title: Role of the blood-brain barrier in the evolution of feeding and cognition.
abstract: The blood-brain barrier (BBB) regulates the blood-to-brain passage of gastrointestinal hormones, thus informing the brain about feeding and nutritional status. Disruption of this communication results in dysregulation of feeding and body weight control. Leptin, which crosses the BBB to inform the CNS about adiposity, provides an example. Impaired leptin transport, especially coupled with central resistance, results in obesity. Various substances/conditions regulate leptin BBB transport. For example, triglycerides inhibit leptin transport. This may represent an evolutionary adaptation in that hypertriglyceridemia occurs during starvation. Inhibition of leptin, an anorectic, during starvation could have survival advantages. The large number of other substances that influence feeding is explained by the complexity of feeding. This complexity includes cognitive aspects; animals in the wild are faced with cost/benefit analyses to feed in the safest, most economical way. This cognitive aspect partially explains why so many feeding substances affect neurogenesis, neuroprotection, and cognition. The relation between triglycerides and cognition may be partially mediated through triglyceride's ability to regulate the BBB transport of cognitively active gastrointestinal hormones such as leptin, insulin, and ghrelin.
authors.affiliation: GRECC, Veterans Affairs Puget Sound Health Care System and Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington 98108, USA. wabanks1@uw.edu
authors.forename: William A
authors.initials: WA
authors.lastname: Banks
mesh_terms: D050154:Adiposity; D000818:Animals; D001692:Biological Transport; D001812:Blood-Brain Barrier / Q000502:physiology*; D001835:Body Weight; D001921:Brain / Q000378:metabolism; D003071:Cognition; D005247:Feeding Behavior; D005768:Gastrointestinal Hormones / Q000378:metabolism*; D054439:Ghrelin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D020738:Leptin / Q000172:deficiency / Q000378:metabolism*; D051379:Mice; D014280:Triglycerides / Q000378:metabolism
chemical_list: D005768:Gastrointestinal Hormones; D054439:Ghrelin; D007328:Insulin; D020738:Leptin; D014280:Triglycerides