کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5923534 | 1571168 | 2015 | 9 صفحه PDF | دانلود رایگان |
- Flavor preferences are conditioned by sugar and fat in mice.
- Ghrelin signaling is implicated in food reward processing.
- Ghrelin receptor-deficient mice displayed normal flavor conditioning.
- Ghrelin receptor antagonism did not block sugar-conditioned flavor preferences.
- Ghrelin signaling is not essential for sugar or fat conditioned flavor preferences.
The oral and post-oral actions of sugar and fat stimulate intake and condition flavor preferences in rodents through a process referred to as appetition. Ghrelin is implicated in food reward processing, and this study investigated its involvement in nutrient conditioning in mice. In Exp. 1 ghrelin receptor-null (GHSR-null) and C57BL/6 wildtype (WT) mice learned to prefer a flavor (CS+) mixed into 8% glucose over another flavor (CSâ) mixed into a “sweeter” but non-nutritive 0.1% sucralose + saccharin (S + S) solution. In Exp. 2 treating WT mice with a ghrelin receptor antagonist [(D-Lys3)-GHRP-6] during flavor training did not prevent them from learning to prefer the CS+ glucose over the CSâ S + S flavor. GHSR-null and WT mice were trained in Exp. 3 to drink a CS+ paired with intragastric (IG) infusion of 16% glucose and a CSâ paired with IG water. Both groups drank more CS+ than CSâ in training and preferred the CS+ to CSâ in a choice test. The same (Exp. 4) and new (Exp. 5) GHSR-null and WT mice learned to prefer a CS+ flavor paired with IG fat (Intralipid) over a CSâ flavor paired with IG water. GHSR-null and WT mice also learned to prefer a CS+ flavor added to 8% fructose over a CSâ added to water. Together, these results indicate that ghrelin receptor signaling is not required for flavor preferences conditioned by the oral or post-oral actions of sugar and fat. This contrasts with other findings implicating ghrelin signaling in food reward processing and food-conditioned place preferences.
Journal: Physiology & Behavior - Volume 149, 1 October 2015, Pages 14-22