A Rat Model of Sleep Deprivation Prior to Traumatic Brain Injury

Traumatic Brain Injury (TBI) has been called the "signature injury" of U.S. soldiers in Iraq and Afghanistan. Soldiers undergo a variety of stressors during their tours of duty that could complicate recovery from TBI, one of which is sleep deprivation (SD). In this study, we sought to create a rat model exploring the effects of prior REM sleep deprivation (RSD) on recovery from TBI-induced sensorimotor and cognitive deficits. Rats were deprived of REM sleep before they underwent a controlled cortical impact (CCI) to mimic a TBI. Forelimb sensorimotor function, hindlimb motor function, forelimb motor function, and spatial learning were assessed using the Bilateral Tactile Stimulation (BTS) test, Ledged Tapered Beam (LTB) test, Limb-use Asymmetry Cylinder (LAC) test, and Morris Water Maze (MWM) respectively. Our hypothesis was that RSD would impede CCI recovery compared to controls that underwent CCI without prior RSD. However, rats undergoing RSD prior to CCI exhibited less impairment during the BTS and LTB tests than controls that underwent CCI without prior RSD. Additionally, control rats that underwent the condition where they spent 24 hours in the RSD chamber without RSD prior to CCI performed worse than all the other groups during the MWM task. No group differences were found in the LAC test. These findings led us to reject our hypothesis and theorize that RSD had a neuroprotective effect against TBI-related damage. Furthermore, we concluded that stress prior to TBI worsened recovery, and that SD protected against this effect