A single dose of flumazenil results in near baseline sleep characteristics following isoflurane anesthesia and mitigates an increase in REM sleep. For both saline (SAL – blue) and flumazenil (FLZ – orange) treated animals, sleep characteristics were evaluated for a 24-hour period before (baseline – BL) and after (post-anesthesia day 1 – PAD1) isoflurane anesthesia. A, Total sleep times. Saline-treated animals were asleep for significantly longer following anesthesia compared to baseline. There were no significant differences in baseline sleep times between the two groups (p=0.383, Mann-Whitney U test). Connected pairs of dots represent corresponding sleep times for individual animals. * p=0.008, Wilcoxon signed rank; strong effect. B, C, Amount of time in NREM (B) and REM (C) sleep. Connected pairs of dots represent time spent in NREM sleep for saline-treated (blue) and flumazenil-treated (orange) animals. Saline-treated animals spent significantly more time in both NREM and REM sleep following anesthesia compared to baseline. BL – darker shaded dots; PAD1 – lighter shaded dots. n = 8 animals per group; * Wilcoxon signed rank; strong effect for both REM (p = 0.008) and NREM (p=0.008) sleep.