Poster abstracts
Poster number 79 submitted by Christopher Cotter
Sleep Fragmentation Compromises Sleep Recovery Patterns Following Traumatic Brain Injury
Christopher Cotter (Department Of Neuroscience, IBMR), Zoe Tapp (IBMR), Cindy Ren (IBMR), Sam Houle (Department Of Neuroscience, IBMR), John Sheridan (Department Of Neuroscience, IBMR), Jonathan Godbout (Department Of Neuroscience, IBMR)
Abstract:
Sleep disturbances affect 30-70% of survivors following traumatic brain injury (TBI). While mortality has decreased from TBI exposure, more individuals are living with post injury consequences such as sleep dysregulation. Sleep expression, or the duration and frequency of wakefulness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep is a complex homeostatic process that is influenced by biological and environmental factors. One common factor that has a potential to impact both sleep and TBI recovery is stress. We hypothesize that environmental sleep fragmentation (SF) is sufficient to compromise the regulation of sleep recovery following TBI. To investigate this, equal numbers of male and female mice received sham injury or lateral fluid percussion TBI. All mice were implanted with a wireless telemetry sensor to monitor wakefulness, NREM, and REM sleep 1-30 days post-injury (DPI). Half of the mice in each group were exposed to control housing and the other half were exposed to mechanical SF every 2 minutes ZT0-ZT4 1-28 DPI. Following the SF period, all mice were undisturbed for the remaining light and dark phase (ZT12-ZT23). This model of SF caused a selective loss of REM sleep bouts greater than 60s and NREM sleep bouts greater than 120s 1-30 DPI. TBI increased REM sleep 1-7 DPI. TBI SF mice displayed an increase in the frequency of short REM bouts but no changes in the length of these bouts compared to sham SF and TBI controls ZT5-ZT12 1-7 DPI. These differences resolved 14-28 DPI. Robust between group differences in NREM sleep were detected in the dark phase 7 and 21 DPI. Careful assessment of bout differences in NREM sleep and wake are ongoing. These data underscore the influence of environmental factors in recovery of sleep wake behavior after TBI.
Keywords: Sleep , TBI, Recovery