title: A high-fat meal, or intraperitoneal administration of a fat emulsion, increases extracellular dopamine in the nucleus accumbens.
abstract: Evidence links dopamine (DA) in the nucleus accumbens (NAc) shell to the ingestion of palatable diets. Less is known, however, about the specific relation of DA to dietary fat and circulating triglycerides (TG), which are stimulated by fat intake and promote overeating. The present experiments tested in Sprague-Dawley rats whether extracellular levels of NAc DA increase in response to acute access to fat-rich food or peripheral injection of a fat emulsion and, if so, whether this is related to caloric intake or elevated circulating lipids. When rats consumed more calories of a high-fat meal compared with a low-fat meal, there was a significant increase in extracellular accumbens DA (155% vs. 119%). Systemic injection of a fat emulsion, which like a high-fat diet raises circulating TG but eliminates the factor of taste and allows for the control of caloric intake, also significantly increased extracellular levels of DA (127%) compared to an equicaloric glucose solution (70%) and saline (85%). Together, this suggests that a rise in circulating TG may contribute to the stimulatory effect of a high-fat diet on NAc DA.
authors: Laboratory of Behavioral Physiology, School of Medicine, University of Los Andes, Mérida 5101-A, Venezuela. radap@ula.ve.
authors: Pedro
authors: P
authors: Rada
authors: Department of Psychology and Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA. navena@ufl.edu.
authors: Nicole M
authors: NM
authors: Avena
authors: Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY 10065, USA. jbarson@rockefeller.edu.
authors: Jessica R
authors: JR
authors: Barson
authors: Department of Psychology and Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA.
authors: Bartley G
authors: BG
authors: Hoebel
authors: Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY 10065, USA. leibow@rockefeller.edu.
authors: Sarah F
authors: SF
authors: Leibowitz