Daytime Recovery Research Articles

Effects of workday characteristics and job demands on recovery from work among Finnish home care nurses: a multi-source cross-sectional study

ObjectiveAgeing populations and poor care workforce availability are causing increasing job demands for home care nurses across Europe. While recovery from work helps sustain work ability and wellbeing, past research has relied mainly on self-reported measures of health, stressors, and recovery. This study aims to examine how objective and subjective job demands are associated with measured day-time recovery among home care nurses.MethodsHeart rate variability recording was conducted for 95 Finnish home care nurses. The study participants documented their work tasks throughout the workday and filled a wellbeing questionnaire. The amount of care time, breaktime, number of different weekly clients, and their care needs were obtained from the survey. The associations between job demands and measured day-time recovery were analysed using multivariate linear regression.ResultsThe amount of day-time recovery was on average 75 min. The number of different clients during the workday (e.g., care continuity) and higher care needs of the clients were associated with lower day-time recovery. Additionally, something slightly disrupting the course of the workday was associated with increased recovery.ConclusionsOur findings indicate that reducing especially the objective job demands (workday characteristics) can contribute to better day-time recovery among home care nurses. To help sustain work ability and improve wellbeing, day-time recovery can be promoted with better work scheduling that supports care continuity and ensures sufficient care resources and support for nurses with many clients or clients with high care needs.

Obstructive sleep apnea in airline pilots during daytime sleep following overnight flights.

To identify the vulnerability of recovery sleep, this study investigated the occurrence of obstructive sleep apnea during daytime sleep following overnight flights in healthy airline pilots. We conducted daytime polysomnography following a long-haul night-time flight in 103 pilots. The following variables were assessed: apnea-hypopnea index, respiratory disturbance index and oxygen desaturation index. Moderate-to-severe obstructive sleep apnea was defined as an apnea-hypopnea index ≥15. Seventy-three pilots (70.9%) with no known history of obstructive sleep apnea presented with moderate-to-severe obstructive sleep apnea. Pilots showed high mean apnea-hypopnea, respiratory disturbance and oxygen desaturation indices. The body mass index, Berlin questionnaire score and cumulative flight time contributed to these indices, with both body mass index and cumulative flight time remaining significant at an apnea-hypopnea index ≥15. We found that pilots are vulnerable to obstructive sleep apnea during daytime sleep after night-time flights, which may deteriorate their health, increase fatigue and impair overall flight safety. Further research is needed to ensure flight safety, as daytime recovery sleep is unavoidable for night-time flight pilots. The pilots' normal and recovery sleep patterns should both be studied to develop an effective sleep management protocol.

AANAT1 functions in astrocytes to regulate sleep homeostasis.

How the brain controls the need and acquisition of recovery sleep after prolonged wakefulness is an important issue in sleep research. The monoamines serotonin and dopamine are key regulators of sleep in mammals and in Drosophila. We found that the enzyme arylalkylamine N-acetyltransferase 1 (AANAT1) is expressed by Drosophila astrocytes and specific subsets of neurons in the adult brain. AANAT1 acetylates monoamines and inactivates them, and we found that AANAT1 limited the accumulation of serotonin and dopamine in the brain upon sleep deprivation (SD). Loss of AANAT1 from astrocytes, but not from neurons, caused flies to increase their daytime recovery sleep following overnight SD. Together, these findings demonstrate a crucial role for AANAT1 and astrocytes in the regulation of monoamine bioavailability and homeostatic sleep.

Caffeine has minimal effects on daytime recovery sleep following severe sleep deprivation

Caffeine has been shown to minimise the effects of sleep loss on performance and alertness. However, caffeine may also have negative repercussions for recovery sleep, particularly during the daytime. The current study investigated the impact of high caffeine consumption on daytime recovery sleep following 50 h wakefulness. Twenty-four healthy participants were randomly assigned to either a caffeine (n = 12, aged 22.5 ± 3.3 years) or placebo condition (n = 12, aged 22.5 ± 2.5 years). All participants were scheduled to one baseline sleep (22:00–08:00 h) and two nights (50 h) of wakefulness followed by a daytime recovery sleep (10:00–19:00 h). Each night at 01:00, 03:00, 05:00 and 07:00 h during the wake period participants were given 200 mg of caffeine or placebo gum. Caffeine reduced the amount of SWS within the first NREM–REM sleep cycles compared to placebo. However, there were no differences between the caffeine and placebo conditions with relation to the overall amount of SWS, REM sleep, stage 2 sleep, and sleep initiation and consolidation during the recovery sleep. Results suggest that caffeine can be used as a fatigue countermeasure in industries where work hours extend to 50 h without significantly disrupting recovery sleep, even during the daytime. Results may also have implications for workers working extended shifts who use caffeine to help reduce fatigue during the commute home.

