title: Effects of aging on behavioral assessment performance: implications for clinically relevant models of neurological disease.
abstract: OBJECTIVE
  Despite the role of aging in development of neurological and neurodegenerative diseases, the effects of age are often disregarded in experimental design of preclinical studies. Functional assessment increases the clinical relevance of animal models of neurological disease and adds value beyond traditional histological measures. However, the relationship between age and functional impairment has not been systematically assessed through a battery of functional tests.
  
  
  METHODS
  In this study, various sensorimotor and behavioral tests were used to evaluate effects of aging on functional performance in naive animals. Sensorimotor measures included locomotor activity; Rotarod, inclined plane, and grip-strength testing; and modified Neurological Severity Score. The Morris water maze was used to examine differences in learning and memory, and the elevated plus maze and forced swim test were used to assess anxiety-like and depressive-like behaviors, respectively.
  
  
  RESULTS
  Older Sprague-Dawley rats (18-20 months) were found to perform significantly worse on the inclined plane tests, and they exhibited alterations in elevated-plus maze and forced swim test compared with young adult rats (3-4 months). Specifically, older rats exhibited reduced exploration of open arms in elevated plus maze and higher immobility time in forced swim test. Spatial acquisition and reference memory were diminished in older rats compared with those in young adult rats.
  
  
  CONCLUSIONS
  This study demonstrates clear differences between naive young adult and older animals, which may have implications in functional assessment for preclinical models of neurological disease.
authors: Department of Neurosurgery, West Virginia University, School of Medicine, Morgantown, West Virginia 26506-9183, USA.
authors: Ryan C
authors: RC
authors: Turner
authors: Michael J
authors: MJ
authors: Seminerio
authors: Zachary J
authors: ZJ
authors: Naser
authors: J Neal
authors: JN
authors: Ford
authors: Samantha J
authors: SJ
authors: Martin
authors: Rae R
authors: RR
authors: Matsumoto
authors: Charles L
authors: CL
authors: Rosen
authors: Jason D
authors: JD
authors: Huber
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D005260:Female; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology; D023421:Models, Animal; D009043:Motor Activity / Q000502:physiology; D009422:Nervous System Diseases / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013550:Swimming / Q000502:physiology