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Sample records for human sleep propensity

  1. Sleep quality, sleep propensity and academic performance.

    Science.gov (United States)

    Howell, Andrew J; Jahrig, Jesse C; Powell, Russell A

    2004-10-01

    We examined associations between measures of sleep propensity on the Epworth Sleepiness Scale, sleep quality on the Pittsburgh Sleep Quality Index and academic performance by GPA and grades in introductory psychology for 414 students. In the total sample, neither sleep propensity nor sleep quality correlated with GPA or introductory psychology grades. However, among students carrying a full course load, those reporting poor sleep quality performed less well on academic measures than those reporting a better quality of sleep. Further research is needed to assess the moderating influence of overall demands of daytime functioning on the association between sleep quality and academic performance.

  2. Sleep Duration and Sleep Quality following Acute Mild Traumatic Brain Injury: A Propensity Score Analysis

    Directory of Open Access Journals (Sweden)

    Ting-Yun Huang

    2015-01-01

    Full Text Available Introduction. Mild traumatic brain injury (mTBI has been widely studied and the effects of injury can be long term or even lifelong. This research aims to characterize the sleep problems of patients following acute mTBI. Methods. A total of 171 patients with mTBI within one month and 145 non-mTBI controls were recruited in this study. The questionnaire, Pittsburgh Sleep Quality Index (PSQI, was used to evaluate seven aspects of sleep problems. A propensity score method was used to generate a quasirandomized design to account for the background information, including gender, age, Beck’s Anxiety Index, Beck’s Depression Index, and Epworth Sleepiness Scale. The effect was evaluated via cumulative logit regression including propensity scores as a covariate. Results. Before adjustment, about 60% mTBI patients and over three quarters of control subjects had mild sleep disturbance while one third mTBI patients had moderate sleep disturbance. After adjusting by the propensity scores, the scores of sleep quality and duration were significant between mTBI and control groups. Conclusion. Our study supports that sleep problem is common in mTBI group. After adjusting the confounders by propensity score, sleep duration and subjective sleep quality are the most frequently reported problems in mTBI patients within one month after the injury.

  3. Factors Affecting the Propensity of Tsetse Flies to Enter Houses and Attack Humans Inside: Increased Risk of Sleeping Sickness in Warmer Climates

    Science.gov (United States)

    Vale, Glyn A.; Hargrove, John W.; Chamisa, Andrew; Hall, David R.; Mangwiro, Clement; Torr, Stephen J.

    2013-01-01

    Background Sleeping sickness, or human African trypanosomiasis, is caused by two species of Trypanosoma brucei that are transmitted to humans by tsetse flies (Glossina spp.) when these insects take a bloodmeal. It is commonly assumed that humans must enter the normal woodland habitat of the flies to become infected, but recent studies found that tsetse frequently attack humans inside buildings. Factors affecting human/tsetse contact in buildings need identification. Methodology/Principal Findings In Zimbabwe, tsetse were allowed access to a house via an open door. Those in the house at sunset, and those alighting on humans in the house during the day, were caught using hand-nets. Total catches were unaffected by: (i) the presence of humans in the house and at the door, (ii) wood smoke from a fire inside the house or just outside, (iii) open windows, and (iv) chemicals simulating the odor of cattle or of humans. Catches increased about 10-fold with rising ambient temperatures, and during the hottest months the proportion of the total catch that was taken from the humans increased from 5% to 13%. Of the tsetse caught from humans, 62% consisted of female G. morsitans morstans and both sexes of G. pallidipes, i.e., the group of tsetse that normally alight little on humans. Some of the tsetse caught were old enough to be effective vectors. Conclusion/Significance Present results confirm previous suggestions that buildings provide a distinctive and important venue for transmission of sleeping sickness, especially since the normal repellence of humans and smoke seems poorly effective in such places. The importance of the venue would be increased in warmer climates. PMID:23638209

  4. Sleep and risk-taking propensity in life history and evolutionary perspectives

    OpenAIRE

    Rucas, Stacey L; Alissa A. Miller

    2013-01-01

    Tradeoffs between time allocated to sleeping versus waking result from variations in local ecologies and should correlate to alterations in behavioral life history strategies.  It was predicted that firefighters who sleep less, with lower overall sleep quality, would exhibit greater motivation for risk-taking, an important component of fast life histories.  Firefighters completed evolutionarily relevant questionnaires on five domains of risk-taking propensity that were correlated to sleep qua...

  5. Natural history of excessive daytime sleepiness: role of obesity, weight loss, depression, and sleep propensity.

    Science.gov (United States)

    Fernandez-Mendoza, Julio; Vgontzas, Alexandros N; Kritikou, Ilia; Calhoun, Susan L; Liao, Duanping; Bixler, Edward O

    2015-03-01

    Excessive daytime sleepiness (EDS) is highly prevalent in the general population and is associated with occupational and public safety hazards. However, no study has examined the clinical and polysomnographic (PSG) predictors of the natural history of EDS. Representative longitudinal study. Sleep laboratory. From a random, general population sample of 1,741 individuals of the Penn State Adult Cohort, 1,395 were followed up after 7.5 years. Full medical evaluation and 1-night PSG at baseline and standardized telephone interview at follow-up. The incidence of EDS was 8.2%, while its persistence and remission were 38% and 62%, respectively. Obesity and weight gain were associated with the incidence and persistence of EDS, while weight loss was associated with its remission. Significant interactions between depression and PSG parameters on incident EDS showed that, in depressed individuals, incident EDS was associated with sleep disturbances, while in non-depressed individuals, incident EDS was associated with increased physiologic sleep propensity. Diabetes, allergy/ asthma, anemia, and sleep complaints also predicted the natural history of EDS. Obesity, a disorder of epidemic proportions, is a major risk factor for the incidence and chronicity of EDS, while weight loss is associated with its remission. Interestingly, objective sleep disturbances predict incident EDS in depressed individuals, whereas physiologic sleep propensity predicts incident EDS in those without depression. Weight management and treatment of depression and sleep disorders should be part of our public health policies. © 2015 Associated Professional Sleep Societies, LLC.

  6. Sleep and Human Aging.

    Science.gov (United States)

    Mander, Bryce A; Winer, Joseph R; Walker, Matthew P

    2017-04-05

    Older adults do not sleep as well as younger adults. Why? What alterations in sleep quantity and quality occur as we age, and are there functional consequences? What are the underlying neural mechanisms that explain age-related sleep disruption? This review tackles these questions. First, we describe canonical changes in human sleep quantity and quality in cognitively normal older adults. Second, we explore the underlying neurobiological mechanisms that may account for these human sleep alterations. Third, we consider the functional consequences of age-related sleep disruption, focusing on memory impairment as an exemplar. We conclude with a discussion of a still-debated question: do older adults simply need less sleep, or rather, are they unable to generate the sleep that they still need? Copyright © 2017. Published by Elsevier Inc.

  7. Natural History of Excessive Daytime Sleepiness: Role of Obesity, Weight Loss, Depression, and Sleep Propensity

    Science.gov (United States)

    Fernandez-Mendoza, Julio; Vgontzas, Alexandros N.; Kritikou, Ilia; Calhoun, Susan L.; Liao, Duanping; Bixler, Edward O.

    2015-01-01

    Study Objectives: Excessive daytime sleepiness (EDS) is highly prevalent in the general population and is associated with occupational and public safety hazards. However, no study has examined the clinical and polysomnographic (PSG) predictors of the natural history of EDS. Design: Representative longitudinal study. Setting: Sleep laboratory. Participants: From a random, general population sample of 1,741 individuals of the Penn State Adult Cohort, 1,395 were followed up after 7.5 years. Measurements and Results: Full medical evaluation and 1-night PSG at baseline and standardized telephone interview at follow-up. The incidence of EDS was 8.2%, while its persistence and remission were 38% and 62%, respectively. Obesity and weight gain were associated with the incidence and persistence of EDS, while weight loss was associated with its remission. Significant interactions between depression and PSG parameters on incident EDS showed that, in depressed individuals, incident EDS was associated with sleep disturbances, while in non-depressed individuals, incident EDS was associated with increased physiologic sleep propensity. Diabetes, allergy/asthma, anemia, and sleep complaints also predicted the natural history of EDS. Conclusions: Obesity, a disorder of epidemic proportions, is a major risk factor for the incidence and chronicity of excessive daytime sleepiness (EDS), while weight loss is associated with its remission. Interestingly, objective sleep disturbances predict incident EDS in depressed individuals, whereas physiologic sleep propensity predicts incident EDS in those without depression. Weight management and treatment of depression and sleep disorders should be part of public health policies. Citation: Fernandez-Mendoza J, Vgontzas AN, Kritikou I, Calhoun SL, Liao D, Bixler EO. Natural history of excessive daytime sleepiness: role of obesity, weight loss, depression, and sleep propensity. SLEEP 2015;38(3):351–360. PMID:25581913

  8. Gender, sleep problems, and obesity in Taiwan: a propensity-score-matching approach.

    Science.gov (United States)

    Chen, Duan-Rung; Kuan, Ping-Yin

    2015-01-01

    Obesity has become a major health risk in industrialized countries, with disturbed sleep identified as a correlate. This study used data drawn from Taiwan's 2005 Social Development Trend Survey on Health and Safety and the propensity-score-matching method to shed light on gender-specific associations between sleep problems and obesity among 24,113 adults aged 20-64 years. The average increase in obesity prevalence among respondents with disrupted sleep was 1.85%, as compared to those who did not report disrupted sleep, with similar psycho-social attributes. Similarly, the prevalence of obesity among those who reported restless sleep was increased by an average of 1.40% compared to those who did not report restless sleep with similar psycho-social attributes. We also found gender-specific vulnerability to different types of sleep problems. Among men who reported disrupted sleep, we found a 3.12% increase in the prevalence of obesity. Among women exposed to restless sleep, the increase in obesity prevalence was 1.84%. The observed gender difference in the prevalence of increases in obesity may be attributed to gender-specific behavioral responses to poor sleep. With poor sleep, men may respond to hunger by overeating; women may respond by physical inactivity. Both can contribute to an elevated risk of obesity.

  9. Human genetics and sleep behavior

    OpenAIRE

    Shi, G; D. Wu; Ptacek, LJ; Fu, Y-H

    2017-01-01

    Why we sleep remains one of the greatest mysteries in science. In the past few years, great advances have been made to better understand this phenomenon. Human genetics has contributed significantly to this movement, as many features of sleep have been found to be heritable. Discoveries about these genetic variations that affect human sleep will aid us in understanding the underlying mechanism of sleep. Here we summarize recent discoveries about the genetic variations affecting the timing of ...

  10. Sleep and circadian rhythms in humans.

    Science.gov (United States)

    Czeisler, C A; Gooley, J J

    2007-01-01

    During the past 50 years, converging evidence reveals that the fundamental properties of the human circadian system are shared in common with those of other organisms. Concurrent data from multiple physiological rhythms in humans revealed that under some conditions, rhythms oscillated at different periods within the same individuals and led to the conclusion 30 years ago that the human circadian system was composed of multiple oscillators organized hierarchically; this inference has recently been confirmed using molecular techniques in species ranging from unicellular marine organisms to mammals. Although humans were once thought to be insensitive to the resetting effects of light, light is now recognized as the principal circadian synchronizer in humans, capable of eliciting weak (Type 1) or strong (Type 0) resetting, depending on stimulus strength and timing. Realization that circadian photoreception could be maintained in the absence of sight was first recognized in blind humans, as was the property of adaptation of the sensitivity of circadian photoreception to prior light history. In sighted humans, the intrinsic circadian period is very tightly distributed around approximately 24.2 hours and exhibits aftereffects of prior entrainment. Phase angle of entrainment is dependent on circadian period, at least in young adults. Circadian pacemakers in humans drive daily variations in many physiologic and behavioral variables, including circadian rhythms in alertness and sleep propensity. Under entrained conditions, these rhythms interact with homeostatic regulation of the sleep/wake cycle to determine the ability to sustain vigilance during the day and to sleep at night. Quantitative understanding of the fundamental properties of the multioscillator circadian system in humans and their interaction with sleep/wake homeostasis has many applications to health and disease, including the development of treatments for circadian rhythm and sleep disorders.

  11. Energy expenditure during sleep, sleep deprivation and sleep following sleep deprivation in adult humans

    OpenAIRE

    Jung, Christopher M.; Melanson, Edward L.; Frydendall, Emily J; Perreault, Leigh; Robert H Eckel; Wright, Kenneth P.

    2010-01-01

    Sleep has been proposed to be a physiological adaptation to conserve energy, but little research has examined this proposed function of sleep in humans. We quantified effects of sleep, sleep deprivation and recovery sleep on whole-body total daily energy expenditure (EE) and on EE during the habitual day and nighttime. We also determined effects of sleep stage during baseline and recovery sleep on EE. Seven healthy participants aged 22 ± 5 years (mean ± s.d.) maintained ∼8 h per night sleep s...

