Sleep-wake architecture, duration, and fragmentation in male and female mice following midline fluid percussion injury

STUDY PURPOSE: Traumatic brain injury (TBI) causes sleep disturbances which can delay recovery and lead to long-term neurological morbidities in survivors. Clinical data indicate that TBI alters acute sleep following mild and moderate brain injury; however, limited preclinical research has evaluated injury severity as a parameter when investigating post-traumatic sleep after TBI. We hypothesized that sleep duration would increase after TBI regardless of the injury severity. However, we anticipated that the severity of the injury would specifically influence sleep quality, with more severe injuries leading to greater sleep fragmentation. DATA COLLECTED: We exposed male and female adult mice (C57BL/6J; RRID:IMSR_JAX:000664) to sham, mild, moderate midline fluid percussion injury (mFPI). The group sizes were: mild TBI female n = 15, moderate TBI female n = 15, sham female n = 14, mild TBI male n = 17, moderate TBI male n = 17, sham male n = 16. Physiological parameters were recorded using non-invasive piezoelectric cages to determine non-rapid eye movement (NREM) sleep, rapid eye movement (REM)-like sleep, and wakefulness (WAKE) for two days following TBI. Data collected were binned at each hour using a rolling average of the percentage of recording time spent in sleep. Data were also binned by length of individual bout to calculate the hourly mean bout length (duration in seconds). To be considered a bout, a minimum of two consecutive epochs had to be scored as sleep (or wake). Total minutes slept within each experimental period (e.g., day 1) was also calculated. We also determined the sleep-wake transitions on both hourly and daily intervals. DATA USAGE NOTES: