title: Identifying novel phenotypes of vulnerability and resistance to activity-based anorexia in adolescent female rats.
abstract: OBJECTIVE
  Activity-based anorexia is a translational rodent model that results in severe weight loss, hyperactivity, and voluntary self-starvation. The goal of our investigation was to identify vulnerable and resistant phenotypes of activity-based anorexia in adolescent female rats.
  
  
  METHODS
  Sprague-Dawley rats were maintained under conditions of restricted access to food (N = 64; or unlimited access, N = 16) until experimental exit, predefined as a target weight loss of 30-35% or meeting predefined criteria for animal health. Nonlinear mixed effects statistical modeling was used to describe wheel running behavior, time to event analysis was used to assess experimental exit, and a regressive partitioning algorithm was used to classify phenotypes.
  
  
  RESULTS
  Objective criteria were identified for distinguishing novel phenotypes of activity-based anorexia, including a vulnerable phenotype that conferred maximal hyperactivity, minimal food intake, and the shortest time to experimental exit, and a resistant phenotype that conferred minimal activity and the longest time to experimental exit.
  
  
  CONCLUSIONS
  The identification of objective criteria for defining vulnerable and resistant phenotypes of activity-based anorexia in adolescent female rats provides an important framework for studying the neural mechanisms that promote vulnerability to or protection against the development of self-starvation and hyperactivity during adolescence. Ultimately, future studies using these novel phenotypes may provide important translational insights into the mechanisms that promote these maladaptive behaviors characteristic of anorexia nervosa.
authors.affiliation: Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York; Department of Psychiatry, New York State Psychiatric Institute, New York.
authors.forename: Nicole C
authors.initials: NC
authors.lastname: Barbarich-Marsteller
authors.forename: Mark D
authors.initials: MD
authors.lastname: Underwood
authors.forename: Richard W
authors.initials: RW
authors.lastname: Foltin
authors.forename: Michael M
authors.initials: MM
authors.lastname: Myers
authors.forename: B Timothy
authors.initials: BT
authors.lastname: Walsh
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Barrett
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Marsteller
mesh_terms: D000818:Animals; D000855:Anorexia / Q000503:physiopathology*; D000856:Anorexia Nervosa; D001522:Behavior, Animal; D001835:Body Weight; D004195:Disease Models, Animal; D004435:Eating; D005260:Female; D006801:Humans; D009043:Motor Activity; D010641:Phenotype; D051381:Rats; D017207:Rats, Sprague-Dawley; D013217:Starvation; D015431:Weight Loss
keywords: activity-based anorexia; adolescence; animal model; anorexia nervosa; exercise; food restriction; hyperactivity; rat; resistance; vulnerability