Significant increase in post-traumatic sleep is independent of the time of day of the injury.

Mice subjected to mild or moderate injury at 9:00 (A), following the dark/light transition showed significant increases in acute post-traumatic sleep compared to uninjured sham. A multivariate ANOVA and Bonferroni post-hoc analysis was used (mean ±SEM; sham n = 12; injured n = 17; F(1,25) = 15.95); *, p<0.05). Mice subjected to mild or moderate injury at 21:00 (B), following the light/dark transition also showed significant increases in acute post-traumatic sleep compared to sham. A multivariate ANOVA and Bonferroni post-hoc analysis was used (mean ±SEM; sham n = 5; injured n = 14; F(1,17) = 4.42; *, p<0.05). An increase in sleep is observed acutely following TBI and is observed over the course of the first 3 hours in injured mice compared to sham. After 3 hours, sleep began to normalize in the injured animals and became indistinguishable from sleep in the sham. Mean percent sleep of uninjured sham mice in the 9:00 group was significantly higher than the mean percent sleep of sham mice in the 21:00 group (F(1,15) = 6.303, p = 0.0240), as expected.