Do night naps impact driving performance and daytime recovery sleep?

Short, nighttime naps are used as a fatigue countermeasure in night shift work, and may offer protective benefits on the morning commute. However, there is a concern that nighttime napping may impact upon the quality of daytime sleep. The aim of the current project was to investigate the influence of short nighttime naps (<30min) on simulated driving performance and subsequent daytime recovery sleep. Thirty-one healthy subjects (aged 21–35 y; 18 females) participated in a 3-day laboratory study. After a 9-h baseline sleep opportunity (22:00h–07:00h), subjects were kept awake the following night with random assignment to: a 10-min nap ending at 04:00h plus a 10-min nap at 07:00h; a 30-min nap ending at 04:00h; or a no-nap control. A 40-min driving simulator task was administered at 07:00h and 18:30h post-recovery sleep. All conditions had a 6-h daytime recovery sleep opportunity (10:00h–16:00h) the next day. All sleep periods were recorded polysomnographically. Compared to control, the napping conditions did not significantly impact upon simulated driving lane variability, percentage of time in a safe zone, or time to first crash on morning or evening drives (p>0.05). Short nighttime naps did not significantly affect daytime recovery total sleep time (p>0.05). Slow wave sleep (SWS) obtained during the 30-min nighttime nap resulted in a significant reduction in SWS during subsequent daytime recovery sleep (p<0.05), such that the total amount of SWS in 24-h was preserved. Therefore, short naps did not protect against performance decrements during a simulated morning commute, but they also did not adversely affect daytime recovery sleep following a night shift. Further investigation is needed to examine the optimal timing, length or combination of naps for reducing performance decrements on the morning commute, whilst still preserving daytime sleep quality.

Age-related changes in sleep spindles characteristics during daytime recovery following a 25-hour sleep deprivation.

Objectives: The mechanisms underlying sleep spindles (~11–15 Hz; >0.5 s) help to protect sleep. With age, it becomes increasingly difficult to maintain sleep at a challenging time (e.g., daytime), even after sleep loss. This study compared spindle characteristics during daytime recovery and nocturnal sleep in young and middle-aged adults. In addition, we explored whether spindles characteristics in baseline nocturnal sleep were associated with the ability to maintain sleep during daytime recovery periods in both age groups.Methods: Twenty-nine young (15 women and 14 men; 27.3 y ± 5.0) and 31 middle-aged (19 women and 13 men; 51.6 y ± 5.1) healthy subjects participated in a baseline nocturnal sleep and a daytime recovery sleep after 25 hours of sleep deprivation. Spindles were detected on artifact-free Non-rapid eye movement (NREM) sleep epochs. Spindle density (nb/min), amplitude (μV), frequency (Hz), and duration (s) were analyzed on parasagittal (linked-ears) derivations.Results: In young subjects, spindle frequency increased during daytime recovery sleep as compared to baseline nocturnal sleep in all derivations, whereas middle-aged subjects showed spindle frequency enhancement only in the prefrontal derivation. No other significant interaction between age group and sleep condition was observed. Spindle density for all derivations and centro-occipital spindle amplitude decreased whereas prefrontal spindle amplitude increased from baseline to daytime recovery sleep in both age groups. Finally, no significant correlation was found between spindle characteristics during baseline nocturnal sleep and the marked reduction in sleep efficiency during daytime recovery sleep in both young and middle-aged subjects.Conclusion: These results suggest that the interaction between homeostatic and circadian pressure modulates spindle frequency differently in aging. Spindle characteristics do not seem to be linked with the ability to maintain daytime recovery sleep.

