title: A high-fat diet impairs cooling-evoked brown adipose tissue activation via a vagal afferent mechanism.
abstract: In dramatic contrast to rats on a control diet, rats maintained on a high-fat diet (HFD) failed to activate brown adipose tissue (BAT) during cooling despite robust increases in their BAT activity following direct activation of their BAT sympathetic premotor neurons in the raphe pallidus. Cervical vagotomy or blockade of glutamate receptors in the nucleus of the tractus solitarii (NTS) reversed the HFD-induced inhibition of cold-evoked BAT activity. Thus, a HFD does not prevent rats from mounting a robust, centrally driven BAT thermogenesis; however, a HFD does alter a vagal afferent input to NTS neurons, thereby preventing the normal activation of BAT thermogenesis to cooling. These results, paralleling the absence of cooling-evoked glucose uptake in the BAT of obese humans, reveal a neural mechanism through which consumption of a HFD contributes to reduced energy expenditure and thus to weight gain.
authors.affiliation: Department of Neurological Surgery, Oregon Health and Science University, Portland, Oregon maddench@ohsu.edu.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Madden
authors.affiliation: Department of Neurological Surgery, Oregon Health and Science University, Portland, Oregon.
authors.forename: Shaun F
authors.initials: SF
authors.lastname: Morrison
mesh_terms: D002001:Adipose Tissue, Brown / Q000187:drug effects / Q000294:innervation / Q000378:metabolism* / Q000503:physiopathology; D000344:Afferent Pathways; D000818:Animals; D003080:Cold Temperature; D059305:Diet, High-Fat; D004734:Energy Metabolism; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D005260:Female; D008297:Male; D009474:Neurons / Q000378:metabolism*; D065848:Nucleus Raphe Pallidus / Q000378:metabolism* / Q000503:physiopathology; D009765:Obesity / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017470:Receptors, Glutamate; D017552:Solitary Nucleus / Q000166:cytology; D013564:Sympathetic Nervous System / Q000503:physiopathology; D022722:Thermogenesis; D014628:Vagotomy; D014630:Vagus Nerve; D015430:Weight Gain
chemical_list: D018691:Excitatory Amino Acid Antagonists; D017470:Receptors, Glutamate
keywords: nucleus of the solitary tract; obesity; vagus nerve