Taste reward in rat models of obesity and gastric bypass surgery

Abstract

Event Abstract Back to Event Taste reward in rat models of obesity and gastric bypass surgery András Hajnal1* 1 Penn State University, College of Medicine, Department Neural and Behavioral Sciences, and Surgery, The Milton S. Hershey Medical Center, United States Currently, the Roux-en-Y gastric bypass surgery (GBS) is the most effective treatment for morbid obesity and associated type 2 diabetes. We used behavioral, electrophysiological and pharmacological methods in genetic (OLETF and Zucker) and diet-induced obese (DIO) rats to test the hypothesis that overeating in obesity and the success of GBS in reducing appetite are related to altered taste reward. Compared to pair-fed sham-operated (SH) controls, obese GBS rats expressed reduced 24-h 2-bottle preference and decreased 10-s lick responses for sucrose (0.3-1.5M) compared to SH controls. A similar effect was noted for other sweet compounds but not for salty, sour or bitter tastants. In lean rats, GBS did not alter responses to any stimulus tested. Extracellular recordings from taste-responsive neurons of the pontine parabrachial nucleus revealed an overall reduced responsiveness and a right-ward shift in concentration-responses to oral sucrose in obese compared to lean rats. These effects were reversed by GBS. In addition, obese rats demonstrated increased sensitivity to dopamine D2 receptor antagonist raclopride in reducing sucrose intake, an effect that was also alleviated by GBS. As a potential underlying mechanism we investigated secretion of intestinal hormones glucagon-like peptide-1 (GLP-1) and peptide YY in patients and obese rats and found that GBS increased postprandial plasma levels of both peptides. One-week treatment with GLP-1 analogue Exendin-4 reduced sweet taste preferences in DIO rats similar to the effect of GBS. These findings confirm obesity-related alterations in taste and reward functions for sweet and demonstrate the ability of GBS to alleviate these impairments. The effects of GBS on taste likely contribute to changes in food preferences observed in GBS patients. An improved understanding of the underlying mechanisms could help in developing effective non-invasive treatments for obesity. This research is supported by NIH grant DK080899. Conference: IBRO International Workshop 2010, Pécs, Hungary, 21 Jan - 23 Jan, 2010. Presentation Type: Oral Presentation Topic: Abstracts Citation: Hajnal A (2010). Taste reward in rat models of obesity and gastric bypass surgery. Front. Neurosci. Conference Abstract: IBRO International Workshop 2010. doi: 10.3389/conf.fnins.2010.10.00220 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 04 May 2010; Published Online: 04 May 2010. * Correspondence: András Hajnal, Penn State University, College of Medicine, Department Neural and Behavioral Sciences, and Surgery, The Milton S. Hershey Medical Center, Hershey, United States, ahajnal@psu.edu Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers András Hajnal Google András Hajnal Google Scholar András Hajnal PubMed András Hajnal Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.