Effects of Caffeine on Skin and Core Temperatures, Alertness, and Recovery Sleep During Circadian Misalignment

Caffeine promotes wakefulness during night shift work, although it also disturbs subsequent daytime sleep. Increased alertness by caffeine is associated with a higher core body temperature (CBT). A lower CBT and a narrow distal-to-proximal skin temperature gradient (DPG) have been reported to be associated with improved sleep, yet whether caffeine influences the DPG is unknown. We tested the hypothesis that the use caffeine during nighttime total sleep deprivation would reduce the DPG, increase CBT and alertness, and disturb subsequent daytime recovery sleep. We also expected that a greater widening of the DPG prior to sleep would be associated with a greater degree of sleep disturbance. Thirty healthy adults (9 females) aged 21.6 ± 3.5 years participated in a double-blind, 28-h modified constant routine protocol. At 23 h of wakefulness, participants in the treatment condition (n = 10) were given 2.9 mg/kg caffeine, equivalent to ~200 mg (or 2 espressos) for a 70-kg adult, 5 h before a daytime recovery sleep episode. Throughout the protocol, core and skin body temperatures, DPG, sleep architecture, and subjective alertness and mood were measured. Prior to sleep, caffeine significantly widened the DPG and increased CBT, alertness, and clear-headedness (p < 0.05). Caffeine also disturbed daytime recovery sleep (p < 0.05). Increased CBT and a wider DPG prior to sleep were associated with a longer latency to sleep, and a wider DPG was associated with disturbed recovery sleep (i.e., increased wakefulness after sleep onset, increased stage 1 sleep, decreased sleep efficiency, and decreased slow wave sleep) (p < 0.05). A widening of the DPG following nighttime caffeine may represent a component of the integrated physiological response by which caffeine improves alertness and disturbs subsequent daytime recovery sleep. Furthermore, our findings highlight that sleep disturbances associated with caffeine consumed near the circadian trough of alertness are still present when daytime recovery sleep occurs 5 h or approximately 1 half-life later.

1265 POSTOPERATIVE ANATOMIC MEASUREMENTS WITH DYNAMIC MAGNETIC RESONANCE IMAGING: ASSOCIATION WITH URINARY CONTINENCE IN ORTHOTOPIC ILEAL NEOBLADDER AFTER RADICAL CYSTOPROSTATECTOMY FOR BLADDER CANCER

You have accessJournal of UrologyUrinary Diversion: Bladder Reconstruction, Augmentation, Substitution, Diversion (I)1 Apr 20131265 POSTOPERATIVE ANATOMIC MEASUREMENTS WITH DYNAMIC MAGNETIC RESONANCE IMAGING: ASSOCIATION WITH URINARY CONTINENCE IN ORTHOTOPIC ILEAL NEOBLADDER AFTER RADICAL CYSTOPROSTATECTOMY FOR BLADDER CANCER Jonathan Lopater, Antoine Scherrer, Servane Gey, Vincent Delmas, Yann Neuzillet, and Thierry Lebret Jonathan LopaterJonathan Lopater Suresnes, France More articles by this author , Antoine ScherrerAntoine Scherrer Suresnes, France More articles by this author , Servane GeyServane Gey Paris, France More articles by this author , Vincent DelmasVincent Delmas Paris, France More articles by this author , Yann NeuzilletYann Neuzillet Suresnes, France More articles by this author , and Thierry LebretThierry Lebret Suresnes, France More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.2619AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The objective of this study is to use dynamic magnetic resonance (MR) imaging to evaluate the roles of post-operative anatomic measurements in the recovery of urinary continence in orthotopic ileal neobladder after radical cystoprostatectomy for bladder cancer. METHODS Five case patients requiring clean intermittent self-catheterization (CISC), and thirty eight control patients who received a dynamic MR imaging with an orthotopic ileal neobladder after radical cystoprostatectomy for bladder cancer were evaluated in a prospective study at a single institution. Day-time and noctunal urinary continence was categorized as mode according to CISC requirement, perfect and not perfect continence, as incontinence severity according to pad count and as time to continence. Dynamic MR imaging anatomic measurements of pelvic bone and soft tissue were performed. Multivariate age-adjusted polytomus and ordinal logistic regressions after univariate mean and repartition comparison were performed to assess variables associated with urinary continence mode and incontinence severity. Univariate and multivariate age-adjusted cox regressions were performed to assess variables with time to continence recovery. RESULTS Day-time continence of control patients was perfect in 73.7% and satisfying in 94.7%. Univariate analyses selected 3 variables, but only levator ani thickness at the pouch-urethral anastomosis level predicted day-time urinary continence mode (relative risk ratio [RRR] = 2.14 per mm, perfect against not perfect, 95% CI [1.16, 3.97], p = 0.015), incontinence severity (Ordinal odds ratio = 2.08 per mm, 95% CI [1.27, 3.93], p = 0.007) and time to day-time recovery (Hazard ratio [HR]= 0.82 per mm, 95% CI [0.68, 1.00], p = 0.046). Levator ani muscle at the level of the urethra had a teardrop coronal shape, thicker at the bottom than at the top. Also, levator ani thickness at the pouch-urethral anastomosis level represented postoperative lack of membranous urethral support. CONCLUSIONS Data suggest that lack of membranous urethral support impacts on daytime urinary continence recovery of orthotopic ileoplasty after cystoprostatectomy for bladder cancer. Prognostic value on urinary continence recovery of post-operative peri-sphincteric structures establishes a pathophysiological role to membranous urethral support in men besides innervation. Therefore, preservation of peri-sphincteric structures during surgery is recommended. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e518 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jonathan Lopater Suresnes, France More articles by this author Antoine Scherrer Suresnes, France More articles by this author Servane Gey Paris, France More articles by this author Vincent Delmas Paris, France More articles by this author Yann Neuzillet Suresnes, France More articles by this author Thierry Lebret Suresnes, France More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