  12. Human adult deglutition during sleep.

    Science.gov (United States)

    Sato, Kiminori; Nakashima, Tadashi

    2006-05-01

    Clearance of the pharynx by deglutition is important in protecting the airway. The pattern of deglutition during sleep was investigated. Deglutition during sleep was examined in 8 normal human adults via time-matched recordings of polysomnography and surface electromyography (EMG) of the thyrohyoid and suprahyoid muscles. During sleep, deglutition was episodic, and was absent for long periods. The mean number of swallows per hour (+/-SD) during the total sleep time was 2.9 +/- 1.3. The mean period of the longest absence of deglutition was 50.6 +/- 10.2 minutes. Most deglutition occurred in association with spontaneous electroencephalographic arousal in rapid eye movement (REM) sleep and non-REM sleep. Deglutition was related to sleep stage. The mean number of swallows per hour was 7.2 +/- 3.5 during stage 1 sleep and 2.0 +/- 0.7 during stage 2 sleep. There was little deglutition during stages 3 and 4. The deeper the sleep stage became, the lower the mean deglutition frequency became. The mean number of swallows per hour was 2.7 +/- 2.2 during REM sleep. The EMG amplitude dropped to the lowest level of recording and hypotonic EMG activity increased during REM sleep. Deglutition, a vital function, is infrequent during sleep.

  13. Shining evolutionary light on human sleep and sleep disorders.

    Science.gov (United States)

    Nunn, Charles L; Samson, David R; Krystal, Andrew D

    2016-01-01

    Sleep is essential to cognitive function and health in humans, yet the ultimate reasons for sleep-i.e. 'why' sleep evolved-remain mysterious. We integrate findings from human sleep studies, the ethnographic record, and the ecology and evolution of mammalian sleep to better understand sleep along the human lineage and in the modern world. Compared to other primates, sleep in great apes has undergone substantial evolutionary change, with all great apes building a sleeping platform or 'nest'. Further evolutionary change characterizes human sleep, with humans having the shortest sleep duration, yet the highest proportion of rapid eye movement sleep among primates. These changes likely reflect that our ancestors experienced fitness benefits from being active for a greater portion of the 24-h cycle than other primates, potentially related to advantages arising from learning, socializing and defending against predators and hostile conspecifics. Perspectives from evolutionary medicine have implications for understanding sleep disorders; we consider these perspectives in the context of insomnia, narcolepsy, seasonal affective disorder, circadian rhythm disorders and sleep apnea. We also identify how human sleep today differs from sleep through most of human evolution, and the implications of these changes for global health and health disparities. More generally, our review highlights the importance of phylogenetic comparisons in understanding human health, including well-known links between sleep, cognitive performance and health in humans. © The Author(s) 2016. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.

  14. Shining evolutionary light on human sleep and sleep disorders

    Science.gov (United States)

    Nunn, Charles L.; Samson, David R.; Krystal, Andrew D.

    2016-01-01

    Sleep is essential to cognitive function and health in humans, yet the ultimate reasons for sleep—i.e. ‘why’ sleep evolved—remain mysterious. We integrate findings from human sleep studies, the ethnographic record, and the ecology and evolution of mammalian sleep to better understand sleep along the human lineage and in the modern world. Compared to other primates, sleep in great apes has undergone substantial evolutionary change, with all great apes building a sleeping platform or ‘nest’. Further evolutionary change characterizes human sleep, with humans having the shortest sleep duration, yet the highest proportion of rapid eye movement sleep among primates. These changes likely reflect that our ancestors experienced fitness benefits from being active for a greater portion of the 24-h cycle than other primates, potentially related to advantages arising from learning, socializing and defending against predators and hostile conspecifics. Perspectives from evolutionary medicine have implications for understanding sleep disorders; we consider these perspectives in the context of insomnia, narcolepsy, seasonal affective disorder, circadian rhythm disorders and sleep apnea. We also identify how human sleep today differs from sleep through most of human evolution, and the implications of these changes for global health and health disparities. More generally, our review highlights the importance of phylogenetic comparisons in understanding human health, including well-known links between sleep, cognitive performance and health in humans. PMID:27470330

  15. Integration of human sleep-wake regulation and circadian rhythmicity

    Science.gov (United States)

    Dijk, Derk-Jan; Lockley, Steven W.

    2002-01-01

    The human sleep-wake cycle is generated by a circadian process, originating from the suprachiasmatic nuclei, in interaction with a separate oscillatory process: the sleep homeostat. The sleep-wake cycle is normally timed to occur at a specific phase relative to the external cycle of light-dark exposure. It is also timed at a specific phase relative to internal circadian rhythms, such as the pineal melatonin rhythm, the circadian sleep-wake propensity rhythm, and the rhythm of responsiveness of the circadian pacemaker to light. Variations in these internal and external phase relationships, such as those that occur in blindness, aging, morning and evening, and advanced and delayed sleep-phase syndrome, lead to sleep disruptions and complaints. Changes in ocular circadian photoreception, interindividual variation in the near-24-h intrinsic period of the circadian pacemaker, and sleep homeostasis can contribute to variations in external and internal phase. Recent findings on the physiological and molecular-genetic correlates of circadian sleep disorders suggest that the timing of the sleep-wake cycle and circadian rhythms is closely integrated but is, in part, regulated differentially.

  16. Fruit Flies Help Human Sleep Research

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    Skip Navigation Bar Home Current Issue Past Issues Fruit Flies Help Human Sleep Research Past Issues / Summer ... courtesy of NIGMS Neuroscientist Chiara Cirelli uses experimental fruit flies to study sleep. Although it may be ...

  17. Can sleep deprivation studies explain why human adults sleep?

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    Brown, Lee K

    2012-11-01

    This review will concentrate on the consequences of sleep deprivation in adult humans. These findings form a paradigm that serves to demonstrate many of the critical functions of the sleep states. The drive to obtain food, water, and sleep constitutes important vegetative appetites throughout the animal kingdom. Unlike nutrition and hydration, the reasons for sleep have largely remained speculative. When adult humans are nonspecifically sleep-deprived, systemic effects may include defects in cognition, vigilance, emotional stability, risk-taking, and, possibly, moral reasoning. Appetite (for foodstuffs) increases and glucose intolerance may ensue. Procedural, declarative, and emotional memory are affected. Widespread alterations of immune function and inflammatory regulators can be observed, and functional MRI reveals profound changes in regional cerebral activity related to attention and memory. Selective deprivation of rapid eye movement (REM) sleep, on the contrary, appears to be more activating and to have lesser effects on immunity and inflammation. The findings support a critical need for sleep due to the widespread effects on the adult human that result from nonselective sleep deprivation. The effects of selective REM deprivation appear to be different and possibly less profound, and the functions of this sleep state remain enigmatic.

  18. Models of human sleep regulation

    NARCIS (Netherlands)

    Beersma, Domien G.M.

    1998-01-01

    Non-REM sleep deprivation and REM sleep deprivation both lead to specific rebounds, suggesting that these states fulfil physiological needs. In view of impaired performance after sleep deprivation, a recovery function of sleep seems likely. The timing of this recovery is restricted to a narrow time

  19. Circadian Rhythms, Sleep Deprivation, and Human Performance

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    Goel, Namni; Basner, Mathias; Rao, Hengyi; Dinges, David F.

    2014-01-01

    Much of the current science on, and mathematical modeling of, dynamic changes in human performance within and between days is dominated by the two-process model of sleep–wake regulation, which posits a neurobiological drive for sleep that varies homeostatically (increasing as a saturating exponential during wakefulness and decreasing in a like manner during sleep), and a circadian process that neurobiologically modulates both the homeostatic drive for sleep and waking alertness and performance. Endogenous circadian rhythms in neurobehavioral functions, including physiological alertness and cognitive performance, have been demonstrated using special laboratory protocols that reveal the interaction of the biological clock with the sleep homeostatic drive. Individual differences in circadian rhythms and genetic and other components underlying such differences also influence waking neurobehavioral functions. Both acute total sleep deprivation and chronic sleep restriction increase homeostatic sleep drive and degrade waking neurobehavioral functions as reflected in sleepiness, attention, cognitive speed, and memory. Recent evidence indicating a high degree of stability in neurobehavioral responses to sleep loss suggests that these trait-like individual differences are phenotypic and likely involve genetic components, including circadian genes. Recent experiments have revealed both sleep homeostatic and circadian effects on brain metabolism and neural activation. Investigation of the neural and genetic mechanisms underlying the dynamically complex interaction between sleep homeostasis and circadian systems is beginning. A key goal of this work is to identify biomarkers that accurately predict human performance in situations in which the circadian and sleep homeostatic systems are perturbed. PMID:23899598

  20. REM sleep complicates period adding bifurcations from monophasic to polyphasic sleep behavior in a sleep-wake regulatory network model for human sleep

    OpenAIRE

    Kalmbach, K.; Booth, V.; Behn, C. G. Diniz

    2017-01-01

    The structure of human sleep changes across development as it consolidates from the polyphasic sleep of infants to the single nighttime sleep period typical in adults. Across this same developmental period, time scales of the homeostatic sleep drive, the physiological drive to sleep that increases with time spent awake, also change and presumably govern the transition from polyphasic to monophasic sleep behavior. Using a physiologically-based, sleep-wake regulatory network model for human sle...

  1. A neglected aspect of the epidemiology of sleeping sickness: the propensity of the tsetse fly vector to enter houses.

    Science.gov (United States)

    Vale, Glyn A; Chamisa, Andrew; Mangwiro, Clement; Torr, Stephen J

    2013-01-01

    When taking a bloodmeal from humans, tsetse flies can transmit the trypanosomes responsible for sleeping sickness, or human African trypanosomiasis. While it is commonly assumed that humans must enter the normal woodland habitat of the tsetse in order to have much chance of contacting the flies, recent studies suggested that important contact can occur due to tsetse entering buildings. Hence, we need to know more about tsetse in buildings, and to understand why, when and how they enter such places. Buildings studied were single storied and comprised a large house with a thatched roof and smaller houses with roofs of metal or asbestos. Each building was unoccupied except for the few minutes of its inspection every two hours, so focusing on the responses of tsetse to the house itself, rather than to humans inside. The composition, and physiological condition of catches of tsetse flies, Glossina morsitans morsitans and G. pallidipes, in the houses and the diurnal and seasonal pattern of catches, were intermediate between these aspects of the catches from artificial refuges and a host-like trap. Several times more tsetse were caught in the large house, as against the smaller structures. Doors and windows seemed about equally effective as entry points. Many of the tsetse in houses were old enough to be potential vectors of sleeping sickness, and some of the flies alighted on the humans that inspected the houses. Houses are attractive in themselves. Some of the tsetse attracted seem to be in a host-seeking phase of behavior and others appear to be looking for shelter from high temperatures outside. The risk of contracting sleeping sickness in houses varies according to house design.

  2. Analysis of the Relationship between Sleep Duration and Body Mass Index in a South Korean Adult Population: A Propensity Score Matching Approach.

    Science.gov (United States)

    Sung, Baksun

    2017-07-01

    One-third of the present adults in South Korea are obese, and previous studies have demonstrated that sleep duration is considered a risk factor for obesity. Hence, I assessed the relationship between sleep duration and body mass index in a South Korean adult population. This cross-sectional study consists of a representative sample of 4,218 South Korean adults (20-64 years) who participated in the sixth Korea National Health and Nutrition Examination Survey (2015). As statistical analysis methods, data were analyzed using chi-square test and multiple logistic regression. Propensity score matching (PSM) was applied to control selection bias, and obesity-related factors were used as covariates in PSM. According to the multiple logistic regression analysis, people who sleep for more than seven hours a day were less likely to be obese than those who sleep for less than seven hours a day in the pre-match (OR = 0.75, 95%CI = 0.65-0.88) and post-match (OR = 0.77, 95%CI = 0.65-0.90) samples. This finding suggests that South Korean adults who reported sleeping more than 7 hours a day were linked to decreased body mass index. Hence, the proper amount of sleep is necessary to reduce the prevalence of obesity in this population.

  3. Structural brain correlates of human sleep oscillations.

    Science.gov (United States)

    Saletin, Jared M; van der Helm, Els; Walker, Matthew P

    2013-12-01

    Sleep is strongly conserved within species, yet marked and perplexing inter-individual differences in sleep physiology are observed. Combining EEG sleep recordings and high-resolution structural brain imaging, here we demonstrate that the morphology of the human brain offers one explanatory factor of such inter-individual variability. Gray matter volume in interoceptive and exteroceptive cortices correlated with the expression of slower NREM sleep spindle frequencies, supporting their proposed role in sleep protection against conscious perception. Conversely, and consistent with an involvement in declarative memory processing, gray matter volume in bilateral hippocampus was associated with faster NREM sleep spindle frequencies. In contrast to spindles, gray matter volume in the homeostatic sleep-regulating center of the basal forebrain/hypothalamus, together with the medial prefrontal cortex, accounted for individual differences in NREM slow wave oscillations. Together, such findings indicate that the qualitative and quantitative expression of human sleep physiology is significantly related to anatomically specific differences in macroscopic brain structure. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. In short photoperiods, human sleep is biphasic.

    Science.gov (United States)

    Wehr

    1992-06-01

    Results of a photoperiod experiment show that human sleep can be unconsolidated and polyphasic, like the sleep of other animals. When normal individuals were transferred from a conventional 16-h photoperiod to an experimental 10-h photo-period, their sleep episodes expanded and usually divided into two symmetrical bouts, several hours in duration, with a 1-3 h waking interval between them. The durations of nocturnal melatonin secretion and of the nocturnal phase of rising sleepiness (measured in a constant routine protocol) also expanded, indicating that the timing of internal processes that control sleep and melatonin, such as circadian rhythms, had been modified by the change in photoperiod. Previous work suggests that the experimental results could be simulated with dual-oscillators, entrained separately to dawn and dusk, or with a two-process model, having a lowered threshold for sleep-onset during the scotoperiod.

