title: Brainstem nutrient sensing in the nucleus of the solitary tract inhibits feeding.
abstract: Direct detection of circulating nutrients by the central nervous system has been implicated in the regulation of energy balance, and the mediobasal hypothalamus is considered as the primary sensing site mediating these effects. Neurons sensitive to energyrelated signals have also been identified outside the hypothalamus, particularly within the caudomedial nucleus of the solitary tract (cmNTS) in brainstem, but the consequences of direct cmNTS nutrient detection on energy balance remain poorly characterized. Here we determined the behavioral and metabolic consequences of direct L-leucine detection by the cmNTS and investigated the intracellular signaling and neurochemical pathways implicated in cmNTS L-leucine sensing in rats. Our results support the distributed nature of central nutrient detection, evidence a role for the cmNTS S6K1 pathway in the regulation of meal size and body weight, and suggest that the cmNTS integrates direct cmNTS nutrient detection with gut-derived, descending forebrain, and adiposity signals of energy availability to regulate food intake.
authors.affiliation: Department of Medicine, Diabetes Research Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
authors.forename: Clemence
authors.initials: C
authors.lastname: Blouet
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Schwartz
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004435:Eating / Q000187:drug effects*; D004734:Energy Metabolism; D007031:Hypothalamus / Q000378:metabolism; D007930:Leucine / Q000494:pharmacology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D051381:Rats; D019893:Ribosomal Protein S6 Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D017552:Solitary Nucleus / Q000201:enzymology / Q000378:metabolism*
chemical_list: D019893:Ribosomal Protein S6 Kinases; C526901:Rps6kb1 protein, rat; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D007930:Leucine