The effects of a self-selected nap opportunity on the psychophysiological, performance and subjective measures during a simulated industrial night shift regimen

This study compared the effects of a 1 h self-selected recovery period to those of a standard night shift arrangement (with a total break time of 1-h) over a simulated three-day night shift schedule in a laboratory setting. Results showed that the inclusion of the flexible nap scheme resulted in higher performance output, improvements in physiological strain responses and reduced sleepiness during each night shift and generally over the three-night cycle. Certain variables also revealed the impact of napping compared with the standard rest break condition on the circadian rhythm. The sleep diary records show that the inclusion of the current intervention did not significantly reduce daytime recovery sleep. The results suggest that the potential benefits of flexible napping may outweigh the logistical effort it requires in a workplace environment. Practitioner summary: Consensus on appropriate napping strategies for shift work remains a challenge. This simulated night shift laboratory study sought to determine the effects of a 1-h self-selected nap opportunity relative to a normal shift set-up. The nap improved performance and decreased sleepiness, without affecting daytime sleep.

Reduced Slow-Wave Rebound during Daytime Recovery Sleep in Middle-Aged Subjects

Cortical synchronization during NREM sleep, characterized by electroencephalographic slow waves (SW <4Hz and >75 µV), is strongly related to the number of hours of wakefulness prior to sleep and to the quality of the waking experience. Whether a similar increase in wakefulness length leads to a comparable enhancement in NREM sleep cortical synchronization in young and older subjects is still a matter of debate in the literature. Here we evaluated the impact of 25-hours of wakefulness on SW during a daytime recovery sleep episode in 29 young (27y ±5), and 34 middle-aged (51y ±5) subjects. We also assessed whether age-related changes in NREM sleep cortical synchronization predicts the ability to maintain sleep during daytime recovery sleep. Compared to baseline sleep, sleep efficiency was lower during daytime recovery sleep in both age-groups but the effect was more prominent in the middle-aged than in the young subjects. In both age groups, SW density, amplitude, and slope increased whereas SW positive and negative phase duration decreased during daytime recovery sleep compared to baseline sleep, particularly in anterior brain areas. Importantly, compared to young subjects, middle-aged participants showed lower SW density rebound and SW positive phase duration enhancement after sleep deprivation during daytime recovery sleep. Furthermore, middle-aged subjects showed lower SW amplitude and slope enhancements after sleep deprivation than young subjects in frontal and prefrontal derivations only. None of the SW characteristics at baseline were associated with daytime recovery sleep efficiency. Our results support the notion that anterior brain areas elicit and may necessitate more intense recovery and that aging reduces enhancement of cortical synchronization after sleep loss, particularly in these areas. Age-related changes in the quality of wake experience may underlie age-related reduction in markers of cortical synchronization enhancement after sustained wakefulness.

