Poster abstracts
Poster number 72 submitted by Christopher Cotter
Sleep Fragmentation Compromises Sleep Recovery Patterns Following Traumatic Brain Injury
Christopher Cotter (Department of Neuroscience, Institute for Behavioral Medicine Research), Zoe Tapp (Institute for Behavioral Medicine Research), Sam Houle (Department of Neuroscience, Institute for Behavioral Medicine Research), John Sheridan (Division of Biosciences, College of Dentistry, ), Jonathan Godbout (Department of Neuroscience, Institute for Behavioral Medicine Research), Ahsley Ingiosi (1.Department of Neuroscience)
Abstract:
Homeostatic control of sleep, or the expression of non-rapid eye movement sleep (NREMs) and rapid eye movement sleep (REMs), is critical for recovery after traumatic brain injury (TBI). TBI survivors are susceptible to sleep disturbances in response to stress, thus environmental sleep fragmentation (SF) is a relevant approach to study stress-induced sleep disturbances following TBI. We hypothesize that SF exacerbates TBI-induced sleep deficits and worsens sleep quality. Mice received a moderate lateral fluid percussion TBI or sham injury. Mice were implanted with wireless telemetry sensors to monitor sleep expression and activity. Mice were then either left undisturbed or exposed to 4 hours of daily SF (ZT0-3) for 30 days post-injury (DPI). SF after TBI presented activity deficits one week earlier compared to TBI control mice. SF minimally impacted NREMs expression but chronically ablated REMs. Sham SF mice compensated for decreased REMs expression after the SF period (ZT4-11) while TBI and TBI SF mice did not. Sleep quality, as defined as sleep bout number and length, was chronically disturbed by TBI SF but not TBI alone. Using spectral analysis, we observed decreased REM beta (13-20Hz; memory/arousal) power and decreased gamma (20-30Hz; attention/memory processing) power due to TBI and SF. Additionally, we observed decreased REM theta (4.0-8.0Hz; memory consolidation) power due to SF and decreased NREM delta (0.1-4Hz; sleep need) power in TBI and TBI SF mice. These data highlight the vulnerability in REM sleep following TBI and exaggerated consequences associated with TBI in the presence of sleep fragmentation.
Keywords: Sleep, Traumatic Brain Injury , Fragmentation