During the LP (t(54.99) = -4.49, p < 0.001) and increased by low dose AM281 during the DP (t(54.65) = 2.44, p = 0.036). At the high dose, AM281 reduced the number of REM bouts across most jasp.12117 of the LP (ZT00-06 09?2: t(162.69) -2.67, p = 0.002), while low dose AM281 decreased the number of REM bouts during the second quarter of the LP (ZT03-06: t (162.62) = -3.30, p = 0.002) and increased REM bouts during the third quarter of the DP (ZT1821: t(157.68) = 2.51, p = 0.026). Thus, 6-Methoxybaicalein site blockade of CB1 signaling fragments NREM and decreases REM sleep, suggesting that this receptor is necessary for NREM stability. EEG Power AZD0156 site spectral Measurements. Given that blockade of endocannabinoid signaling through CB1 fragments NREM sleep, we hypothesized that power spectral features associated with sleep might be disrupted after acute administration of CB1 antagonists. Administration of AM281 before the LP had large effects on power spectral features of the EEG across vigilancePLOS ONE | DOI:10.1371/journal.pone.0152473 March 31,25 /Endocannabinoid Signaling Regulates Sleep Stabilitystates, but the nature of these effects was different across states (Fig 11A?1C). Notably, the power of low frequencies (< 8 Hz) was consistently increased, and high frequencies (gamma, > 30 Hz) were much less affected by CB1 blockade. These effects lasted for most of the day, and a similar time course was observed in experiments where AM281 was administered before the DP (S8 Fig), suggesting that this effect is not modulated by circadian processes. As for we did for CP47, AM3506, and JZL184 we quantified power spectral bandwidths (delta, theta, and gamma) in 3 Hr time bins over the entire recording (Fig 11D?1F). During wake epochs (Fig 11D) there was a significant interaction (treatment x time of day within photoperiod, F(24, 229.63) = 5.26, p < 0.001) with main effects of both treatment (F(3, 73.99) = 42.19, p < 0.001) and photoperiod (F(1, 154.27) = 127.39, p < 0.001) for delta power. Only the 5.0 mg/kg dose significantly elevated wake delta relative to vehicle (t(53.52) = 7.21, p < 0.001), and comparisons at individual time points found that this effect lasted for 18 Hr after drug administration (ZT00-18: t(83.70) > 3.13, p 0.007). Wake theta power was also modulated by a significant interaction (F(24, 228.72) = 3.23, p < 0.001) and main effects of both treatment (F(3, 69.952) = 20.74, p < 0.001) and photoperiod (F(1, 157.78) = 13.20, p < 0.001). Again, only the high dose j.jebo.2013.04.005 of AM281 significantly elevated theta power over the circadian cycle (t (50.532) = 5.35, p < 0.001), and theta power was increased over the first 18 Hr of the recording period (ZT00-18: t(80.45) > 3.97, p < 0.001). Analysis of wake gamma power also found an overall interaction (F(24, 227.65) = 8.013, p < 0.001) with a main effect of photoperiod (F(1, 143.48) = 89.70, p < 0.001), but no pair-wise comparisons between treatment conditions and the vehicle baseline reached significance. AM281 also altered EEG power spectra during NREM epochs (Fig 11E). For NREM delta power, there was a significant overall interaction (F(24, 229.40) = 9.84, p < 0.001) with a main effect of treatment (F(3, 80.45) = 28.89, p < 0.001). 5 mg/kg AM281 produced an overall increase in NREM delta power (t(58.23) = 5.54, p < 0.001) with pair-wise differences noted across the vast majority of the recording (ZT00-21: t(88.09) ! 2.53, p 0.039). There was also an overall interaction for NREM theta power (F(24, 235.54) = 6.31, p < 0.001) with ma.During the LP (t(54.99) = -4.49, p < 0.001) and increased by low dose AM281 during the DP (t(54.65) = 2.44, p = 0.036). At the high dose, AM281 reduced the number of REM bouts across most jasp.12117 of the LP (ZT00-06 09?2: t(162.69) -2.67, p = 0.002), while low dose AM281 decreased the number of REM bouts during the second quarter of the LP (ZT03-06: t (162.62) = -3.30, p = 0.002) and increased REM bouts during the third quarter of the DP (ZT1821: t(157.68) = 2.51, p = 0.026). Thus, blockade of CB1 signaling fragments NREM and decreases REM sleep, suggesting that this receptor is necessary for NREM stability. EEG Power Spectral Measurements. Given that blockade of endocannabinoid signaling through CB1 fragments NREM sleep, we hypothesized that power spectral features associated with sleep might be disrupted after acute administration of CB1 antagonists. Administration of AM281 before the LP had large effects on power spectral features of the EEG across vigilancePLOS ONE | DOI:10.1371/journal.pone.0152473 March 31,25 /Endocannabinoid Signaling Regulates Sleep Stabilitystates, but the nature of these effects was different across states (Fig 11A?1C). Notably, the power of low frequencies (< 8 Hz) was consistently increased, and high frequencies (gamma, > 30 Hz) were much less affected by CB1 blockade. These effects lasted for most of the day, and a similar time course was observed in experiments where AM281 was administered before the DP (S8 Fig), suggesting that this effect is not modulated by circadian processes. As for we did for CP47, AM3506, and JZL184 we quantified power spectral bandwidths (delta, theta, and gamma) in 3 Hr time bins over the entire recording (Fig 11D?1F). During wake epochs (Fig 11D) there was a significant interaction (treatment x time of day within photoperiod, F(24, 229.63) = 5.26, p < 0.001) with main effects of both treatment (F(3, 73.99) = 42.19, p < 0.001) and photoperiod (F(1, 154.27) = 127.39, p < 0.001) for delta power. Only the 5.0 mg/kg dose significantly elevated wake delta relative to vehicle (t(53.52) = 7.21, p < 0.001), and comparisons at individual time points found that this effect lasted for 18 Hr after drug administration (ZT00-18: t(83.70) > 3.13, p 0.007). Wake theta power was also modulated by a significant interaction (F(24, 228.72) = 3.23, p < 0.001) and main effects of both treatment (F(3, 69.952) = 20.74, p < 0.001) and photoperiod (F(1, 157.78) = 13.20, p < 0.001). Again, only the high dose j.jebo.2013.04.005 of AM281 significantly elevated theta power over the circadian cycle (t (50.532) = 5.35, p < 0.001), and theta power was increased over the first 18 Hr of the recording period (ZT00-18: t(80.45) > 3.97, p < 0.001). Analysis of wake gamma power also found an overall interaction (F(24, 227.65) = 8.013, p < 0.001) with a main effect of photoperiod (F(1, 143.48) = 89.70, p < 0.001), but no pair-wise comparisons between treatment conditions and the vehicle baseline reached significance. AM281 also altered EEG power spectra during NREM epochs (Fig 11E). For NREM delta power, there was a significant overall interaction (F(24, 229.40) = 9.84, p < 0.001) with a main effect of treatment (F(3, 80.45) = 28.89, p < 0.001). 5 mg/kg AM281 produced an overall increase in NREM delta power (t(58.23) = 5.54, p < 0.001) with pair-wise differences noted across the vast majority of the recording (ZT00-21: t(88.09) ! 2.53, p 0.039). There was also an overall interaction for NREM theta power (F(24, 235.54) = 6.31, p < 0.001) with ma.