Effects of caffeine on daytime recovery sleep: A double challenge to the sleep–wake cycle in aging

Background and objective Caffeine is the most widely used stimulant to counteract the effects of sleepiness, but it also produces important detrimental effects on subsequent sleep, especially when sleep is initiated at a time when the biological clock sends a strong waking signal such as during daytime. This study compares the effects of caffeine on daytime recovery sleep in young (20–30 y.) and middle-aged subjects (45–60 y.). Methods Subjects participated in both caffeine (200 mg) and placebo conditions (double-blind cross-over design), spaced one month apart. For each condition, subjects initially came to the laboratory for a nocturnal sleep episode. Daytime recovery sleep started in the morning after 25 h of wakefulness. Subjects were administered either one caffeine (100 mg) or placebo capsule three hours before daytime recovery sleep and the remaining dose one hour before daytime recovery sleep. Results Middle-aged subjects showed greater decrements of sleep duration and sleep efficiency than young subjects during daytime recovery under placebo compared to nocturnal sleep. Caffeine decreased sleep efficiency, sleep duration, slow-wave sleep (SWS) and REM sleep during daytime recovery sleep similarly in both age groups. Caffeine also reduced N-REM sleep EEG synchronization during daytime recovery sleep (reduced delta, theta, and alpha power, and greater beta power). Conclusions The combined influence of age and caffeine made the sleep of middle-aged subjects particularly vulnerable to the circadian waking signal. We propose that lower brain synchronization due to age and caffeine produces greater difficulty in overriding the circadian waking signal during daytime sleep and leads to fragmented sleep. These results have implications for the high proportion of the population using caffeine to cope with night work and jet lag, particularly the middle-aged.

Wake Detection Capacity of Actigraphy During Sleep

To evaluate the ability of actigraphy compared to polysomnography (PSG) to detect wakefulness in subjects submitted to 3 sleep conditions with different amounts of wakefulness: a nocturnal sleep episode and 2 daytime recovery sleep episodes, one with placebo and one with caffeine. A second objective was to compare the ability of 4 different scoring algorithms (2 threshold algorithms and 2 regression analysis algorithms) to detect wake in the 3 sleep conditions. Three nights of simultaneous actigraphy (Actiwatch-L, Mini-Mitter/Respironics) and PSG recordings in a within-subject design. Chronobiology laboratory. Fifteen healthy subjects aged between 20 and 60 years (7M, 8F). 200 mg of caffeine and daytime recovery sleep. An epoch-by-epoch comparison between actigraphy and PSG showed a significant decrease in actigraphy accuracy with increased wakefulness in sleep conditions due to the low sleep specificity of actigraphy (generally <50%). Actigraphy overestimated total sleep time and sleep efficiency more strongly in conditions involving more wakefulness. Compared to the 2 regression algorithms, the 2 threshold algorithms were less able to detect wake when the sleep episode involved more wakefulness, and they tended to alternate more between wake and sleep in the scoring of long periods of wakefulness resulting in an overestimation of the number of awakenings. The very low ability of actigraphy to detect wakefulness casts doubt on its validity to measure sleep quality in clinical populations with fragmented sleep or in situations where the sleep-wake cycle is challenged, such as jet lag and shift work.

Effects of Caffeine are more Marked on Daytime Recovery Sleep than on Nocturnal Sleep

Caffeine is often used to counteract sleepiness generated by sleep deprivation, jet lag, and shift-work, and is consumed at different times of day. Caffeine also has effects on sleep. However, little is known about the interaction between sleep deprivation, circadian timing, and caffeine consumption on sleep. In this study, we compared the effects of caffeine on nocturnal sleep initiated at habitual circadian time and on daytime recovery sleep. Thirty-four moderate caffeine consumers participated in both caffeine (200 mg) and placebo (lactose) conditions in a double-blind crossover design. Seventeen subjects followed their habitual sleep-wake cycle and slept in the laboratory during the night (Night), while 17 subjects were sleep deprived for one night and recovery sleep started in the morning (DayRec). All subjects received a capsule of 100 mg of caffeine (or placebo) 3 h before bedtime, and the remaining dose 1 h before bedtime. Compared to placebo, caffeine lengthened sleep latency, increased stage 1, and reduced stage 2 and slow-wave sleep (SWS) in both groups. However, caffeine reduced sleep efficiency more strongly in the DayRec group, and decreased sleep duration and REM sleep only in that group. The stronger effects of caffeine on daytime recovery sleep compared to nocturnal sleep are probably the consequence of the combined influence of increasing circadian wake propensity drive and the dissipation of homeostatic sleep pressure. We propose that the reduction of SWS by caffeine during daytime sleep increases the impact of the circadian wake signal on sleep. These results have implications for individuals using caffeine during night time.

Relationships between sleep quality and glucose regulation in normal humans.

