Exposure to environmental complexity promotes recovery of cognitive function after traumatic brain injury

Robert J. Hamm, Meredith D. Temple, Dianne M. O'Dell, Brian R. Pike, Bruce G Lyeth

Research output: Contribution to journalArticlepeer-review

121 Scopus citations


This study was designed to determine whether exposure to a complex environment after traumatic brain injury (TBI) would promote the recovery of cognitive function. Rats were injured at a moderate level of fluid percussion injury (2.1 atm) or were prepared for injury but were not injured (sham injury). Immediately after the injury or sham injury, the injured/complex (n = 8) and the sham/complex (n = 7) groups were placed into a complex environment. The complex environment was a 89 x 89-cm enclosure with different types of bedding and objects that provided motor, olfactory, tactile, and visual stimulation. The injured/standard (n = 8) and the sham/standard (n = 8) groups were returned to the animal vivarium where they were housed individually in standard wire mesh cages (24 x 20 x 18 cm). On days 11-15 (postinjury), performance in the Morris water maze was assessed. Analysis of the latency to reach the goal platform indicated that injured animals recuperating in the complex environment performed significantly better than injured animals recovering in the standard environment (p < 0.01). In fact, injured animals in the complex environment performed as well as both sham-injured groups. The improved performance of injured rats recovering in the enriched environment occurred in the absence of environmentally induced alterations in brain weight. These results indicate that exposure to environmental complexity enhances recovery of cognitive function after TBI.

Original languageEnglish (US)
Pages (from-to)41-47
Number of pages7
JournalJournal of Neurotrauma
Issue number1
StatePublished - Jan 1996
Externally publishedYes


  • environments
  • memory
  • Morris water maze
  • recovery
  • traumatic brain injury

ASJC Scopus subject areas

  • Clinical Neurology
  • Neuroscience(all)


Dive into the research topics of 'Exposure to environmental complexity promotes recovery of cognitive function after traumatic brain injury'. Together they form a unique fingerprint.

Cite this