title: Improvements in hippocampal-dependent memory and microglial infiltration with calorie restriction and gastric bypass surgery, but not with vertical sleeve gastrectomy.
abstract: BACKGROUND
  Much recent evidence suggest that obesity and related comorbidities contribute to cognitive decline, including the development of non age-related dementia and Alzheimer's disease. Obesity is a serious threat to public health, and few treatments offer proven long-term weight loss. In fact, bariatric surgery remains the most effective long-term therapy to reduce weight and alleviate other aspects of the metabolic syndrome (MetS). Unlike the demonstrated benefits of caloric restriction to prevent weight gain, few if any studies have compared various means of weight loss on central nervous system function and hippocampal-dependent cognitive processes.
  
  
  RESULTS
  Our studies comprise the first direct comparisons of caloric restriction to two bariatric surgeries (Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG)) on cognitive function. Weight loss following caloric restriction, RYGB and VSG was associated with generalized improvements in metabolic health and hippocampal-dependent learning, as measured in the radial arm maze and spontaneous alternation tests. However, VSG-treated rats exhibited deficits on spatial learning tasks in the Morris water maze. In addition, whereas VSG animals had elevated hippocampal inflammation, comparable to that of obese controls, RYGB and calorie-restricted (pair-fed, PF) controls exhibited an amelioration of inflammation, as measured by the microglial protein ionized calcium binding adaptor molecule 1 (IBA1). We also assessed whether GHR (ghrelin) replacement would attenuate hippocampal inflammation in VSG, as post-surgical GHR levels are significantly reduced in VSG relative to RYGB and PF rats. However, GHR treatment did not attenuate the hippocampal inflammation.
  
  
  CONCLUSIONS
  Although VSG was comparably effective at reducing body weight and improving glucose regulation as RYGB, VSG did not appear to confer an equal benefit on cognitive function and markers of inflammation.
authors.affiliation: Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, The University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: B E
authors.initials: BE
authors.lastname: Grayson
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, The University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Fitzgerald
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, The University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Hakala-Finch
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, The University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: V M
authors.initials: VM
authors.lastname: Ferris
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, The University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: D P
authors.identifier: 0000000245512697
authors.initials: DP
authors.lastname: Begg
authors.affiliation: Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, The University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: J
authors.initials: J
authors.lastname: Tong
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, The University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Woods
authors.affiliation: Division of Endocrinology, Diabetes and Metabolism, Department of Internal Medicine, The University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Seeley
authors.affiliation: Center for Behavioral Neuroscience, College of Arts and Sciences, American University, Washington, DC, USA.
authors.forename: T L
authors.initials: TL
authors.lastname: Davidson
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, The University of Cincinnati College of Medicine, Cincinnati, OH, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Benoit
mesh_terms: D000818:Animals; D001786:Blood Glucose; D001835:Body Weight; D031204:Caloric Restriction; D003072:Cognition Disorders / Q000473:pathology* / Q000601:surgery; D004195:Disease Models, Animal; D005743:Gastrectomy / Q000379:methods; D015390:Gastric Bypass; D006624:Hippocampus / Q000473:pathology*; D006706:Homeostasis; D007249:Inflammation / Q000473:pathology* / Q000601:surgery; D008297:Male; D018782:Maze Learning; D051381:Rats; D020318:Rats, Long-Evans; D012074:Remission Induction; D015431:Weight Loss
chemical_list: D001786:Blood Glucose