In effects of both treatment (F(3, 148.62) = 35.06, p < 0.001) and photoperiod (F(1, 135.42) = 5.438, p = 0.21). 5 mg/kg AM281 increased the overall power in the theta bandwidth during NREM sleep (t(118.00) = 5.01, p < 0.001) with specific pair-wise comparisons over the majority of the recording (ZT00-21: t(150.13) ! 2.86, p 0.014). Finally, analysis of NREM gamma found an overall interaction (F(24, 233.59) = 14.55, p < 0.001) with main effects of both treatment (F(3, 121.33) = 7.128, p < 0.001) and photoperiod (F(1, 127.916) = 93.21, p < 0.001), but there were no significant differences between AM281 and vehicle. The CB1 antagonist also affected EEG spectral content during REM (Fig 11F). For REM delta power, there was an overall interaction (F(24, 217.83) = 1.68, p = 0.028) with a main effect of treatment (F(3, 54.98) = 7.64, p < 0.001). 5.0 mg/kg AM281 increased delta power during REM sleep epochs across the day (t(40.91) = 2.82, p < 0.022), but this was mainly due to increased REM delta during the first 9 Hr (ZT00-09: t(76.78) ! 3.54, p 0.002). For REM theta power, there was a secondary interaction (treatment x photoperiod, F(3, 146.49) = 9.23, p < 0.001) with main effects of both treatment (F(3, 51.66) = 19.22, p < 0.001) and photoperiod (F(1, 219.58) = 18.05, p < 0.001). Overall, 5.0 mg/kg AM281 increased REM theta power (t(39.91) = 5.23, p < 0.001), particularly during the first 15 Hr of the recording (ZT00-15: t (85.58) ! 3.92, p 0.001). There was a treatment x photoperiod interaction for REM gamma power (F(3, 168.32) = 3.61, p = 0.015) with a main effect of photoperiod (F(1, 196.66) = 8.13, p = 0.005). Overall, REM gamma was augmented by the high dose of AM281 during the light photoperiod (t(51.71) = 3.12, p = 0.009), but there were no differences SART.S23506 at specific time points. Thus, blockade of CB1 receptors produces broadband changes in the EEG waveform that are particularly evident in lower frequencies irrespective of vigilance state.PLOS ONE | DOI:10.1371/journal.pone.0152473 March 31,26 /Endocannabinoid BLU-554 site Signaling Regulates Sleep StabilityFig 11. Blockade of CB1 Receptors Produces Broadband Changes in EEG Power Spectral Features. Results are from experiment where AM281 was administered at the onset of the LP. A–C, Average of power spectra for each photoperiod and for each vigilance state across different days of the experiment. Solid lines indicate mean of all subjects as a function of frequency, and shaded regions j.jebo.2013.04.005 surrounding lines denotes standard error of the mean. A, Power spectra from wake epochs. B, Power spectra from NREM epochs. C, Power spectra from REM epochs. D , Average power in specified bandwidths in each state for 3 Hr epochs over the day. Data from each vigilance state are color coded with wake in red (D), NREM in blue (E), and REM in green (F). Gray backgrounds indicate the DP. Asterisks (*) denote significant pair-wise comparisons between drug conditions and measures ��-Amatoxin manufacturer obtained during vehicle baseline. Symbols represent means EM across all subjects (N = 9) for each 3 Hr time bin. doi:10.1371/journal.pone.0152473.geCB Signaling is Not Necessary for Sleep Homeostasis but is Required for the Stability of Rebound SleepMeasures of EEG delta and theta power are frequently used as an index of sleep drive [44, 50, 51], and according to this interpretation, the large increase in NREM delta power following administration of AM281 may be indicative of augmented sleep homeostatic drive. Thus, we sought to test this possibilit.In effects of both treatment (F(3, 148.62) = 35.06, p < 0.001) and photoperiod (F(1, 135.42) = 5.438, p = 0.21). 5 mg/kg AM281 increased the overall power in the theta bandwidth during NREM sleep (t(118.00) = 5.01, p < 0.001) with specific pair-wise comparisons over the majority of the recording (ZT00-21: t(150.13) ! 2.86, p 0.014). Finally, analysis of NREM gamma found an overall interaction (F(24, 233.59) = 14.55, p < 0.001) with main effects of both treatment (F(3, 121.33) = 7.128, p < 0.001) and photoperiod (F(1, 127.916) = 93.21, p < 0.001), but there were no significant differences between AM281 and vehicle. The CB1 antagonist also affected EEG spectral content during REM (Fig 11F). For REM delta power, there was an overall interaction (F(24, 217.83) = 1.68, p = 0.028) with a main effect of treatment (F(3, 54.98) = 7.64, p < 0.001). 5.0 mg/kg AM281 increased delta power during REM sleep epochs across the day (t(40.91) = 2.82, p < 0.022), but this was mainly due to increased REM delta during the first 9 Hr (ZT00-09: t(76.78) ! 3.54, p 0.002). For REM theta power, there was a secondary interaction (treatment x photoperiod, F(3, 146.49) = 9.23, p < 0.001) with main effects of both treatment (F(3, 51.66) = 19.22, p < 0.001) and photoperiod (F(1, 219.58) = 18.05, p < 0.001). Overall, 5.0 mg/kg AM281 increased REM theta power (t(39.91) = 5.23, p < 0.001), particularly during the first 15 Hr of the recording (ZT00-15: t (85.58) ! 3.92, p 0.001). There was a treatment x photoperiod interaction for REM gamma power (F(3, 168.32) = 3.61, p = 0.015) with a main effect of photoperiod (F(1, 196.66) = 8.13, p = 0.005). Overall, REM gamma was augmented by the high dose of AM281 during the light photoperiod (t(51.71) = 3.12, p = 0.009), but there were no differences SART.S23506 at specific time points. Thus, blockade of CB1 receptors produces broadband changes in the EEG waveform that are particularly evident in lower frequencies irrespective of vigilance state.PLOS ONE | DOI:10.1371/journal.pone.0152473 March 31,26 /Endocannabinoid Signaling Regulates Sleep StabilityFig 11. Blockade of CB1 Receptors Produces Broadband Changes in EEG Power Spectral Features. Results are from experiment where AM281 was administered at the onset of the LP. A–C, Average of power spectra for each photoperiod and for each vigilance state across different days of the experiment. Solid lines indicate mean of all subjects as a function of frequency, and shaded regions j.jebo.2013.04.005 surrounding lines denotes standard error of the mean. A, Power spectra from wake epochs. B, Power spectra from NREM epochs. C, Power spectra from REM epochs. D , Average power in specified bandwidths in each state for 3 Hr epochs over the day. Data from each vigilance state are color coded with wake in red (D), NREM in blue (E), and REM in green (F). Gray backgrounds indicate the DP. Asterisks (*) denote significant pair-wise comparisons between drug conditions and measures obtained during vehicle baseline. Symbols represent means EM across all subjects (N = 9) for each 3 Hr time bin. doi:10.1371/journal.pone.0152473.geCB Signaling is Not Necessary for Sleep Homeostasis but is Required for the Stability of Rebound SleepMeasures of EEG delta and theta power are frequently used as an index of sleep drive [44, 50, 51], and according to this interpretation, the large increase in NREM delta power following administration of AM281 may be indicative of augmented sleep homeostatic drive. Thus, we sought to test this possibilit.