EM and REM epochs. Thus, the attenuation of gamma oscillations, particularly

EM and REM epochs. Thus, the attenuation of gamma oscillations, particularly during sleep, seems to be a consistent effect of increased eCB signaling.Blockade of CB1 Fragments NREM Sleep and Substantially Alters Power Spectral Features of the EEGSleep Measurements. To determine if eCB/CB1 signaling is necessary for the normal circadian fluctuation in NREM and REM sleep, we performed experiments with the full, selective CB1 antagonist/inverse agonist AM281. LY2510924 web following AM281 administration, there was a substantial fragmentation of NREM sleep and a loss of REM, particularly when this drug was administered prior to the LP (Fig 9). Again, given that eCBs exhibit a circadian fluctuation that differs by brain region, it was not easy to predict a priori an optimal time to administer the drug, so two separate experiments were performed where AM281 was given at opposite points in the circadian phase, immediately before either the LP or DP. In both experiments, two doses of AM281, 0.5 mg/kg (low) and 5.0 mg/kg (high), were administered sequentially on consecutive days following a baseline day when vehicle was given (Fig 10A). When AM281 was administered prior to the DP (Fig 10B, top row), NREM sleep time was affected by an overall interaction (treatment x time of day within photoperiod, F(18, 198.82) = 10.27, p < 0.001) with a main effect of photoperiod (F(1, 169.19) = 836.77, p < 0.001). Only the high dose of AM281 produced effects on NREM sleep time, and the magnitude of these effects was small. Specifically, there was an increase in NREM sleep time during the first quarter of the DP (t(261.07) = 2.93, p = 0.007) and a decrease during the second quarter (t(261.09) = -3.20, p = 0.003). The 1471-2474-14-48 effect on NREM bout duration was more pronounced with a significant overall interaction (treatment x time of day within photoperiod, F(18, 201.36) = 7.20, p < 0.001) and main effects of both treatment (F(2, 69.38) = 3.86, p = 0.026) and photoperiod (F(1, 163.20) = 86.17, p < 0.001). Following administration of high dose AM281, there was an overall reduction in NREM bout duration (t(72.79) = -2.64, p = 0.020) with a significant reduction during the second quarter of the DP (ZT15-18: t(205.68) = -3.02, p = 0.006). The number of NREM bouts was also affected by an overall interaction (F(18, 204.63) = 3.46, p < 0.001) with main effects of both treatment (F(2, 61.58) = 3.30, p = 0.043) and photoperiod (F(1, 173.11) = 25.90, p < 0.001). However, this result was largely driven by an increasedPLOS ONE | DOI:10.1371/journal.pone.0152473 March 31,22 /Endocannabinoid Signaling Regulates Sleep StabilityFig 9. Example EEG/EMG Traces on Different Time Scales Following Vehicle or AM281 Administration. EEG and EMG traces are from the same subject at the same stage of the circadian cycle after administration of either vehicle (A, A', and left column of C) or 5 mg/kg AM281 (B, B', and right column of C). Data are from experiment with AM281 administration before the LP. Panels A and B show a 2 Hr 15 min window from ZT 00:15?2:30, roughly 15?0 min after drug administration, coinciding with peak effects observed on sleep. Panels A' and B' show a 15 min long segment expanded from the region in A and B highlighted by the dashed orange box. Panel C shows representative 18 sec long data segments corresponding to 1471-2474-14-48 effect on NREM bout duration was more pronounced with a significant overall interaction (treatment x time of day within photoperiod, F(18, 201.36) = 7.20, p < 0.001) and main effects of both treatment (F(2, 69.38) = 3.86, p = 0.026) and photoperiod (F(1, 163.20) = 86.17, p < 0.001). Following administration of high dose AM281, there was an overall reduction in NREM bout duration (t(72.79) = -2.64, p = 0.020) with a significant reduction during the second quarter of the DP (ZT15-18: t(205.68) = -3.02, p = 0.006). The number of NREM bouts was also affected by an overall interaction (F(18, 204.63) = 3.46, p < 0.001) with main effects of both treatment (F(2, 61.58) = 3.30, p = 0.043) and photoperiod (F(1, 173.11) = 25.90, p < 0.001). However, this result was largely driven by an increasedPLOS ONE | DOI:10.1371/journal.pone.0152473 March 31,22 /Endocannabinoid Signaling Regulates Sleep StabilityFig 9. Example EEG/EMG Traces on Different Time Scales Following Vehicle or AM281 Administration. EEG and EMG traces are from the same subject at the same stage of the circadian cycle after administration of either vehicle (A, A', and left column of C) or 5 mg/kg AM281 (B, B', and right column of C). Data are from experiment with AM281 administration before the LP. Panels A and B show a 2 Hr 15 min window from ZT 00:15?2:30, roughly 15?0 min after drug administration, coinciding with peak effects observed on sleep. Panels A' and B' show a 15 min long segment expanded from the region in A and B highlighted by the dashed orange box. Panel C shows representative 18 sec long data segments corresponding to SART.S23503 NREM and wake obtained following vehicle and AM281 administration. These data segments were taken from the segments shown in A and B. The color-coded hypnogram shown at the botto.