title: The alcohol-induced locomotor stimulation and accumbal dopamine release is suppressed in ghrelin knockout mice.
abstract: Ghrelin, the first endogenous ligand for the type 1A growth hormone secretagogue receptor (GHS-R1A), plays a role in energy balance, feeding behavior, and reward. Previously, we showed that pharmacologic and genetic suppression of the GHS-R1A attenuates the alcohol-induced stimulation, accumbal dopamine release, and conditioned place preference as well as alcohol consumption in mice, implying that the GHS-R1A is required for alcohol reward. The present study further elucidates the role of ghrelin for alcohol-induced dopamine release in nucleus accumbens and locomotor stimulation by means of ghrelin knockout mice. We found that the ability of alcohol to increase accumbal dopamine release in wild-type mice is not observed in ghrelin knockout mice. Furthermore, alcohol induced a locomotor stimulation in the wild-type mice and ghrelin knockout mice; however, the locomotor stimulation in homozygote mice was significantly lower than in the wild-type mice. The present series of experiments suggest that endogenous ghrelin may be required for the ability of alcohol to activate the mesolimbic dopamine system.
authors.affiliation: Section for Pharmacology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden. elisabet.jerlhag@pharm.gu.se
authors.forename: Elisabet
authors.initials: E
authors.lastname: Jerlhag
authors.forename: Sara
authors.initials: S
authors.lastname: Landgren
authors.forename: Emil
authors.initials: E
authors.lastname: Egecioglu
authors.forename: Suzanne L
authors.initials: SL
authors.lastname: Dickson
authors.forename: Jörgen A
authors.initials: JA
authors.lastname: Engel
mesh_terms: D000818:Animals; D004298:Dopamine / Q000378:metabolism* / Q000502:physiology; D000431:Ethanol / Q000494:pharmacology*; D054439:Ghrelin / Q000235:genetics*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009043:Motor Activity / Q000187:drug effects*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D054440:Receptors, Ghrelin / Q000502:physiology*
chemical_list: D054439:Ghrelin; D054440:Receptors, Ghrelin; D000431:Ethanol; D004298:Dopamine