  5. Human apolipoprotein E4 targeted replacement in mice reveals increased susceptibility to sleep disruption and intermittent hypoxia

    Science.gov (United States)

    Kaushal, Navita; Ramesh, Vijay

    2012-01-01

    Intermittent hypoxia (IH) and sleep fragmentation (SF) are major manifestations of sleep apnea, a frequent condition in aging humans. Sleep perturbations are frequent in Alzheimer's disease (AD) and may underlie the progression of disease. We hypothesized that acute short-term IH, SF, and their combination (IH+SF) may reveal unique susceptibility in sleep integrity in a murine model of AD. The effects of acute IH, SF, and IH+SF on sleep architecture, delta power, sleep latency, and core body temperature were assessed in adult male human ApoE4-targeted replacement mice (hApoE4) and wild-type (WT) controls. Slow wave sleep (SWS) was significantly reduced, and rapid eye movement (REM) sleep was almost abolished during acute exposure to IH alone and IH+SF for 6 h in hApoE4, with milder effects in WT controls. Decreased delta power during SWS did not show postexposure rebound in hApoE4 unlike WT controls. IH and IH+SF induced hypothermia, which was more prominent in hApoE4 than WT controls. Mice subjected to SF also showed sleep deficits but without hypothermia. hApoE4 mice, unlike WT controls, exhibited increased sleep propensity, especially following IH and IH+SF, suggesting limited ability for sleep recovery in hApoE4 mice. These findings substantiate the potential impact of IH and SF in modulating sleep architecture and sleep homeostasis including maintenance of body temperature. Furthermore, the increased susceptibility and limited recovery ability of hApoE4 mice to sleep apnea suggests that early recognition and treatment of the latter in AD patients may restrict the progression and clinical manifestations of this frequent neurodegenerative disorder. PMID:22573105

  6. Sleep intensity and the evolution of human cognition.

    Science.gov (United States)

    Samson, David R; Nunn, Charles L

    2015-01-01

    Over the past four decades, scientists have made substantial progress in understanding the evolution of sleep patterns across the Tree of Life. Remarkably, the specifics of sleep along the human lineage have been slow to emerge. This is surprising, given our unique mental and behavioral capacity and the importance of sleep for individual cognitive performance. One view is that our species' sleep architecture is in accord with patterns documented in other mammals. We promote an alternative view, that human sleep is highly derived relative to that of other primates. Based on new and existing evidence, we specifically propose that humans are more efficient in their sleep patterns than are other primates, and that human sleep is shorter, deeper, and exhibits a higher proportion of REM than expected. Thus, we propose the sleep intensity hypothesis: Early humans experienced selective pressure to fulfill sleep needs in the shortest time possible. Several factors likely served as selective pressures for more efficient sleep, including increased predation risk in terrestrial environments, threats from intergroup conflict, and benefits arising from increased social interaction. Less sleep would enable longer active periods in which to acquire and transmit new skills and knowledge, while deeper sleep may be critical for the consolidation of those skills, leading to enhanced cognitive abilities in early humans. © 2015 Wiley Periodicals, Inc.

  7. A Multispecies Approach to Co-Sleeping : Integrating Human-Animal Co-Sleeping Practices into Our Understanding of Human Sleep.

    Science.gov (United States)

    Smith, Bradley P; Hazelton, Peta C; Thompson, Kirrilly R; Trigg, Joshua L; Etherton, Hayley C; Blunden, Sarah L

    2017-09-01

    Human sleeping arrangements have evolved over time and differ across cultures. The majority of adults share their bed at one time or another with a partner or child, and many also sleep with pets. In fact, around half of dog and cat owners report sharing a bed or bedroom with their pet(s). However, interspecies co-sleeping has been trivialized in the literature relative to interpersonal or human-human co-sleeping, receiving little attention from an interdisciplinary psychological perspective. In this paper, we provide a historical outline of the "civilizing process" that has led to current sociocultural conceptions of sleep as an individual, private function crucial for the functioning of society and the health of individuals. We identify similar historical processes at work in the formation of contemporary constructions of socially normative sleeping arrangements for humans and animals. Importantly, since previous examinations of co-sleeping practices have anthropocentrically framed this topic, the result is an incomplete understanding of co-sleeping practices. By using dogs as an exemplar of human-animal co-sleeping, and comparing human-canine sleeping with adult-child co-sleeping, we determine that both forms of co-sleeping share common factors for establishment and maintenance, and often result in similar benefits and drawbacks. We propose that human-animal and adult-child co-sleeping should be approached as legitimate and socially relevant forms of co-sleeping, and we recommend that co-sleeping be approached broadly as a social practice involving relations with humans and other animals. Because our proposition is speculative and derived from canine-centric data, we recommend ongoing theoretical refinement grounded in empirical research addressing co-sleeping between humans and multiple animal species.

  8. Human gamma oscillations during slow wave sleep.

    Directory of Open Access Journals (Sweden)

    Mario Valderrama

    Full Text Available Neocortical local field potentials have shown that gamma oscillations occur spontaneously during slow-wave sleep (SWS. At the macroscopic EEG level in the human brain, no evidences were reported so far. In this study, by using simultaneous scalp and intracranial EEG recordings in 20 epileptic subjects, we examined gamma oscillations in cerebral cortex during SWS. We report that gamma oscillations in low (30-50 Hz and high (60-120 Hz frequency bands recurrently emerged in all investigated regions and their amplitudes coincided with specific phases of the cortical slow wave. In most of the cases, multiple oscillatory bursts in different frequency bands from 30 to 120 Hz were correlated with positive peaks of scalp slow waves ("IN-phase" pattern, confirming previous animal findings. In addition, we report another gamma pattern that appears preferentially during the negative phase of the slow wave ("ANTI-phase" pattern. This new pattern presented dominant peaks in the high gamma range and was preferentially expressed in the temporal cortex. Finally, we found that the spatial coherence between cortical sites exhibiting gamma activities was local and fell off quickly when computed between distant sites. Overall, these results provide the first human evidences that gamma oscillations can be observed in macroscopic EEG recordings during sleep. They support the concept that these high-frequency activities might be associated with phasic increases of neural activity during slow oscillations. Such patterned activity in the sleeping brain could play a role in off-line processing of cortical networks.

  9. Genetics of rapid eye movement sleep in humans

    OpenAIRE

    Adamczyk, M.; Ambrosius, U; Lietzenmaier, S; Wichniak, A; Holsboer, F.; Friess, E

    2015-01-01

    The trait-like nature of electroencephalogram (EEG) is well established. Furthermore, EEG of wake and non-rapid eye movement (non-REM) sleep has been shown to be highly heritable. However, the genetic effects on REM sleep EEG microstructure are as yet unknown. REM sleep is of special interest since animal and human data suggest a connection between REM sleep abnormalities and the pathophysiology of psychiatric and neurological diseases. Here we report the results of a study in monozygotic (MZ...

  10. Effect of sleep deprivation on the human metabolome.

    Science.gov (United States)

    Davies, Sarah K; Ang, Joo Ern; Revell, Victoria L; Holmes, Ben; Mann, Anuska; Robertson, Francesca P; Cui, Nanyi; Middleton, Benita; Ackermann, Katrin; Kayser, Manfred; Thumser, Alfred E; Raynaud, Florence I; Skene, Debra J

    2014-07-22

    Sleep restriction and circadian clock disruption are associated with metabolic disorders such as obesity, insulin resistance, and diabetes. The metabolic pathways involved in human sleep, however, have yet to be investigated with the use of a metabolomics approach. Here we have used untargeted and targeted liquid chromatography (LC)/MS metabolomics to examine the effect of acute sleep deprivation on plasma metabolite rhythms. Twelve healthy young male subjects remained in controlled laboratory conditions with respect to environmental light, sleep, meals, and posture during a 24-h wake/sleep cycle, followed by 24 h of wakefulness. Two-hourly plasma samples collected over the 48 h period were analyzed by LC/MS. Principal component analysis revealed a clear time of day variation with a significant cosine fit during the wake/sleep cycle and during 24 h of wakefulness in untargeted and targeted analysis. Of 171 metabolites quantified, daily rhythms were observed in the majority (n = 109), with 78 of these maintaining their rhythmicity during 24 h of wakefulness, most with reduced amplitude (n = 66). During sleep deprivation, 27 metabolites (tryptophan, serotonin, taurine, 8 acylcarnitines, 13 glycerophospholipids, and 3 sphingolipids) exhibited significantly increased levels compared with during sleep. The increased levels of serotonin, tryptophan, and taurine may explain the antidepressive effect of acute sleep deprivation and deserve further study. This report, to our knowledge the first of metabolic profiling during sleep and sleep deprivation and characterization of 24 h rhythms under these conditions, offers a novel view of human sleep/wake regulation.

  11. Functional Neuroimaging Insights into the Physiology of Human Sleep

    Science.gov (United States)

    Dang-Vu, Thien Thanh; Schabus, Manuel; Desseilles, Martin; Sterpenich, Virginie; Bonjean, Maxime; Maquet, Pierre

    2010-01-01

    Functional brain imaging has been used in humans to noninvasively investigate the neural mechanisms underlying the generation of sleep stages. On the one hand, REM sleep has been associated with the activation of the pons, thalamus, limbic areas, and temporo-occipital cortices, and the deactivation of prefrontal areas, in line with theories of REM sleep generation and dreaming properties. On the other hand, during non-REM (NREM) sleep, decreases in brain activity have been consistently found in the brainstem, thalamus, and in several cortical areas including the medial prefrontal cortex (MPFC), in agreement with a homeostatic need for brain energy recovery. Benefiting from a better temporal resolution, more recent studies have characterized the brain activations related to phasic events within specific sleep stages. In particular, they have demonstrated that NREM sleep oscillations (spindles and slow waves) are indeed associated with increases in brain activity in specific subcortical and cortical areas involved in the generation or modulation of these waves. These data highlight that, even during NREM sleep, brain activity is increased, yet regionally specific and transient. Besides refining the understanding of sleep mechanisms, functional brain imaging has also advanced the description of the functional properties of sleep. For instance, it has been shown that the sleeping brain is still able to process external information and even detect the pertinence of its content. The relationship between sleep and memory has also been refined using neuroimaging, demonstrating post-learning reactivation during sleep, as well as the reorganization of memory representation on the systems level, sometimes with long-lasting effects on subsequent memory performance. Further imaging studies should focus on clarifying the role of specific sleep patterns for the processing of external stimuli, as well as the consolidation of freshly encoded information during sleep. Citation: Dang

  12. Sleep Deprivation Impairs the Accurate Recognition of Human Emotions

    Science.gov (United States)

    van der Helm, Els; Gujar, Ninad; Walker, Matthew P.

    2010-01-01

    Study Objectives: Investigate the impact of sleep deprivation on the ability to recognize the intensity of human facial emotions. Design: Randomized total sleep-deprivation or sleep-rested conditions, involving between-group and within-group repeated measures analysis. Setting: Experimental laboratory study. Participants: Thirty-seven healthy participants, (21 females) aged 18–25 y, were randomly assigned to the sleep control (SC: n = 17) or total sleep deprivation group (TSD: n = 20). Interventions: Participants performed an emotional face recognition task, in which they evaluated 3 different affective face categories: Sad, Happy, and Angry, each ranging in a gradient from neutral to increasingly emotional. In the TSD group, the task was performed once under conditions of sleep deprivation, and twice under sleep-rested conditions following different durations of sleep recovery. In the SC group, the task was performed twice under sleep-rested conditions, controlling for repeatability. Measurements and Results: In the TSD group, when sleep-deprived, there was a marked and significant blunting in the recognition of Angry and Happy affective expressions in the moderate (but not extreme) emotional intensity range; differences that were most reliable and significant in female participants. No change in the recognition of Sad expressions was observed. These recognition deficits were, however, ameliorated following one night of recovery sleep. No changes in task performance were observed in the SC group. Conclusions: Sleep deprivation selectively impairs the accurate judgment of human facial emotions, especially threat relevant (Anger) and reward relevant (Happy) categories, an effect observed most significantly in females. Such findings suggest that sleep loss impairs discrete affective neural systems, disrupting the identification of salient affective social cues. Citation: van der Helm E; Gujar N; Walker MP. Sleep deprivation impairs the accurate recognition of human

  13. The Effect of Dogs on Human Sleep in the Home Sleep Environment.

    Science.gov (United States)

    Patel, Salma I; Miller, Bernie W; Kosiorek, Heidi E; Parish, James M; Lyng, Philip J; Krahn, Lois E

    2017-09-01

    To objectively assess whether a dog in the bedroom or bed disturbs sleep. From August 1, 2015, through December 31, 2015, we evaluated the sleep of humans and dogs occupying the same bedroom to determine whether this arrangement was conducive to sleep. The study included 40 healthy adults without sleep disorders and their dogs (no dogs dog a validated dog accelerometer for 7 nights. The mean ± SD age of the participants (88% women) was 44±14 years and body mass index was 25±6. The mean ± SD age of the dogs was 5±3 years and weight was 15±13 kg. Mean ± SD actigraphy data showed 475±101 minutes in bed, 404±99 minutes total sleep time, 81%±7% sleep efficiency, and 71±35 minutes wake time after sleep onset. The dogs' accelerometer activity during the corresponding human sleep period was characterized as mean ± SD minutes at rest, active, and at play of 413±102, 62±43, and 2±4. The dogs had mean ± SD 85%±15% sleep efficiency. Human sleep efficiency was lower if the dog was on the bed as opposed to simply in the room (P=.003). Humans with a single dog in their bedroom maintained good sleep efficiency; however, the dog's position on/off the bed made a difference. A dog's presence in the bedroom may not be disruptive to human sleep, as was previously suspected. Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  14. Adolescent sleep patterns in humans and laboratory animals

    Science.gov (United States)

    Hagenauer, Megan Hastings; Lee, Theresa M.

