Abstract
Traumatic brain injury (TBI) results from mechanical forces applied to the head. Ensuing cascades of complex pathophysiology transition the injury event into a disease process. The enduring constellation of emotional, somatic, and cognitive impairments degrade quality of life for the millions of TBI survivors suffering from long-term neurological symptoms. Rehabilitation strategies have reported mixed results, as most have not focused on specific symptomatology or explored cellular processes. The current experiments evaluated a novel cognitive rehabilitation paradigm for brain-injured and uninjured rats. The arena is a plastic floor with a cartesian grid of holes for plastic dowels to create new environments with the rearrangement of threaded pegs. Rats received either two weeks of Peg Forest rehabilitation (PFR) or open field exposure starting at 7 days post-injury; or one week starting at either day 7 or 14 post-injury; or served as caged controls. Cognitive performance was assessed on a battery of novel object tasks at 28 days post-injury. The results revealed that two weeks of PFR was required to prevent the onset of cognitive impairments, while one week of PFR was insufficient regardless of when rehabilitation was initiated after injury. Further assessment of the task showed that novel daily arrangements of the environment were required to impart the cognitive performance benefits, as exposure to a static arrangement of pegs for PFR each day did not improve cognitive performance. The results indicate that PFR prevents the onset of cognitive disorders following acquired a mild to moderate brain injury, and potentially other neurological conditions.