The role of dopamine in motivation for food in humans: implications for obesity.
Obesity is a major public health problem. The increasing number of obese individuals in the US adds urgency to the efforts to understand the mechanisms underlying pathological overeating. Imaging studies using positron emission tomography implicate the involvement of brain dopamine (DA) in normal and pathological food intake in humans. In normal body weight, fasting subjects, food presentation that could not be consumed was associated with increases in striatal extracellular DA, which provides evidence of an involvement of DA in non-hedonic motivational properties of food intake. In pathologically obese subjects, the authors showed reductions in striatal D2 receptor availability that were inversely associated with the weight of the subject. The involvement of the DA system in reward and reinforcement has led to the hypothesis that low brain DA activity in obese subjects predisposes them to excessive use of food. A better understanding of the role of the DA system in the motivation for food intake will help the development of better therapeutic interventions.
Wang
Gene-Jack
GJ
Medical Department, Brookhaven National Laboratory, Upton, NY 11973, USA. gjwang@bnl.gov
Volkow
Nora D
ND
Fowler
Joanna S
JS
D000818:Animals; D001066:Appetite / Q000187:drug effects / Q000502:physiology*; D001923:Brain Chemistry; D003342:Corpus Striatum / Q000378:metabolism; D004298:Dopamine / Q000502:physiology*; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000633:toxicity; D065127:Dopamine D2 Receptor Antagonists; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D001068:Feeding and Eating Disorders / Q000235:genetics / Q000503:physiopathology; D006801:Humans; D007031:Hypothalamus / Q000502:physiology; D008032:Limbic System / Q000502:physiology; D008774:Methylphenidate / Q000494:pharmacology; D009765:Obesity / Q000139:chemically induced / Q000188:drug therapy / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D051381:Rats; D011954:Receptors, Dopamine / Q000187:drug effects / Q000502:physiology; D017448:Receptors, Dopamine D2 / Q000235:genetics / Q000502:physiology; D012201:Reward; D012527:Satiation / Q000502:physiology; D019966:Substance-Related Disorders / Q000235:genetics / Q000503:physiopathology
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D065127:Dopamine D2 Receptor Antagonists; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D008774:Methylphenidate; D004298:Dopamine