nutrients Article Ghrelin Receptors Enhance Fat Taste Responsiveness in Female Mice Ashley N. Calder 1,† , Tian Yu 2,†, Naima S. Dahir 1, Yuxiang Sun 3 and Timothy A. Gilbertson 4,* 1 Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32827, USA;
[email protected] (A.N.C.);
[email protected] (N.S.D.) 2 Department of Cell & Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
[email protected] 3 Department of Nutrition, Texas A&M University, College Station, TX 77843, USA;
[email protected] 4 Department of Internal Medicine, College of Medicine, University of Central Florida, Orlando, FL 32827, USA * Correspondence:
[email protected]; Tel.: +1-321-266-7245 † These authors contributed equally to this work. Abstract: Ghrelin is a major appetite-stimulating neuropeptide found in circulation. While its role in increasing food intake is well known, its role in affecting taste perception, if any, remains unclear. In this study, we investigated the role of the growth hormone secretagogue receptor’s (GHS-R; a ghrelin receptor) activity in the peripheral taste system using feeding studies and conditioned taste aversion assays by comparing wild-type and GHS-R-knockout models. Using transgenic mice expressing enhanced green fluorescent protein (GFP), we demonstrated GHS-R expression in the taste system in relation phospholipase C ß2 isotype (PLCβ2; type II taste cell marker)- and glutamate decarboxylase type 67 (GAD67; type III taste cell marker)-expressing cells using immunohistochemistry. We observed high levels of co-localization between PLCβ2 and GHS-R within the taste system, while GHS-R rarely co-localized in GAD67-expressing cells.