    2016-01-01

    One of the defining characteristics of adolescence in humans is a large shift in the timing and structure of sleep. Some of these changes are easily observable at the behavioral level, such as a shift in sleep patterns from a relatively morning to a relatively evening chronotype. However, there are equally large changes in the underlying architecture of sleep, including a > 60% decrease in slow brain wave activity, which may reflect cortical pruning. In this review we examine the developmental forces driving adolescent sleep patterns using a cross-species comparison. We find that behavioral and physiological sleep parameters change during adolescence in non-human mammalian species, ranging from primates to rodents, in a manner that is often hormone-dependent. However, the overt appearance of these changes is species-specific, with polyphasic sleepers, such as rodents, showing a phase-advance in sleep timing and consolidation of daily sleep/wake rhythms. Using the classic two-process model of sleep regulation, we demonstrate via a series of simulations that many of the species-specific characteristics of adolescent sleep patterns can be explained by a universal decrease in the build-up and dissipation of sleep pressure. Moreover, and counterintuitively, we find that these changes do not necessitate a large decrease in overall sleep need, fitting the adolescent sleep literature. We compare these results to our previous review detailing evidence for adolescent changes in the regulation of sleep by the circadian timekeeping system (Hagenauer and Lee, 2012), and suggest that both processes may be responsible for adolescent sleep patterns. PMID:23998671

  15. Adolescent sleep patterns in humans and laboratory animals.

    Science.gov (United States)

    Hagenauer, Megan Hastings; Lee, Theresa M

    2013-07-01

    This article is part of a Special Issue "Puberty and Adolescence". One of the defining characteristics of adolescence in humans is a large shift in the timing and structure of sleep. Some of these changes are easily observable at the behavioral level, such as a shift in sleep patterns from a relatively morning to a relatively evening chronotype. However, there are equally large changes in the underlying architecture of sleep, including a >60% decrease in slow brain wave activity, which may reflect cortical pruning. In this review we examine the developmental forces driving adolescent sleep patterns using a cross-species comparison. We find that behavioral and physiological sleep parameters change during adolescence in non-human mammalian species, ranging from primates to rodents, in a manner that is often hormone-dependent. However, the overt appearance of these changes is species-specific, with polyphasic sleepers, such as rodents, showing a phase-advance in sleep timing and consolidation of daily sleep/wake rhythms. Using the classic two-process model of sleep regulation, we demonstrate via a series of simulations that many of the species-specific characteristics of adolescent sleep patterns can be explained by a universal decrease in the build-up and dissipation of sleep pressure. Moreover, and counterintuitively, we find that these changes do not necessitate a large decrease in overall sleep need, fitting the adolescent sleep literature. We compare these results to our previous review detailing evidence for adolescent changes in the regulation of sleep by the circadian timekeeping system (Hagenauer and Lee, 2012), and suggest that both processes may be responsible for adolescent sleep patterns. Published by Elsevier Inc.

  16. The role of sleep in human declarative memory consolidation.

    Science.gov (United States)

    Alger, Sara E; Chambers, Alexis M; Cunningham, Tony; Payne, Jessica D

    2015-01-01

    Through a variety of methods, researchers have begun unraveling the mystery of why humans spend one-third of their lives asleep. Though sleep likely serves multiple functions, it has become clear that the sleeping brain offers an ideal environment for solidifying newly learned information in the brain. Sleep , which comprises a complex collection of brain states, supports the consolidation of many different types of information. It not only promotes learning and memory stabilization, but also memory reorganization that can lead to various forms of insightful behavior. As this chapter will describe, research provides ample support for these crucial cognitive functions of sleep . Focusing on the declarative memory system in humans, we review the literature regarding the benefits of sleep for both neutral and emotionally salient declarative memory. Finally, we discuss the literature regarding the impact of sleep on emotion regulation.

  17. Circadian and homeostatic sleep regulation in humans : effects of age and monochromatic light

    OpenAIRE

    Münch, Mirjam

    2006-01-01

    The first part of this thesis deals with age-related modifications in the circadian and homeostatic sleep regulation, whereas in the second part, the effects of an evening exposure to monochromatic light on subsequent sleep architecture and sleep electroencephalographic power spectra are described. Age and sleep Sleep in humans undergoes several age-related changes, resulting in less consolidated sleep, reduced slow wave sleep, advanced sleep-wake timing and shorter noctu...

  18. Adolescent sleep patterns in humans and laboratory animals

    OpenAIRE

    Hagenauer, Megan Hastings; Lee, Theresa M

    2013-01-01

    One of the defining characteristics of adolescence in humans is a large shift in the timing and structure of sleep. Some of these changes are easily observable at the behavioral level, such as a shift in sleep patterns from a relatively morning to a relatively evening chronotype. However, there are equally large changes in the underlying architecture of sleep, including a > 60% decrease in slow brain wave activity, which may reflect cortical pruning. In this review we examine the developmenta...

  19. Sleep

    Science.gov (United States)

    ... REM sleep? What is the effect of sleep deprivation? What are sleep myths? What are sleep disorders? ... Some hormones produced during sleep affect the body's use of energy. This may be how inadequate sleep ...

  20. Evidence that the lunar cycle influences human sleep.

    Science.gov (United States)

    Cajochen, Christian; Altanay-Ekici, Songül; Münch, Mirjam; Frey, Sylvia; Knoblauch, Vera; Wirz-Justice, Anna

    2013-08-05

    Endogenous rhythms of circalunar periodicity (∼29.5 days) and their underlying molecular and genetic basis have been demonstrated in a number of marine species [1, 2]. In contrast, there is a great deal of folklore but no consistent association of moon cycles with human physiology and behavior [3]. Here we show that subjective and objective measures of sleep vary according to lunar phase and thus may reflect circalunar rhythmicity in humans. To exclude confounders such as increased light at night or the potential bias in perception regarding a lunar influence on sleep, we retrospectively analyzed sleep structure, electroencephalographic activity during non-rapid-eye-movement (NREM) sleep, and secretion of the hormones melatonin and cortisol found under stringently controlled laboratory conditions in a cross-sectional setting. At no point during and after the study were volunteers or investigators aware of the a posteriori analysis relative to lunar phase. We found that around full moon, electroencephalogram (EEG) delta activity during NREM sleep, an indicator of deep sleep, decreased by 30%, time to fall asleep increased by 5 min, and EEG-assessed total sleep duration was reduced by 20 min. These changes were associated with a decrease in subjective sleep quality and diminished endogenous melatonin levels. This is the first reliable evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Declarative Memory Consolidation: Mechanisms Acting during Human Sleep

    Science.gov (United States)

    Gais, Steffen; Born, Jan

    2004-01-01

    Of late, an increasing number of studies have shown a strong relationship between sleep and memory. Here we summarize a series of our own studies in humans supporting a beneficial influence of slow-wave sleep (SWS) on declarative memory formation, and try to identify some mechanisms that might underlie this influence. Specifically, these…

  2. Defining and determining the properties of the human sleep homeostat

    NARCIS (Netherlands)

    Zavada, Andrei

    2007-01-01

    To summarize, the principal findings upon which this thesis is built, are these: 1. The most accurate measure of the human chronotype on the 24-h scale relative to external time is the timepoint at a point in the 30–40% range of habitual sleep length on free days. 2. The free-day mid-sleep time

  3. Effect of sleep deprivation on the human metabolome

    NARCIS (Netherlands)

    S.K. Davies (Sarah); J.E. Ang (Joo Ern); V.L. Revell (Victoria); B. Holmes (Ben); A. Mann (Anuska); F.P. Robertson (Francesca); N. Cui (Nanyi); B. Middleton (Benita); K. Ackermann (Katrin); M.H. Kayser (Manfred); A.E. Thumser (Alfred); P. Raynaud (Philippe); D.J. Skene (Debra)

    2014-01-01

    textabstractSleep restriction and circadian clock disruption are associated with metabolic disorders such as obesity, insulin resistance, and diabetes. The metabolic pathways involved in human sleep, however, have yet to be investigatedwith the use of a metabolomics approach. Here we have used

  4. Circadian and Wakefulness-Sleep Modulation of Cognition in Humans

    Directory of Open Access Journals (Sweden)

    Kenneth P Wright

    2012-04-01

    Full Text Available Cognitive and affective processes vary over the course of the 24 hour day. Time of day dependent changes in human cognition are modulated by an internal circadian timekeeping system with a near-24-hour period. The human circadian timekeeping system interacts with sleep-wakefulness regulatory processes to modulate brain arousal, neurocognitive and affective function. Brain arousal is regulated by ascending brain stem, basal forebrain and hypothalamic arousal systems and inhibition or disruption of these systems reduces brain arousal, impairs cognition, and promotes sleep. The internal circadian timekeeping system modulates cognition and affective function by projections from the master circadian clock, located in the hypothalamic suprachiasmatic nuclei, to arousal and sleep systems and via clock gene oscillations in brain tissues. Understanding the basic principles of circadian and wakefulness-sleep physiology can help to recognize how the circadian system modulates human cognition and influences learning, memory and emotion. Developmental changes in sleep and circadian processes and circadian misalignment in circadian rhythm sleep disorders have important implications for learning, memory and emotion. Overall, when wakefulness occurs at appropriate internal biological times, circadian clockwork benefits human cognitive and emotion function throughout the lifespan. Yet, when wakefulness occurs at inappropriate biological times because of environmental pressures (e.g., early school start times, long work hours that include work at night, shift work, jet lag or because of circadian rhythm sleep disorders, the resulting misalignment between circadian and wakefulness-sleep physiology leads to impaired cognitive performance, learning, emotion, and safety.

  5. The sleep-deprived human brain.

    Science.gov (United States)

    Krause, Adam J; Simon, Eti Ben; Mander, Bryce A; Greer, Stephanie M; Saletin, Jared M; Goldstein-Piekarski, Andrea N; Walker, Matthew P

    2017-07-01

    How does a lack of sleep affect our brains? In contrast to the benefits of sleep, frameworks exploring the impact of sleep loss are relatively lacking. Importantly, the effects of sleep deprivation (SD) do not simply reflect the absence of sleep and the benefits attributed to it; rather, they reflect the consequences of several additional factors, including extended wakefulness. With a focus on neuroimaging studies, we review the consequences of SD on attention and working memory, positive and negative emotion, and hippocampal learning. We explore how this evidence informs our mechanistic understanding of the known changes in cognition and emotion associated with SD, and the insights it provides regarding clinical conditions associated with sleep disruption.

  6. [The neuropathology of sleep in human neurodegenerative diseases].

    Science.gov (United States)

    Hauw, J-J; Hausser-Hauw, C; Hasboun, D; Seilhean, D

    2008-01-01

    The neuropathology of human sleep remains an ill-defined issue. The data concerning the main structures of human brain areas involved, or supposed to be implicated, in sleep organisation are reviewed. Five levels of organisation can be schematically recognized: (i) the ascending arousal system, (ii) the non REM and REM systems (iii) regulated by hypothalamic areas, (iv) and the biological clock, (v) modulated by a number of "allostatic" influences. These are briefly described, with emphasis on the location of structures involved in humans, and on the recently revised concepts. Current knowledge on the topography of lesions associated with the main sleep disorders in degenerative diseases is recalled, including REM sleep behavior disorders, restless legs syndrome and periodic leg movements, sleep apneas, insomnia, excessive daily sleepiness, secondary narcolepsy and disturbed sleep-wake rhythms. The lesions of sleep related structures observed in early and late stages of four degenerative diseases are then reviewed. Two synucleinopathies (Lewy lesions associated disorders, including Parkinson's disease and Dementia with Lewy bodies, and Multiple System Atrophy) and two tauopathies (Progressive Supranuclear Palsy and Alzheimer's disease) are dealt with. The distribution of lesions usually found in affected patients fit with that expected from the prevalence of different sleep disorders in these diseases. This confirms the current opinion that these disorders depend on the distribution of lesions rather than on their biochemical nature. Further studies might throw insight on the mechanism of normal and pathological sleep in humans, counterpart of the increasing knowledge provided by animal models. Specially designed prospective clinicopathological studies including peculiar attention to sleep are urgently needed.

