title: Dampened Mesolimbic Dopamine Function and Signaling by Saturated but not Monounsaturated Dietary Lipids.
abstract: Overconsumption of dietary fat is increasingly linked with motivational and emotional impairments. Human and animal studies demonstrate associations between obesity and blunted reward function at the behavioral and neural level, but it is unclear to what degree such changes are a consequence of an obese state and whether they are contingent on dietary lipid class. We sought to determine the impact of prolonged ad libitum intake of diets rich in saturated or monounsaturated fat, separate from metabolic signals associated with increased adiposity, on dopamine (DA)-dependent behaviors and to identify pertinent signaling changes in the nucleus accumbens (NAc). Male rats fed a saturated (palm oil), but not an isocaloric monounsaturated (olive oil), high-fat diet exhibited decreased sensitivity to the rewarding (place preference) and locomotor-sensitizing effects of amphetamine as compared with low-fat diet controls. Blunted amphetamine action by saturated high-fat feeding was entirely independent of caloric intake, weight gain, and plasma levels of leptin, insulin, and glucose and was accompanied by biochemical and behavioral evidence of reduced D1R signaling in the NAc. Saturated high-fat feeding was also tied to protein markers of increased AMPA receptor-mediated plasticity and decreased DA transporter expression in the NAc but not to alterations in DA turnover and biosynthesis. Collectively, the results suggest that intake of saturated lipids can suppress DA signaling apart from increases in body weight and adiposity-related signals known to affect mesolimbic DA function, in part by diminishing D1 receptor signaling, and that equivalent intake of monounsaturated dietary fat protects against such changes.
authors.affiliation: Centre de Recherche du CHUM and Montreal Diabetes Research Center, Montreal, QC, Canada.|Department of Physiology, Université de Montréal, Montreal, QC, Canada.
authors.forename: Cecile
authors.initials: C
authors.lastname: Hryhorczuk
authors.affiliation: Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, QC, Canada.
authors.forename: Marc
authors.initials: M
authors.lastname: Florea
authors.affiliation: Centre de Recherche du CHUM and Montreal Diabetes Research Center, Montreal, QC, Canada.
authors.forename: Demetra
authors.initials: D
authors.lastname: Rodaros
authors.affiliation: Department of Nutrition, Université de Montréal, Montreal, QC, Canada.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Poirier
authors.affiliation: Montreal Heart Institute, Montreal, QC, Canada.
authors.forename: Caroline
authors.initials: C
authors.lastname: Daneault
authors.affiliation: Department of Nutrition, Université de Montréal, Montreal, QC, Canada.|Montreal Heart Institute, Montreal, QC, Canada.
authors.forename: Christine
authors.initials: C
authors.lastname: Des Rosiers
authors.affiliation: Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, QC, Canada.
authors.forename: Andreas
authors.initials: A
authors.lastname: Arvanitogiannis
authors.affiliation: Centre de Recherche du CHUM and Montreal Diabetes Research Center, Montreal, QC, Canada.|Department of Medicine, Université de Montréal, Montreal, QC, Canada.
authors.forename: Thierry
authors.initials: T
authors.lastname: Alquier
authors.affiliation: Centre de Recherche du CHUM and Montreal Diabetes Research Center, Montreal, QC, Canada.|Center for Studies in Behavioral Neurobiology, Concordia University, Montreal, QC, Canada.|Department of Nutrition, Université de Montréal, Montreal, QC, Canada.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Fulton
mesh_terms: D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D003213:Conditioning, Psychological / Q000187:drug effects / Q000502:physiology; D059305:Diet, High-Fat / Q000009:adverse effects* / Q000379:methods; D004298:Dopamine / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism*; D000069463:Olive Oil / Q000008:administration & dosage*; D000073878:Palm Oil; D010938:Plant Oils / Q000008:administration & dosage*; D011897:Random Allocation; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000378:metabolism; D017447:Receptors, Dopamine D1 / Q000819:agonists / Q000378:metabolism*; D012201:Reward; D015398:Signal Transduction; D013037:Spatial Behavior / Q000187:drug effects / Q000502:physiology
chemical_list: D001552:Benzazepines; D000697:Central Nervous System Stimulants; D018491:Dopamine Agonists; D000069463:Olive Oil; D010938:Plant Oils; D018091:Receptors, AMPA; D017447:Receptors, Dopamine D1; D000073878:Palm Oil; C071262:SK&F 82958; D000661:Amphetamine; D004298:Dopamine