title: An investigation of the neural mechanisms underlying the efficacy of the adjustable gastric band.
abstract: BACKGROUND
  The mechanisms via which adjustable gastric band (AGB) surgery provides effective and durable weight loss remain unclear.
  
  
  OBJECTIVE
  This study defines the role of sensory vagal fibers in the efficacy of the adjustable gastric banding using capsaicin to eliminate unmyelinated afferent fibers in the vagus nerve in a rodent model.
  
  
  METHODS
  University.
  
  
  METHODS
  A miniaturized AGB was fitted at the gastroesophageal junction of obese rats with either intact or sensory fiber depleted vagus nerves where deafferentation involved intraperitoneal (125 mg/kg) or topical (1% to the stomach) application of capsaicin. The extent of sensory fiber lesion was assessed using c-fiber-mediated reduction in cholecystokinin-induced feeding. Food intake, weight, and composition, as well as shifts in central neural activity (measured by elevation of Fos protein), were assessed after either control or AGB inflation with or without vagal deafferentation.
  
  
  RESULTS
  AGB inflation caused a significant reduction in food intake, weight, and fat mass (P<.05) in obese rats. The effect of AGB on these parameters was prevented in capsaicin pretreated (vagal sensory lesioned) rats. Elevations in neural activity in the nucleus of the solitary tract and parabrachial nucleus after AGB inflation were ameliorated in capsaicin-treated rats.
  
  
  CONCLUSIONS
  Vagal sensory fibers are integral to the efficacy of the AGB.
authors.affiliation: Department of Physiology, Monash University, Melbourne, Australia.
authors.forename: Aneta
authors.initials: A
authors.lastname: Stefanidis
authors.affiliation: Department of Physiology, Monash University, Melbourne, Australia.
authors.forename: Neal
authors.initials: N
authors.lastname: Forrest
authors.affiliation: Department of Surgery, Alfred Hospital, Melbourne, Australia; Centre for Obesity Research and Education, Monash University, Melbourne, Australia.
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Brown
authors.affiliation: Baker Heart and Diabetes Institute, Melbourne, Australia.
authors.forename: John B
authors.initials: JB
authors.lastname: Dixon
authors.affiliation: Centre for Obesity Research and Education, Monash University, Melbourne, Australia.
authors.forename: Paul B
authors.initials: PB
authors.lastname: O'Brien
authors.affiliation: Institute for Diabetes and Obesity, Hemholtz Zentrum München and Technische Universität München, Munich, Germany.
authors.lastname: Juliane Kampe
authors.affiliation: Department of Physiology, Monash University, Melbourne, Australia. Electronic address: Brian.Oldfield@monash.edu.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Oldfield
mesh_terms: D050154:Adiposity / Q000502:physiology; D000818:Animals; D001823:Body Composition / Q000502:physiology; D002211:Capsaicin / Q000494:pharmacology; D000070601:Diet, Carbohydrate Loading; D004435:Eating / Q000502:physiology; D002149:Energy Intake; D015391:Gastroplasty / Q000379:methods*; D008297:Male; D009767:Obesity, Morbid / Q000503:physiopathology* / Q000601:surgery; D017207:Rats, Sprague-Dawley; D012677:Sensation / Q000502:physiology; D018689:Sensory System Agents / Q000494:pharmacology; D014630:Vagus Nerve / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology
chemical_list: D018689:Sensory System Agents; D002211:Capsaicin
keywords: Animal model; Bariatric surgery; LAGB; Vagus nerve