  7. Hippocampal sleep features: relations to human memory function.

    Science.gov (United States)

    Ferrara, Michele; Moroni, Fabio; De Gennaro, Luigi; Nobili, Lino

    2012-01-01

    The recent spread of intracranial electroencephalographic (EEG) recording techniques for presurgical evaluation of drug-resistant epileptic patients is providing new information on the activity of different brain structures during both wakefulness and sleep. The interest has been mainly focused on the medial temporal lobe, and in particular the hippocampal formation, whose peculiar local sleep features have been recently described, providing support to the idea that sleep is not a spatially global phenomenon. The study of the hippocampal sleep electrophysiology is particularly interesting because of its central role in the declarative memory formation. Recent data indicate that sleep contributes to memory formation. Therefore, it is relevant to understand whether specific patterns of activity taking place during sleep are related to memory consolidation processes. Fascinating similarities between different states of consciousness (wakefulness, REM sleep, non-REM sleep) in some electrophysiological mechanisms underlying cognitive processes have been reported. For instance, large-scale synchrony in gamma activity is important for waking memory and perception processes, and its changes during sleep may be the neurophysiological substrate of sleep-related deficits of declarative memory. Hippocampal activity seems to specifically support memory consolidation during sleep, through specific coordinated neurophysiological events (slow waves, spindles, ripples) that would facilitate the integration of new information into the pre-existing cortical networks. A few studies indeed provided direct evidence that rhinal ripples as well as slow hippocampal oscillations are correlated with memory consolidation in humans. More detailed electrophysiological investigations assessing the specific relations between different types of memory consolidation and hippocampal EEG features are in order. These studies will add an important piece of knowledge to the elucidation of the ultimate

  8. Sleep in the human hippocampus: a stereo-EEG study.

    Directory of Open Access Journals (Sweden)

    Fabio Moroni

    Full Text Available BACKGROUND: There is compelling evidence indicating that sleep plays a crucial role in the consolidation of new declarative, hippocampus-dependent memories. Given the increasing interest in the spatiotemporal relationships between cortical and hippocampal activity during sleep, this study aimed to shed more light on the basic features of human sleep in the hippocampus. METHODOLOGY/PRINCIPAL FINDINGS: We recorded intracerebral stereo-EEG directly from the hippocampus and neocortical sites in five epileptic patients undergoing presurgical evaluations. The time course of classical EEG frequency bands during the first three NREM-REM sleep cycles of the night was evaluated. We found that delta power shows, also in the hippocampus, the progressive decrease across sleep cycles, indicating that a form of homeostatic regulation of delta activity is present also in this subcortical structure. Hippocampal sleep was also characterized by: i a lower relative power in the slow oscillation range during NREM sleep compared to the scalp EEG; ii a flattening of the time course of the very low frequencies (up to 1 Hz across sleep cycles, with relatively high levels of power even during REM sleep; iii a decrease of power in the beta band during REM sleep, at odds with the typical increase of power in the cortical recordings. CONCLUSIONS/SIGNIFICANCE: Our data imply that cortical slow oscillation is attenuated in the hippocampal structures during NREM sleep. The most peculiar feature of hippocampal sleep is the increased synchronization of the EEG rhythms during REM periods. This state of resonance may have a supportive role for the processing/consolidation of memory.

  9. Hippocampal sleep features: relations to human memory function

    Directory of Open Access Journals (Sweden)

    Michele eFerrara

    2012-04-01

    Full Text Available The recent spread of intracranial EEG recordings techniques for presurgical evaluation of drug-resistant epileptic patients is providing new information on the activity of different brain structures during both wakefulness and sleep. The interest has been mainly focused on the medial temporal lobe, and in particular the hippocampal formation, whose peculiar local sleep features have been recently described, providing support to the idea that sleep is not a spatially global phenomenon. The study of the hippocampal sleep electrophysiology is particularly interesting because of its central role in the declarative memory formation. Recent data indicate that sleep contributes to memory formation. Therefore, it is relevant to understand whether specific pattern of activity taking place during sleep are related to memory consolidation processes. Fascinating similarities between different states of consciousness (wakefulness, REM sleep, NREM sleep in some electrophysiological mechanisms underlying cognitive processes have been reported. For instance, large-scale synchrony in gamma activity is important for waking memory and perception processes, and its changes during sleep may be the neurophysiological substrate of sleep-related deficits of declarative memory. Hippocampal activity seems to specifically support memory consolidation during sleep, through specific coordinated neurophysiological events (slow waves, spindles, ripples that would facilitate the integration of new information into the pre-existing cortical networks. A few studies indeed provided direct evidence that rhinal ripples as well as slow hippocampal oscillations are correlated with memory consolidation in humans. More detailed electrophysiological investigations assessing the specific relations between different types of memory consolidation and hippocampal EEG features are in order. These studies will add an important piece of knowledge to the elucidation of the ultimate sleep

  10. The ontogeny of sleep-wake cycles in zebrafish: a comparison to humans

    OpenAIRE

    Amanda eSorribes; Haraldur eÞorsteinsson; Hrönn eArnardóttir; Ingibjörg H Jóhannesdóttir; Benjamín eSigurgeirsson; Gonzalo G de Polavieja; Karlsson, Karl Æ.

    2013-01-01

    Zebrafish (Danio rerio) are used extensively in sleep research; both to further understanding of sleep in general and also as a model of human sleep. To date, sleep studies have been performed in larval and adult zebrafish but no efforts have been made to document the ontogeny of zebrafish sleep-wake cycles. Because sleep differs across phylogeny and ontogeny it is important to validate the use of zebrafish in elucidating the neural substrates of sleep. Here we describe the development of sl...

  11. [Effects of sleep deprivation on human performance].

    Science.gov (United States)

    Fu, Z J; Ma, R S

    2000-08-01

    Objective. To investigate the effects of sleep deprivation (SD) on human performance. Method. 8 healthy male college students participated the test. During 26 h of continuous awakeness (from 6:00 to 8:00 the next day), the volunteers were demanded to perform a battery of tests at 9 different time (7:00, 12:00, 16:00, 20:00, 0:00, 2:00, 4:00, 6:00, 8:00). The tests include: (1) single task: aural Oddball response, the response time (RT1) and correct rate (CR1) were recorded; (2) dual tasks: manual tracking and aural Oddball response, the response time (RT2), tracking error (ER) and correct rate (CR2) were recorded; (3) The Stanford sleepiness scale and subjective ratings of task difficulty access. Result. SD had significant effects on CT1, CT2 and ER (P=0.0001, P=0.00001, P=0.0004 respectively); SD increased RT1, RT2, ER at night time. SD had significant effects on SR, SSS score (P=0.0001, P=0.0000 respectively); SD increased SR, SSS score at night time. Since the subjects changed their response strategy, CR1 and CR2 were not influenced by SD at night time. Conclusion. SD has significant effects on response time, tracking error, subjective difficulty of cognitive tasks and subjective sleepiness.

  12. A novel BHLHE41 variant is associated with short sleep and resistance to sleep deprivation in humans.

    Science.gov (United States)

    Pellegrino, Renata; Kavakli, Ibrahim Halil; Goel, Namni; Cardinale, Christopher J; Dinges, David F; Kuna, Samuel T; Maislin, Greg; Van Dongen, Hans P A; Tufik, Sergio; Hogenesch, John B; Hakonarson, Hakon; Pack, Allan I

    2014-08-01

    Earlier work described a mutation in DEC2 also known as BHLHE41 (basic helix-loophelix family member e41) as causal in a family of short sleepers, who needed just 6 h sleep per night. We evaluated whether there were other variants of this gene in two well-phenotyped cohorts. Sequencing of the BHLHE41 gene, electroencephalographic data, and delta power analysis and functional studies using cell-based luciferase. We identified new variants of the BHLHE41 gene in two cohorts who had either acute sleep deprivation (n = 200) or chronic partial sleep deprivation (n = 217). One variant, Y362H, at another location in the same exon occurred in one twin in a dizygotic twin pair and was associated with reduced sleep duration, less recovery sleep following sleep deprivation, and fewer performance lapses during sleep deprivation than the homozygous twin. Both twins had almost identical amounts of non rapid eye movement (NREM) sleep. This variant reduced the ability of BHLHE41 to suppress CLOCK/BMAL1 and NPAS2/BMAL1 transactivation in vitro. Another variant in the same exome had no effect on sleep or response to sleep deprivation and no effect on CLOCK/BMAL1 transactivation. Random mutagenesis identified a number of other variants of BHLHE41 that affect its function. There are a number of mutations of BHLHE41. Mutations reduce total sleep while maintaining NREM sleep and provide resistance to the effects of sleep loss. Mutations that affect sleep also modify the normal inhibition of BHLHE41 of CLOCK/BMAL1 transactivation. Thus, clock mechanisms are likely involved in setting sleep length and the magnitude of sleep homeostasis. Pellegrino R, Kavakli IH, Goel N, Cardinale CJ, Dinges DF, Kuna ST, Maislin G, Van Dongen HP, Tufik S, Hogenesch JB, Hakonarson H, Pack AI. A novel BHLHE41 variant is associated with short sleep and resistance to sleep deprivation in humans. SLEEP 2014;37(8):1327-1336.

  13. Declarative memory consolidation: mechanisms acting during human sleep.

    Science.gov (United States)

    Gais, Steffen; Born, Jan

    2004-01-01

    Of late, an increasing number of studies have shown a strong relationship between sleep and memory. Here we summarize a series of our own studies in humans supporting a beneficial influence of slow-wave sleep (SWS) on declarative memory formation, and try to identify some mechanisms that might underlie this influence. Specifically, these experiments show that declarative memory benefits mainly from sleep periods dominated by SWS, whereas there is no consistent benefit of this memory from periods rich in rapid eye movement (REM) sleep. A main mechanism of declarative memory formation is believed to be the reactivation of newly acquired memory representations in hippocampal networks that stimulates a transfer and integration of these representations into neocortical neuronal networks. Consistent with this model, spindle activity and slow oscillation-related EEG coherence increase during early sleep after intense declarative learning in humans, signs that together point toward a neocortical reprocessing of the learned material. In addition, sleep seems to provide an optimal milieu for declarative memory reprocessing and consolidation by reducing cholinergic activation and the cortisol feedback to the hippocampus during SWS.

  14. Developmental changes in the human sleep EEG during early adolescence.

    Science.gov (United States)

    Tarokh, Leila; Carskadon, Mary A

    2010-06-01

    To use time-frequency analysis to characterize developmental changes in the human sleep electroencephalogram (EEG) across early adolescence. Sleep EEG was recorded when children were 9/10 years old and 1 to 3 years later after sleeping at home on a fixed schedule for at least one week. A 4-bed sleep laboratory. Fourteen (5 girls) healthy children ages 9/10 (mean = 10.13, SD = +/- 0.51) years at initial and 11 to 13 (mean = 12.28, SD = +/- 0.62) years at follow-up. N/A. All-night polysomnography was performed at each assessment and sleep stages were scored with Rechtschaffen and Kales criteria. Slow wave sleep minutes decreased from the initial to the follow-up session by 29%, while minutes of stage 2 increased by 17%. NREM and REM sleep EEG spectra from two central and two occipital leads were examined for developmental changes. All-night analyses showed a significant decrease of EEG power from the initial to follow-up session across a range of frequencies during NREM and REM sleep. This decline occurred across leads and states in the delta/theta bands (3.8 - 7 Hz). Time-frequency analyses indicated that this effect was consistent across the night. The decline in power with age was most pronounced in the left central and right occipital leads. The frequency of greatest power in the sigma band (11 - 16 Hz) was significantly higher at follow-up. This longitudinal analysis highlights asymmetrical frequency-specific declines in sleep EEG spectral power with early adolescent maturation, which may reflect early signs of the cortical synaptic pruning in the healthy adolescent.

  15. Experimental sleep restriction causes endothelial dysfunction in healthy humans.

    Science.gov (United States)

    Calvin, Andrew D; Covassin, Naima; Kremers, Walter K; Adachi, Taro; Macedo, Paula; Albuquerque, Felipe N; Bukartyk, Jan; Davison, Diane E; Levine, James A; Singh, Prachi; Wang, Shihan; Somers, Virend K

    2014-11-25

    Epidemiologic evidence suggests a link between short sleep duration and cardiovascular risk, although the nature of any relationship and mechanisms remain unclear. Short sleep duration has also been linked to an increase in cardiovascular events. Endothelial dysfunction has itself been implicated as a mediator of heightened cardiovascular risk. We sought to determine the effect of 8 days/8 nights of partial sleep restriction on endothelial function in healthy humans. Sixteen healthy volunteers underwent a randomized study of usual sleep versus sleep restriction of two-thirds normal sleep time for 8 days/8 nights in a hospital-based clinical research unit. The main outcome was endothelial function measured by flow-mediated brachial artery vasodilatation (FMD). Those randomized to sleep restriction slept 5.1 hours/night during the experimental period compared with 6.9 hours/night in the control group. Sleep restriction was associated with significant impairment in FMD (8.6±4.6% during the initial pre-randomization acclimation phase versus 5.2±3.4% during the randomized experimental phase, P=0.01) whereas no change was seen in the control group (5.0±3.0 during the acclimation phase versus 6.73±2.9% during the experimental phase, P=0.10) for a between-groups difference of -4.40% (95% CI -7.00 to -1.81%, P=0.003). No change was seen in non-flow mediated vasodilatation (NFMD) in either group. In healthy individuals, moderate sleep restriction causes endothelial dysfunction. ClinicalTrials.gov. Unique identifier: NCT01334788. © 2014 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  16. Learning increases human electroencephalographic coherence during subsequent slow sleep oscillations.

