title: Temporal effects of environmental enrichment-mediated functional improvement after experimental traumatic brain injury in rats.
abstract: BACKGROUND
  Environmental enrichment (EE) enhances motor and cognitive performance after traumatic brain injury (TBI). However, whether the EE-mediated benefits are time dependent and task specific is unclear. A preliminary study, in which only half of the possible temporal manipulations were evaluated, revealed that the beneficial effects of enrichment were only observed when provided concurrently with specific training (ie, motor or cognitive), suggesting task-specific dependence.
  
  
  OBJECTIVE
  To further assess the effects of time of initiation and duration of EE on neurobehavioral recovery after TBI by evaluating and directly comparing all the temporal permutations.
  
  
  METHODS
  Anesthetized adult male rats received either a cortical impact or sham injury and were then randomly assigned to 8 groups receiving continuous or early and delayed EE with either 1 or 2 weeks of exposure. Functional outcome was assessed with established motor (beam-balance/walk) and cognitive (Morris water maze) tests on postinjury days 1 to 5 and 14 to 18, respectively.
  
  
  RESULTS
  Motor ability was enhanced in the TBI groups that received early EE (ie, during testing) versus standard housing. In contrast, acquisition of spatial learning was facilitated in the groups receiving delayed EE (ie, during training).
  
  
  CONCLUSIONS
  These data support the conclusion from the previous study that EE-mediated functional improvement after TBI is contingent on task-specific neurobehavioral experience and extends those preliminary findings by demonstrating that the duration of enriched exposure is also important for functional recovery.
authors: Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA.
authors: Ashley M
authors: AM
authors: Matter
authors: Kaitlin A
authors: KA
authors: Folweiler
authors: Lauren M
authors: LM
authors: Curatolo
authors: Anthony E
authors: AE
authors: Kline
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001930:Brain Injuries / Q000503:physiopathology* / Q000534:rehabilitation*; D004195:Disease Models, Animal; D004780:Environment, Controlled; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology*; D013995:Time; D013997:Time Factors