title: Ghrelin mediates anticipation to a palatable meal in rats.
abstract: Food anticipatory activity (FAA) is displayed in rats when access to food is restricted to a specific time frame of their circadian phase, a behavior thought to reflect both hunger and the motivation to eat. Rats also display FAA in a feeding schedule with ad libitum access to normal chow, but limited availability of a palatable meal, which is thought to involve mainly motivational aspects. The orexigenic hormone ghrelin has been implicated in FAA in rodents with restricted access to chow. Because ghrelin plays an important role not only in the control of food intake, but also in reward, we sought to determine the role of ghrelin in anticipation to a palatable meal. Plasma ghrelin levels of non-restricted rats that anticipated chocolate correlated positively with FAA and were increased compared with chow-fed control rats. Furthermore, centrally injected ghrelin increased, whereas an antagonist of the ghrelin receptor decreased, the anticipation to chocolate. Therefore, we hypothesize that central ghrelin signaling is able to mediate the motivational drive to eat.
authors.affiliation: Rudolf Magnus Institute of Neuroscience, Department of Neuroscience and Pharmacology, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Myrte
authors.initials: M
authors.lastname: Merkestein
authors.forename: Maike A D
authors.initials: MA
authors.lastname: Brans
authors.forename: Mieneke C M
authors.initials: MC
authors.lastname: Luijendijk
authors.forename: Johannes W
authors.initials: JW
authors.lastname: de Jong
authors.forename: Emil
authors.initials: E
authors.lastname: Egecioglu
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Dickson
authors.forename: Roger A H
authors.initials: RA
authors.lastname: Adan
mesh_terms: D000818:Animals; D059031:Anticipation, Psychological / Q000187:drug effects / Q000502:physiology; D001066:Appetite / Q000187:drug effects*; D005247:Feeding Behavior; D054439:Ghrelin / Q000097:blood / Q000378:metabolism* / Q000494:pharmacology; D008297:Male; D009042:Motivation; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D054440:Receptors, Ghrelin / Q000037:antagonists & inhibitors*
chemical_list: D054439:Ghrelin; D054440:Receptors, Ghrelin