    Science.gov (United States)

    Mölle, Matthias; Marshall, Lisa; Gais, Steffen; Born, Jan

    2004-09-21

    Learning is assumed to induce specific changes in neuronal activity during sleep that serve the consolidation of newly acquired memories. To specify such changes, we measured electroencephalographic (EEG) coherence during performance on a declarative learning task (word pair associations) and subsequent sleep. Compared with a nonlearning control condition, learning performance was accompanied with a strong increase in coherence in several EEG frequency bands. During subsequent non-rapid eye movement sleep, coherence only marginally increased in a global analysis of EEG recordings. However, a striking and robust increase in learning-dependent coherence was found when analyses were performed time-locked to the occurrence of slow oscillations (learning in the slow-oscillatory, delta, slow-spindle, and gamma bands. The findings identify the depolarizing phase of the slow oscillations in humans as a time period particularly relevant for a reprocessing of memories in sleep.

  17. Combining Human Epigenetics and Sleep Studies in Caenorhabditis elegans: A Cross-Species Approach for Finding Conserved Genes Regulating Sleep.

    Science.gov (United States)

    Huang, Huiyan; Zhu, Yong; Eliot, Melissa N; Knopik, Valerie S; McGeary, John E; Carskadon, Mary A; Hart, Anne C

    2017-06-01

    We aimed to test a combined approach to identify conserved genes regulating sleep and to explore the association between DNA methylation and sleep length. We identified candidate genes associated with shorter versus longer sleep duration in college students based on DNA methylation using Illumina Infinium HumanMethylation450 BeadChip arrays. Orthologous genes in Caenorhabditis elegans were identified, and we examined whether their loss of function affected C. elegans sleep. For genes whose perturbation affected C. elegans sleep, we subsequently undertook a small pilot study to re-examine DNA methylation in an independent set of human participants with shorter versus longer sleep durations. Eighty-seven out of 485,577 CpG sites had significant differential methylation in young adults with shorter versus longer sleep duration, corresponding to 52 candidate genes. We identified 34 C. elegans orthologs, including NPY/flp-18 and flp-21, which are known to affect sleep. Loss of five additional genes alters developmentally timed C. elegans sleep (B4GALT6/bre-4, DOCK180/ced-5, GNB2L1/rack-1, PTPRN2/ida-1, ZFYVE28/lst-2). For one of these genes, ZFYVE28 (also known as hLst2), the pilot replication study again found decreased DNA methylation associated with shorter sleep duration at the same two CpG sites in the first intron of ZFYVE28. Using an approach that combines human epigenetics and C. elegans sleep studies, we identified five genes that play previously unidentified roles in C. elegans sleep. We suggest sleep duration in humans may be associated with differential DNA methylation at specific sites and that the conserved genes identified here likely play roles in C. elegans sleep and in other species.

  18. Sleep-dependent motor memory plasticity in the human brain.

    Science.gov (United States)

    Walker, M P; Stickgold, R; Alsop, D; Gaab, N; Schlaug, G

    2005-01-01

    Growing evidence indicates a role for sleep in off-line memory processing, specifically in post-training consolidation. In humans, sleep has been shown to trigger overnight learning on a motor-sequence memory task, while equivalent waking periods produce no such improvement. But while the behavioral characteristics of sleep-dependent motor learning become increasingly well characterized, the underlying neural basis remains unknown. Here we present functional magnetic resonance imaging data demonstrating a change in the representation of a motor memory after a night of sleep. Subjects trained on a motor-skill memory and 12 hours later, after either sleep or wake, were retested during functional magnetic resonance imaging. Following sleep relative to wake, regions of increased activation were expressed in the right primary motor cortex, medial prefrontal lobe, hippocampus and left cerebellum; changes that can support faster motor output and more precise mapping of key-press movements. In contrast, signal decreases were identified in parietal cortices, the left insular cortex, temporal pole and fronto-polar region, reflecting a reduced need for conscious spatial monitoring and a decreased emotional task burden. This evidence of an overnight, systems-level change in the representation of a motor memory holds important implications for acquiring real-life skills and in clinical rehabilitation following brain trauma, such as stroke.

  19. Timing of human sleep : recovery process gated by a circadian pacemaker

    NARCIS (Netherlands)

    DAAN, S; BEERSMA, DGM; BORBELY, AA

    1984-01-01

    A model for the timing of human sleep is presented, It is based on a sleep-regulating variable (S)-possibly, but not necessarily, associated with a neurochemical substance-which increases during wakefulness and decreases during sleep. Sleep onset is triggered when S approaches an upper threshold

  20. The ontogeny of sleep-wake cycles in zebrafish: a comparison to humans

    Directory of Open Access Journals (Sweden)

    Amanda eSorribes

    2013-11-01

    Full Text Available Zebrafish (Danio rerio are used extensively in sleep research; both to further understanding of sleep in general and also as a model of human sleep. To date, sleep studies have been performed in larval and adult zebrafish but no efforts have been made to document the ontogeny of zebrafish sleep-wake cycles. Because sleep differs across phylogeny and ontogeny it is important to validate the use of zebrafish in elucidating the neural substrates of sleep. Here we describe the development of sleep and wake across the zebrafish lifespan and how it compares to humans. We find power-law distributions to best fit wake-bout data but demonstrate that exponential distributions, previously used to describe sleep bout distributions, fail to adequately account for the data in either species. Regardless, the data reveal remarkable similarities in the ontogeny of sleep cycles in zebrafish and humans. Moreover, as seen in other organisms, zebrafish sleep levels are highest early in ontogeny and sleep and wake bouts gradually consolidate to form the adult sleep pattern. Finally, sleep percentage, bout duration, bout number and sleep fragmentation are shown to allow for meaningful comparisons between zebrafish and human sleep.

  1. Telomere length is associated with sleep duration but not sleep quality in adults with human immunodeficiency virus.

    Science.gov (United States)

    Lee, Kathryn A; Gay, Caryl; Humphreys, Janice; Portillo, Carmen J; Pullinger, Clive R; Aouizerat, Bradley E

    2014-01-01

    Telomere length provides an estimate of cellular aging and is influenced by oxidative stress and health behaviors such as diet and exercise. This article describes relationships between telomere length and sleep parameters that included total sleep time (TST), wake after sleep onset (WASO), and self-reported sleep quality in a sample of adults with chronic illness. Cross-sectional study of 283 adults (74% male, 42% Caucasian) infected with human immunodeficiency virus (HIV) while living in the San Francisco Bay area, CA, USA. Ages ranged from 22-77 y. TST and WASO were estimated with wrist actigraphy across 72 h; self-reported sleep quality was assessed with the Pittsburgh Sleep Quality Index. Relative telomere length (RTL) in leukocytes was estimated by quantitative polymerase chain reaction assays. Shorter RTL was associated with older age, and RTL was shorter in males than females. RTL was unrelated to HIV disease characteristics. RTL was not associated with WASO or self-reported sleep quality. Participants with at least 7 h sleep had longer RTL than those with less than 7 h, even after controlling for the effects of age, sex, race, education, body mass index, metabolic hormones (i.e., leptin, ghrelin, adiponectin, and resistin), depression and anxiety, and sleep quality. Results suggest that sleep duration is associated with preserving telomere length in a population of human immunodeficiency virus-infected adults. Getting at least 7 hours of sleep at night may either protect telomeres from damage or restore them on a nightly basis.

  2. Selective neuronal lapses precede human cognitive lapses following sleep deprivation.

    Science.gov (United States)

    Nir, Yuval; Andrillon, Thomas; Marmelshtein, Amit; Suthana, Nanthia; Cirelli, Chiara; Tononi, Giulio; Fried, Itzhak

    2017-12-01

    Sleep deprivation is a major source of morbidity with widespread health effects, including increased risk of hypertension, diabetes, obesity, heart attack, and stroke. Moreover, sleep deprivation brings about vehicle accidents and medical errors and is therefore an urgent topic of investigation. During sleep deprivation, homeostatic and circadian processes interact to build up sleep pressure, which results in slow behavioral performance (cognitive lapses) typically attributed to attentional thalamic and frontoparietal circuits, but the underlying mechanisms remain unclear. Recently, through study of electroencephalograms (EEGs) in humans and local field potentials (LFPs) in nonhuman primates and rodents it was found that, during sleep deprivation, regional 'sleep-like' slow and theta (slow/theta) waves co-occur with impaired behavioral performance during wakefulness. Here we used intracranial electrodes to record single-neuron activities and LFPs in human neurosurgical patients performing a face/nonface categorization psychomotor vigilance task (PVT) over multiple experimental sessions, including a session after full-night sleep deprivation. We find that, just before cognitive lapses, the selective spiking responses of individual neurons in the medial temporal lobe (MTL) are attenuated, delayed, and lengthened. These 'neuronal lapses' are evident on a trial-by-trial basis when comparing the slowest behavioral PVT reaction times to the fastest. Furthermore, during cognitive lapses, LFPs exhibit a relative local increase in slow/theta activity that is correlated with degraded single-neuron responses and with baseline theta activity. Our results show that cognitive lapses involve local state-dependent changes in neuronal activity already present in the MTL.

  3. Effects of an interleukin-1 receptor antagonist on human sleep, sleep-associated memory consolidation, and blood monocytes.

    Science.gov (United States)

    Schmidt, Eva-Maria; Linz, Barbara; Diekelmann, Susanne; Besedovsky, Luciana; Lange, Tanja; Born, Jan

    2015-07-01

    Pro-inflammatory cytokines like interleukin-1 beta (IL-1) are major players in the interaction between the immune system and the central nervous system. Various animal studies report a sleep-promoting effect of IL-1 leading to enhanced slow wave sleep (SWS). Moreover, this cytokine was shown to affect hippocampus-dependent memory. However, the role of IL-1 in human sleep and memory is not yet understood. We administered the synthetic IL-1 receptor antagonist anakinra (IL-1ra) in healthy humans (100mg, subcutaneously, before sleep; n=16) to investigate the role of IL-1 signaling in sleep regulation and sleep-dependent declarative memory consolidation. Inasmuch monocytes have been considered a model for central nervous microglia, we monitored cytokine production in classical and non-classical blood monocytes to gain clues about how central nervous effects of IL-1ra are conveyed. Contrary to our expectation, IL-1ra increased EEG slow wave activity during SWS and non-rapid eye movement (NonREM) sleep, indicating a deepening of sleep, while sleep-associated memory consolidation remained unchanged. Moreover, IL-1ra slightly increased prolactin and reduced cortisol levels during sleep. Production of IL-1 by classical monocytes was diminished after IL-1ra. The discrepancy to findings in animal studies might reflect species differences and underlines the importance of studying cytokine effects in humans. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  4. Circadian regulation of human sleep and age-related changes in its timing, consolidation and EEG characteristics

    Science.gov (United States)

    Dijk, D. J.; Duffy, J. F.

    1999-01-01

    The light-entrainable circadian pacemaker located in the suprachiasmatic nucleus of the hypothalamus regulates the timing and consolidation of sleep by generating a paradoxical rhythm of sleep propensity; the circadian drive for wakefulness peaks at the end of the day spent awake, ie close to the onset of melatonin secretion at 21.00-22.00 h and the circadian drive for sleep crests shortly before habitual waking-up time. With advancing age, ie after early adulthood, sleep consolidation declines, and time of awakening and the rhythms of body temperature, plasma melatonin and cortisol shift to an earlier clock hour. The variability of the phase relationship between the sleep-wake cycle and circadian rhythms increases, and in old age sleep is more susceptible to internal arousing stimuli associated with circadian misalignment. The propensity to awaken from sleep advances relative to the body temperature nadir in older people, a change that is opposite to the phase delay of awakening relative to internal circadian rhythms associated with morningness in young people. Age-related changes do not appear to be associated with a shortening of the circadian period or a reduction of the circadian drive for wake maintenance. These changes may be related to changes in the sleep process itself, such as reductions in slow-wave sleep and sleep spindles as well as a reduced strength of the circadian signal promoting sleep in the early morning hours. Putative mediators and modulators of circadian sleep regulation are discussed.

  5. Apnea-Induced Rapid Eye Movement Sleep Disruption Impairs Human Spatial Navigational Memory

    OpenAIRE

    Varga, Andrew W.; Kishi, Akifumi; Mantua, Janna; Lim, Jason; Koushyk, Viachaslau; Leibert, David P.; Osorio, Ricardo S.; Rapoport, David M.; Ayappa, Indu

    2014-01-01

    Hippocampal electrophysiology and behavioral evidence support a role for sleep in spatial navigational memory, but the role of particular sleep stages is less clear. Although rodent models suggest the importance of rapid eye movement (REM) sleep in spatial navigational memory, a similar role for REM sleep has never been examined in humans. We recruited subjects with severe obstructive sleep apnea (OSA) who were well treated and adherent with continuous positive airway pressure (CPAP). Restric...

