title: Wheel running reduces high-fat diet intake, preference and mu-opioid agonist stimulated intake.
abstract: The ranges of mechanisms by which exercise affects energy balance remain unclear. One potential mechanism may be that exercise reduces intake and preference for highly palatable, energy dense fatty foods. The current study used a rodent wheel running model to determine whether and how physical activity affects HF diet intake/preference and reward signaling. Experiment 1 examined whether wheel running affected the ability of intracerebroventricular (ICV) μ opioid receptor agonist D-Ala2, NMe-Phe4, Glyol5-enkephalin (DAMGO) to increase HF diet intake. Experiment 2 examined the effects of wheel running on the intake of and preference for a previously preferred HF diet. We also assessed the effects of wheel running and diet choice on mesolimbic dopaminergic and opioidergic gene expression. Experiment 1 revealed that wheel running decreased the ability of ICV DAMGO administration to stimulate HF diet intake. Experiment 2 showed that wheel running suppressed weight gain and reduced intake and preference for a previously preferred HF diet. Furthermore, the mesolimbic gene expression profile of wheel running rats was different from that of their sedentary paired-fed controls but similar to that of sedentary rats with large HF diet consumption. These data suggest that alterations in preference for palatable, energy dense foods play a role in the effects of exercise on energy homeostasis. The gene expression results also suggest that the hedonic effects of exercise may substitute for food reward to limit food intake and suppress weight gain.
authors: Department of Psychology, University of Illinois-Urbana Champaign, 725 Psychology Building, 603 E. Daniel Street, M/C 716, Champaign, IL 61820, USA; Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA. Electronic address: ncliang8@illinois.edu.
authors: Nu-Chu
authors: NC
authors: Liang
authors: Department of Animal Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901, USA.
authors: Nicholas T
authors: NT
authors: Bello
authors: Department of Psychiatry and Behavioral Sciences, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA.
authors: Timothy H
authors: TH
authors: Moran
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D002408:Catheters, Indwelling; D015331:Cohort Studies; D059305:Diet, High-Fat / Q000009:adverse effects / Q000523:psychology; D004435:Eating / Q000187:drug effects / Q000502:physiology*; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology*; D005518:Food Preferences / Q000187:drug effects / Q000502:physiology*; D020869:Gene Expression Profiling; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology; D017397:Prefrontal Cortex / Q000187:drug effects / Q000502:physiology; D017207:Rats, Sprague-Dawley; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000378:metabolism; D012420:Running / Q000502:physiology*; D017557:Ventral Tegmental Area / Q000187:drug effects / Q000502:physiology; D015430:Weight Gain / Q000187:drug effects / Q000502:physiology
chemical_list: D000701:Analgesics, Opioid; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
keywords: Dopamine; High fat diet; Mesolimbic system; Opioid; Physical activity; Wheel running