva-82363DOI: 10.1016/j.neuroscience.2011.02.002ISI: 000289395600021PubMedID: 21303683OAI: oai:DiVA.org:umu-82363DiVA: diva2:660966
FunderSwedish Society for Medical Research (SSMF), VR 2006-5663Swedish Society for Medical Research (SSMF), 2009-S266
Funding was provided by the Swedish Research Council for Medicine (VR 2006-5663; 2009-S266), European Commission 7th Framework (FP7-HEALTH-2009-241592; FP7-KBBE-2009-3-245009), FOUIALF Goteborg (SU7601), Fredrik och Ingrid Thurings Stiftelse, Konrad och Helgfrid Johanssons food and the Swedish Institute and the Swedish Foundation for Strategic Research to Sahlgrenska Center for Cardiovascular and Metabolic Research (A305-188).2013-10-312013-10-312013-11-05Bibliographically approved