  6. Effects of Extreme Sleep Deprivation on Human Performance

    Energy Technology Data Exchange (ETDEWEB)

    Tuan Tran; Kimberly R. Raddatz; Elizabeth T. Cady; Bradford Amstutz; Pete D. Elgin; Christopher Vowels; Gerald Deehan

    2007-04-01

    Sleep is a fundamental recuperative process for the nervous system. Disruption of this homeostatic drive can lead to severe impairments of the operator’s ability to perceive, recognize, and respond to emergencies and/or unanticipated events, putting the operator at risk. Therefore, establishing a comprehensive understanding of how sleep deprivation influences human performance is essential in order to counter fatigue or to develop mitigation strategies. The goal of the present study was to examine the psychological effects of prolonged sleep deprivation (approx. 75 hrs) over a four-day span on a general aviation pilot flying a fixed-based flight simulator. During the study, a series of tasks were employed every four hours in order to examine the pilot’s perceptual and higher level cognitive abilities. Overall, results suggest that the majority of cognitive and perceptual degradation occurs between 30-40 hours into the flight. Limitations and future research directions are also discussed.

  7. Human turnover dynamics during sleep: Statistical behavior and its modeling

    Science.gov (United States)

    Yoneyama, Mitsuru; Okuma, Yasuyuki; Utsumi, Hiroya; Terashi, Hiroo; Mitoma, Hiroshi

    2014-03-01

    Turnover is a typical intermittent body movement while asleep. Exploring its behavior may provide insights into the mechanisms and management of sleep. However, little is understood about the dynamic nature of turnover in healthy humans and how it can be modified in disease. Here we present a detailed analysis of turnover signals that are collected by accelerometry from healthy elderly subjects and age-matched patients with neurodegenerative disorders such as Parkinson's disease. In healthy subjects, the time intervals between consecutive turnover events exhibit a well-separated bimodal distribution with one mode at ⩽10 s and the other at ⩾100 s, whereas such bimodality tends to disappear in neurodegenerative patients. The discovery of bimodality and fine temporal structures (⩽10 s) is a contribution that is not revealed by conventional sleep recordings with less time resolution (≈30 s). Moreover, we estimate the scaling exponent of the interval fluctuations, which also shows a clear difference between healthy subjects and patients. We incorporate these experimental results into a computational model of human decision making. A decision is to be made at each simulation step between two choices: to keep on sleeping or to make a turnover, the selection of which is determined dynamically by comparing a pair of random numbers assigned to each choice. This decision is weighted by a single parameter that reflects the depth of sleep. The resulting simulated behavior accurately replicates many aspects of observed turnover patterns, including the appearance or disappearance of bimodality and leads to several predictions, suggesting that the depth parameter may be useful as a quantitative measure for differentiating between normal and pathological sleep. These findings have significant clinical implications and may pave the way for the development of practical sleep assessment technologies.

  8. A Novel BHLHE41 Variant is Associated with Short Sleep and Resistance to Sleep Deprivation in Humans

    Science.gov (United States)

    Pellegrino, Renata; Kavakli, Ibrahim Halil; Goel, Namni; Cardinale, Christopher J.; Dinges, David F.; Kuna, Samuel T.; Maislin, Greg; Van Dongen, Hans P.A.; Tufik, Sergio; Hogenesch, John B.; Hakonarson, Hakon; Pack, Allan I.

    2014-01-01

    Study Objectives: Earlier work described a mutation in DEC2 also known as BHLHE41 (basic helix-loophelix family member e41) as causal in a family of short sleepers, who needed just 6 h sleep per night. We evaluated whether there were other variants of this gene in two well-phenotyped cohorts. Design: Sequencing of the BHLHE41 gene, electroencephalographic data, and delta power analysis and functional studies using cell-based luciferase. Results: We identified new variants of the BHLHE41 gene in two cohorts who had either acute sleep deprivation (n = 200) or chronic partial sleep deprivation (n = 217). One variant, Y362H, at another location in the same exon occurred in one twin in a dizygotic twin pair and was associated with reduced sleep duration, less recovery sleep following sleep deprivation, and fewer performance lapses during sleep deprivation than the homozygous twin. Both twins had almost identical amounts of non rapid eye movement (NREM) sleep. This variant reduced the ability of BHLHE41 to suppress CLOCK/BMAL1 and NPAS2/BMAL1 transactivation in vitro. Another variant in the same exome had no effect on sleep or response to sleep deprivation and no effect on CLOCK/BMAL1 transactivation. Random mutagenesis identified a number of other variants of BHLHE41 that affect its function. Conclusions: There are a number of mutations of BHLHE41. Mutations reduce total sleep while maintaining NREM sleep and provide resistance to the effects of sleep loss. Mutations that affect sleep also modify the normal inhibition of BHLHE41 of CLOCK/BMAL1 transactivation. Thus, clock mechanisms are likely involved in setting sleep length and the magnitude of sleep homeostasis. Citation: Pellegrino R, Kavakli IH, Goel N, Cardinale CJ, Dinges DF, Kuna ST, Maislin G, Van Dongen HP, Tufik S, Hogenesch JB, Hakonarson H, Pack AI. A novel BHLHE41 variant is associated with short sleep and resistance to sleep deprivation in humans. SLEEP 2014;37(8):1327-1336. PMID:25083013

  9. Human longevity is associated with regular sleep patterns, maintenance of slow wave sleep and favorable lipid profile

    Directory of Open Access Journals (Sweden)

    Diego Robles Mazzotti

    2014-06-01

    Full Text Available Some individuals are able to successfully reach very old ages, reflecting higher adaptation against age-associated effects. Sleep is one of the processes deeply affected by aging; however few studies evaluating sleep in long-lived individuals (aged over 85 have been reported to date. The aim of this study was to characterize the sleep patterns and biochemical profile of oldest old individuals (N=10, age 85-105 years old and compare them to young adults (N=15, age 20-30 years old and older adults (N=13, age 60-70 years old. All subjects underwent full-night polysomnography, one-week of actigraphic recording and peripheral blood collection. Sleep electroencephalogram spectral analysis was also performed. The oldest old individuals showed lower sleep efficiency and REM sleep when compared to the older adults, while stage N3 percentage and delta power were similar across the groups. Oldest old individuals maintained strictly regular sleep-wake schedules and also presented higher HDL-cholesterol and lower triglyceride levels than older adults. The present study revealed novel data regarding specific sleep patterns and maintenance of slow wave sleep in the oldest old group. Taken together with the favorable lipid profile, these results contribute with evidence to the importance of sleep and lipid metabolism regulation in the maintenance of longevity in humans.

  10. [The distribution of sleep and wakefulness in human African trypanosomiasis].

    Science.gov (United States)

    Buguet, A; Bert, J; Tapie, P; Bogui, P; Doua, F; Mouanga, G; Stanghellini, A; Sarda, J; Tabaraud, F; Gati, R

    1994-01-01

    Last century, patients with human African trypanosomiasis were described as sleepy by day and restless by night, and physicians referred to this condition as sleeping sickness. Such a description could have evoked a disturbance of circadian rhythms. However, it is only in 1989 that the first 24-hour recording was performed by our team in Niamey (Niger) in a patient with sleeping sickness. The patient was a Niger-born farm worker who had contracted the disease near Gagnoa (Côte d'Ivoire). Polysomnographic recordings (electroencephalogram, EEG, electrooculogram, electromyogram, electrocardiogram, buccal and nasal airflow, and chest respiratory movements) showed a disappearance of the circadian distribution of sleep and wakefulness, which tended to occur evenly throughout day and night, with a sleep-wake alternation of approximately 80 minutes. Two investigations were conducted thereafter. The first one was done at Daloa (Côte d'Ivoire) in 8 patients who were recorded during two 24-hour periods, with and without hourly blood samples; the second at Brazzaville (Congo) in 10 patients recorded for 24 hours before and after treatment with melarsoprol. All patients were at the stage of early meningoencephalitis. At Daloa, polysomnographic recordings were taken on two 8-channel EEG machines (Alvar Minihuit, and T3-ECEM), as well as on a portable Oxford Medilog 9000 system from the same electrodes. Sleep and wake structure was altered in the most severely sick patient, the EEG trace being loaded with slow waves. Stages 1 and 2, and stages 3 and 4 could not be distinguished from one another. In the other patients, all sleep stages were easily scored. No difference was seen between recordings, regarding blood collection.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. The evolution of human sleep: Technological and cultural innovation associated with sleep-wake regulation among Hadza hunter-gatherers.

    Science.gov (United States)

    Samson, David R; Crittenden, Alyssa N; Mabulla, Ibrahim A; Mabulla, Audax Z P

    2017-12-01

    Sleep is necessary for the survival of all mammalian life. In humans, recent investigations have generated critical data on the relationship between sleep and ecology in small-scale societies. Here, we report the technological and social strategies used to alter sleep environments and influence sleep duration and quality among a population of hunter-gatherers, the Hadza of Tanzania. Specifically, we investigated the effects that grass huts, sound levels, and fire had on sleep. We quantitatively compared thermal stress in outdoor environments to that found inside grass hut domiciles to test whether the huts function as thermoregulated microhabitats during the rainy season. Using physiological equivalent temperature (PET), we found that the grass huts provide sleep sites with less overall variation in thermal stress relative to outside baseline environments. We also investigated ambient acoustic measures of nighttime environments and found that sound significantly covaried with sleep-wake activity, with greater sound levels associating with less sleep. Finally, after controlling for ecological variables previously shown to influence sleep in this population, fire was shown to neither facilitate nor discourage sleep expression. Insofar as data among contemporary sub-tropical foragers can inform our understanding of past lifeways, we interpret our findings as suggesting that after the transition to full time terrestriality, it is likely that early Homo would have had novel opportunities to manipulate its environments in ways that could have significantly improved sleep quality. We further conclude that control over sleep environment would have been essential for migration to higher latitudes away from equatorial Africa. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Impact of physical fitness and daily energy expenditure on sleep efficiency in young and older humans

    NARCIS (Netherlands)

    Oudegeest-Sander, M.H.; Eijsvogels, T.M.H.; Verheggen, R.J.; Poelkens, F.; Hopman, M.T.E.; Jones, H.; Thijssen, D.H.J.

    2013-01-01

    BACKGROUND: Physical activity is known to influence sleep efficiency. Relatively little is known about the relationship between physical activity and sleep efficiency in young and older humans and the impact of exercise training on sleep efficiency in healthy older individuals. OBJECTIVES: To

  13. Apnea-induced rapid eye movement sleep disruption impairs human spatial navigational memory.

    Science.gov (United States)

    Varga, Andrew W; Kishi, Akifumi; Mantua, Janna; Lim, Jason; Koushyk, Viachaslau; Leibert, David P; Osorio, Ricardo S; Rapoport, David M; Ayappa, Indu

    2014-10-29

    Hippocampal electrophysiology and behavioral evidence support a role for sleep in spatial navigational memory, but the role of particular sleep stages is less clear. Although rodent models suggest the importance of rapid eye movement (REM) sleep in spatial navigational memory, a similar role for REM sleep has never been examined in humans. We recruited subjects with severe obstructive sleep apnea (OSA) who were well treated and adherent with continuous positive airway pressure (CPAP). Restricting CPAP withdrawal to REM through real-time monitoring of the polysomnogram provides a novel way of addressing the role of REM sleep in spatial navigational memory with a physiologically relevant stimulus. Individuals spent two different nights in the laboratory, during which subjects performed timed trials before and after sleep on one of two unique 3D spatial mazes. One night of sleep was normally consolidated with use of therapeutic CPAP throughout, whereas on the other night, CPAP was reduced only in REM sleep, allowing REM OSA to recur. REM disruption via this method caused REM sleep reduction and significantly fragmented any remaining REM sleep without affecting total sleep time, sleep efficiency, or slow-wave sleep. We observed improvements in maze performance after a night of normal sleep that were significantly attenuated after a night of REM disruption without changes in psychomotor vigilance. Furthermore, the improvement in maze completion time significantly positively correlated with the mean REM run duration across both sleep conditions. In conclusion, we demonstrate a novel role for REM sleep in human memory formation and highlight a significant cognitive consequence of OSA. Copyright © 2014 the authors 0270-6474/14/3414571-07$15.00/0.

  14. Dynamic coupling between slow waves and sleep spindles during slow wave sleep in humans is modulated by functional pre-sleep activation.

    Science.gov (United States)

    Yordanova, Juliana; Kirov, Roumen; Verleger, Rolf; Kolev, Vasil

    2017-11-03

    Co-existent sleep spindles and slow waves have been viewed as a mechanism for offline information processing. Here we explored if the temporal synchronization between slow waves and spindle activity during slow wave sleep (SWS) in humans was modulated by preceding functional activations during pre-sleep learning. We activated differentially the left and right hemisphere before sleep by using a lateralized variant of serial response time task (SRTT) and verified these inter-hemispheric differences by analysing alpha and beta electroencephalographic (EEG) activities during learning. The stability and timing of coupling between positive and negative phases of slow waves and sleep spindle activity during SWS were quantified. Spindle activity was temporally synchronized with both positive (up-state) and negative (down-state) slow half waves. Synchronization of only the fast spindle activity was laterally asymmetric after learning, corresponding to hemisphere-specific activations before sleep. However, the down state was associated with decoupling, whereas the up-state was associated with increased coupling of fast spindle activity over the pre-activated hemisphere. These observations provide original evidence that (1) the temporal grouping of fast spindles by slow waves is a dynamic property of human SWS modulated by functional pre-sleep activation patterns, and (2) fast spindles synchronized by slow waves are functionally distinct.

