title: MCH receptor deletion does not impair glucose-conditioned flavor preferences in mice.
abstract: The post-oral actions of glucose stimulate intake and condition flavor preferences in rodents. Hypothalamic melanin-concentrating hormone (MCH) neurons are implicated in sugar reward, and this study investigated their involvement in glucose preference conditioning in mice. In Exp. 1 MCH receptor 1 knockout (KO) and C57BL/6 wildtype (WT) mice learned to prefer 8% glucose over an initially more-preferred non-nutritive 0.1% sucralose+saccharin (S+S) solution. In contrast, the KO and WT mice preferred S+S to 8% fructose, which is consistent with this sugar's weak post-oral reinforcing action. In Exp. 2 KO and WT mice were trained to drink a flavored solution (CS+) paired with intragastric (IG) infusion of 16% glucose and a different flavored solution (CS-) paired with IG water. Both groups drank more CS+ than CS- in training and preferred the CS+ to CS- in a 2-bottle test. These results indicate that MCH receptor signaling is not required for flavor preferences conditioned by the post-oral actions of glucose. This contrasts with other findings implicating MCH signaling in other types of sugar reward processing.
authors.affiliation: Department of Psychology, Brooklyn College of the City University of New York, Brooklyn, NY, USA; Behavioral and Cognitive Neuroscience Cluster, Psychology Doctoral Program, The Graduate School, City University of New York, New York, NY, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Sclafani
authors.affiliation: Department of Neurology, Inselspital University Hospital, University of Bern, Bern, Switzerland; Department of Clinical Research (DKF), University of Bern, Bern, Switzerland.
authors.forename: Antoine
authors.initials: A
authors.lastname: Adamantidis
authors.affiliation: Department of Psychology, Brooklyn College of the City University of New York, Brooklyn, NY, USA.
authors.forename: Karen
authors.initials: K
authors.lastname: Ackroff
mesh_terms: D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology*; D005260:Female; D005518:Food Preferences / Q000502:physiology*; D005947:Glucose / Q000008:administration & dosage*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011979:Receptors, Pituitary Hormone / Q000172:deficiency* / Q000235:genetics; D012439:Saccharin / Q000008:administration & dosage; D013549:Sweetening Agents; D013649:Taste / Q000502:physiology
chemical_list: D011979:Receptors, Pituitary Hormone; D013549:Sweetening Agents; C092274:melanin-concentrating hormone receptor; D012439:Saccharin; D005947:Glucose
keywords: Flavor conditioning; Fructose; Glucose; Intragastric; Melanin-concentrating hormone; Non-nutritive sweetener