To define the effects of sleep on glucose regulation, we analyzed plasma glucose levels, insulin secretion rates (ISR), and plasma growth hormone and cortisol levels in normal subjects receiving a constant glucose infusion during nocturnal sleep, nocturnal sleep deprivation, and daytime recovery sleep. Plasma glucose and ISR markedly increased during early nocturnal sleep and returned to presleep levels during late sleep. These changes in glucose and ISR appeared to reflect the predominance of slow-wave (SW) stages in early sleep and of rapid-eye-movement and wake stages in late sleep. Major differences in glucose and ISR profiles were observed during sleep deprivation as glucose and ISR remained essentially stable during the first part of the night and then decreased significantly, despite the persistence of bed rest and constant glucose infusion. During daytime recovery sleep, SW stages were increased, glucose levels peaked earlier than during nocturnal sleep, and the decreases of glucose and ISR in late sleep were reduced by one-half. Thus sleep has important effects on brain and tissue glucose utilization, suggesting that sleep disturbances may adversely affect glucose tolerance.

Measuring Mean Velocities with POGO

Abstract POGO is a simple technique for measuring water transport between the surface and some preselected depth. Equipped with a 12-kHz pinger for tracking and range measurement, a xenon flasher for nighttime relocation, and a VHF beacon for daytime recovery, it has been used over 200 times in the Gulf Stream to measure volume transport and to provide a reference velocity (transport) for geostrophic calculations from pairs of hydrographic stations. This note gives a brief technical description of POGO and how it is used. Loran C was used for navigation in this study, but with the advent of the Global Positioning System (GPS), POGO can be used worldwide.

Recovery within day-time sleep after slow wave sleep suppression

Six subjects had their SWS activity suppressed by acoustic stimulation during a day-time (11.00 h) recovery sleep after a 4 h night sleep (03.00–07.00 h). Sleep was disturbed for a period corresponding to 90% of the duration of a preceding undisturbed baseline sleep (also at 11.00 h and preceded by a 4 h night sleep) and thereafter allowed to continue undisturbed until spontaneous awakening. The results showed that SWS and EEG power density were significantly reduced during suppression and that full recovery occurred before spontaneous awakening. The disturbed sleep was significantly longer than the baseline sleep. The increase in duration consisted mainly of SWS, stage 2 and REM. The results suggest that the suppression of SWS activity caused a need for an extension of sleep in order to allow recovery.

EEG power density during recovery sleep in the morning

Sleep was recorded under baseline conditions (waking prior to sleep 16 h; lights off 23.00 h) and during recovery sleep in the morning (walking prior to sleep 24 h; lights off 07.00 h). Slow-wave activity (SWA; EEG power density in the range of 0.75–4.5 Hz) declined progressively over consecutive nonREM-REM cycles in both conditions despite the different circadian phase at which sleep occurred. SWA in nonREM sleep in the first 5 h of sleep was significantly higher in recovery than in baseline. Also SWA within the first 20 min of nonREM-episodes 2 and 3 was significantly higher in recovery sleep, and a tendency in the same direction was seen for nonREM-episode 1. These data show that homeostatic processes are expressed in the EEG also when sleep is initiated at a circadian phase where REM sleep propensity is high. However, comparison of the power spectrum in the first cycle of day-time recovery sleep with published data on recovery sleep at various circadian phases suggests that circadian factors influence the EEG spectra.

Effects of seganserin, a 5-HT 2 antagonist, and temazepam on human sleepsstages and EEG power spectra

The effects of seganserin, a specific 5HT 2 antagonist, on human sleep were assessed in two experiments and compared to the effects of temazepam and sleep deprivation. During daytime recovery sleep after sleep derivation, seganserin did not significantly enhance visually scored slow wave sleep (SWS, stages 3+4) or the EEG power density in the delta frequencies. Under these conditions temazepam reduced the power density in the delta and theta frequencies. During nightime sleep after a nap in the evening, seganserin caused an increase in SWS, a reduction in intermittent wakefulness, and an enhancement of the power density in the delta and theta frequencies during non-rapid eye movement (NREM) sleep. Temazepam induced a reduction in the power density in the delta and theta frequencies. It is concluded that the 5HT 2 antagonist, seganserin, can induce SWS. However, since the spectral results showed that the changes in the sleep EEG were not identical to those induced by sleep deprivation it seems premature to conclude that 5HT 2 receptors are primarily involved in NREM sleep regulation.