  15. Recovery sleep after extended wakefulness restores elevated A1 adenosine receptor availability in the human brain.

    Science.gov (United States)

    Elmenhorst, David; Elmenhorst, Eva-Maria; Hennecke, Eva; Kroll, Tina; Matusch, Andreas; Aeschbach, Daniel; Bauer, Andreas

    2017-04-18

    Adenosine and functional A1 adenosine receptor (A1AR) availability are supposed to mediate sleep-wake regulation and cognitive performance. We hypothesized that cerebral A1AR availability after an extended wake period decreases to a well-rested state after recovery sleep. [(18)F]CPFPX positron emission tomography was used to quantify A1AR availability in 15 healthy male adults after 52 h of sleep deprivation and following 14 h of recovery sleep. Data were additionally compared with A1AR values after 8 h of baseline sleep from an earlier dataset. Polysomnography, cognitive performance, and sleepiness were monitored. Recovery from sleep deprivation was associated with a decrease in A1AR availability in several brain regions, ranging from 11% (insula) to 14% (striatum). A1AR availabilities after recovery did not differ from baseline sleep in the control group. The degree of performance impairment, sleepiness, and homeostatic sleep-pressure response to sleep deprivation correlated negatively with the decrease in A1AR availability. Sleep deprivation resulted in a higher A1AR availability in the human brain. The increase that was observed after 52 h of wakefulness was restored to control levels during a 14-h recovery sleep episode. Individuals with a large increase in A1AR availability were more resilient to sleep-loss effects than those with a subtle increase. This pattern implies that differences in endogenous adenosine and A1AR availability might be causal for individual responses to sleep loss.

  16. Magnetoencephalography demonstrates multiple asynchronous generators during human sleep spindles.

    Science.gov (United States)

    Dehghani, Nima; Cash, Sydney S; Rossetti, Andrea O; Chen, Chih Chuan; Halgren, Eric

    2010-07-01

    Sleep spindles are approximately 1 s bursts of 10-16 Hz activity that occur during stage 2 sleep. Spindles are highly synchronous across the cortex and thalamus in animals, and across the scalp in humans, implying correspondingly widespread and synchronized cortical generators. However, prior studies have noted occasional dissociations of the magnetoencephalogram (MEG) from the EEG during spindles, although detailed studies of this phenomenon have been lacking. We systematically compared high-density MEG and EEG recordings during naturally occurring spindles in healthy humans. As expected, EEG was highly coherent across the scalp, with consistent topography across spindles. In contrast, the simultaneously recorded MEG was not synchronous, but varied strongly in amplitude and phase across locations and spindles. Overall, average coherence between pairs of EEG sensors was approximately 0.7, whereas MEG coherence was approximately 0.3 during spindles. Whereas 2 principle components explained approximately 50% of EEG spindle variance, >15 were required for MEG. Each PCA component for MEG typically involved several widely distributed locations, which were relatively coherent with each other. These results show that, in contrast to current models based on animal experiments, multiple asynchronous neural generators are active during normal human sleep spindles and are visible to MEG. It is possible that these multiple sources may overlap sufficiently in different EEG sensors to appear synchronous. Alternatively, EEG recordings may reflect diffusely distributed synchronous generators that are less visible to MEG. An intriguing possibility is that MEG preferentially records from the focal core thalamocortical system during spindles, and EEG from the distributed matrix system.

  17. Effects of electromagnetic fields emitted from W-CDMA-like mobile phones on sleep in humans.

    Science.gov (United States)

    Nakatani-Enomoto, Setsu; Furubayashi, Toshiaki; Ushiyama, Akira; Groiss, Stefan Jun; Ueshima, Kazumune; Sokejima, Shigeru; Simba, Ally Y; Wake, Kanako; Watanabe, So-ichi; Nishikawa, Masami; Miyawaki, Kaori; Taki, Masao; Ugawa, Yoshikazu

    2013-12-01

    In this study, we investigated subjective and objective effects of mobile phones using a Wideband Code Division Multiple Access (W-CDMA)-like system on human sleep. Subjects were 19 volunteers. Real or sham electromagnetic field (EMF) exposures for 3 h were performed before their usual sleep time on 3 consecutive days. They were exposed to real EMF on the second or third experimental day in a double-blind design. Sleepiness and sleep insufficiency were evaluated the next morning. Polysomnograms were recorded for analyses of the sleep variables and power spectra of electroencephalograms (EEG). No significant differences were observed between the two conditions in subjective feelings. Sleep parameters including sleep stage percentages and EEG power spectra did not differ significantly between real and sham exposures. We conclude that continuous wave EMF exposure for 3 h from a W-CDMA-like system has no detectable effects on human sleep. © 2013 Wiley Periodicals, Inc.

  18. Evidence for cortical structural plasticity in humans after a day of waking and sleep deprivation.

    Science.gov (United States)

    Elvsåshagen, Torbjørn; Zak, Nathalia; Norbom, Linn B; Pedersen, Per Ø; Quraishi, Sophia H; Bjørnerud, Atle; Alnæs, Dag; Doan, Nhat Trung; Malt, Ulrik F; Groote, Inge R; Westlye, Lars T

    2017-08-01

    Sleep is an evolutionarily conserved process required for human health and functioning. Insufficient sleep causes impairments across cognitive domains, and sleep deprivation can have rapid antidepressive effects in mood disorders. However, the neurobiological effects of waking and sleep are not well understood. Recently, animal studies indicated that waking and sleep are associated with substantial cortical structural plasticity. Here, we hypothesized that structural plasticity can be observed after a day of waking and sleep deprivation in the human cerebral cortex. To test this hypothesis, 61 healthy adult males underwent structural magnetic resonance imaging (MRI) at three time points: in the morning after a regular night's sleep, the evening of the same day, and the next morning, either after total sleep deprivation (N=41) or a night of sleep (N=20). We found significantly increased right prefrontal cortical thickness from morning to evening across all participants. In addition, pairwise comparisons in the deprived group between the two morning scans showed significant thinning of mainly bilateral medial parietal cortices after 23h of sleep deprivation, including the precuneus and posterior cingulate cortex. However, there were no significant group (sleep vs. sleep deprived group) by time interactions and we can therefore not rule out that other mechanisms than sleep deprivation per se underlie the bilateral medial parietal cortical thinning observed in the deprived group. Nonetheless, these cortices are thought to subserve wakefulness, are among the brain regions with highest metabolic rate during wake, and are considered some of the most sensitive cortical regions to a variety of insults. Furthermore, greater thinning within the left medial parietal cluster was associated with increased sleepiness after sleep deprivation. Together, these findings add to a growing body of data showing rapid structural plasticity within the human cerebral cortex detectable with

  19. The role of sleep in recovery following ischemic stroke: A review of human and animal data

    Directory of Open Access Journals (Sweden)

    Simone B. Duss

    2017-01-01

    Full Text Available Despite advancements in understanding the pathophysiology of stroke and the state of the art in acute management of afflicted patients as well as in subsequent neurorehabilitation training, stroke remains the most common neurological cause of long-term disability in adulthood. To enhance stroke patients’ independence and well-being it is necessary, therefore, to consider and develop new therapeutic strategies and approaches. We postulate that sleep might play a pivotal role in neurorehabilitation following stroke. Over the last two decades compelling evidence for a major function of sleep in neuroplasticity and neural network reorganization underlying learning and memory has evolved. Training and learning of new motor skills and knowledge can modulate the characteristics of subsequent sleep, which additionally can improve memory performance. While healthy sleep appears to support neuroplasticity resulting in improved learning and memory, disturbed sleep following stroke in animals and humans can impair stroke outcome. In addition, sleep disorders such as sleep disordered breathing, insomnia, and restless legs syndrome are frequent in stroke patients and associated with worse recovery outcomes. Studies investigating the evolution of post-stroke sleep changes suggest that these changes might also reflect neural network reorganization underlying functional recovery. Experimental and clinical studies provide evidence that pharmacological sleep promotion in rodents and treatment of sleep disorders in humans improves functional outcome following stroke. Taken together, there is accumulating evidence that sleep represents a “plasticity state” in the process of recovery following ischemic stroke. However, to test the key role of sleep and sleep disorders for stroke recovery and to better understand the underlying molecular mechanisms, experimental research and large-scale prospective studies in humans are necessary. The effects of hospital

  20. Human Hippocampal Structure: A Novel Biomarker Predicting Mnemonic Vulnerability to, and Recovery from, Sleep Deprivation

    Science.gov (United States)

    Goldstein-Piekarski, Andrea N.; Greer, Stephanie M.; Stark, Shauna; Stark, Craig E.

    2016-01-01

    Sleep deprivation impairs the formation of new memories. However, marked interindividual variability exists in the degree to which sleep loss compromises learning, the mechanistic reasons for which are unclear. Furthermore, which physiological sleep processes restore learning ability following sleep deprivation are similarly unknown. Here, we demonstrate that the structural morphology of human hippocampal subfields represents one factor determining vulnerability (and conversely, resilience) to the impact of sleep deprivation on memory formation. Moreover, this same measure of brain morphology was further associated with the quality of nonrapid eye movement slow wave oscillations during recovery sleep, and by way of such activity, determined the success of memory restoration. Such findings provide a novel human biomarker of cognitive susceptibility to, and recovery from, sleep deprivation. Moreover, this metric may be of special predictive utility for professions in which memory function is paramount yet insufficient sleep is pervasive (e.g., aviation, military, and medicine). SIGNIFICANCE STATEMENT Sleep deprivation does not impact all people equally. Some individuals show cognitive resilience to the effects of sleep loss, whereas others express striking vulnerability, the reasons for which remain largely unknown. Here, we demonstrate that structural features of the human brain, specifically those within the hippocampus, accurately predict which individuals are susceptible (or conversely, resilient) to memory impairments caused by sleep deprivation. Moreover, this same structural feature determines the success of memory restoration following subsequent recovery sleep. Therefore, structural properties of the human brain represent a novel biomarker predicting individual vulnerability to (and recovery from) the effects of sleep loss, one with occupational relevance in professions where insufficient sleep is pervasive yet memory function is paramount. PMID:26911684

  1. Forced splitting of human sleep in free-running rhythms

    OpenAIRE

    Zulley, Jürgen; Carr, D

    1992-01-01

    The assumption of polyphasic sleep/wake regulation is based on the occurrence of nap-sleep at specific phase positions in the circadian cycle. Further support would be the split of the normal long major sleep episode into shorter components. Evidence for this hypothesis comes from the discovery of bimodal distribution in sleep duration. An experimental approach to test this hypothesis has been carried out by restricting sleep duration in free-running rhythms. The outcome was a biphasic distri...

  2. How sleep and wakefulness influence circadian rhythmicity: effects of insufficient and mistimed sleep on the animal and human transcriptome.

    Science.gov (United States)

    Archer, Simon N; Oster, Henrik

    2015-10-01

    The mammalian circadian system is a multi-oscillator, hierarchically organised system where a central pacemaker synchronises behavioural, physiological and gene expression rhythms in peripheral tissues. Epidemiological studies show that disruption of this internal synchronisation by short sleep and shift work is associated with adverse health outcomes through mechanisms that remain to be elucidated. Here, we review recent animal and human studies demonstrating the profound effects of insufficient and mistimed sleep on the rhythms of gene expression in central and peripheral tissues. In mice, sleep restriction leads to an ~80% reduction in circadian transcripts in the brain and profound disruption of the liver transcriptome. In humans, sleep restriction leads to a 1.9% reduction in circadian transcripts in whole blood, and when sleep is displaced to the daytime, 97% of rhythmic genes become arrhythmic and one-third of all genes show changes in temporal expression profiles. These changes in mice and humans include a significant reduction in the circadian regulation of transcription and translation and core clock genes in the periphery, while at the same time rhythms within the suprachiasmatic nucleus are not disrupted. Although the physiological mediators of these sleep disruption effects on the transcriptome have not been established, altered food intake, changes in hormones such as cortisol, and changes in body and brain temperature may play important roles. Processes and molecular pathways associated with these disruptions include metabolism, immune function, inflammatory and stress responses, and point to the molecular mechanisms underlying the established adverse health outcomes associated with short sleep duration and shift work, such as metabolic syndrome and cancer. © 2015 European Sleep Research Society.

  3. Effects of humid heat exposure in later sleep segments on sleep stages and body temperature in humans

    Science.gov (United States)

    Okamoto-Mizuno, Kazue; Tsuzuki, Kazuyo; Mizuno, Koh

    2005-03-01

    This study sought to investigate the effects of humid heat exposure in later sleep segments on sleep stages and body temperature in humans. The subjects were eight healthy males, from whom informed consent had been obtained. The experiments were carried out under three different sets of conditions: a control climate [air temperature (Ta)=26°C, relative humidity (RH)=50%] (C); a humid heat climate (Ta=32°C, RH=80%) (H); and a humid heat exposure in later sleep segments (C for the first 3 h 45 min, followed by a 30-min transition to H, which was then maintained for the last 3 h 45 min) (C H). Electroencephalogram, EOG, and mental electromyogram, rectal temperature (Tre), and skin temperature (Tsk) were continuously measured. The total amount of wakefulness was significantly increased in H compared to C H or C. Compared to C, wakefulness in C H and H was significantly increased during later sleep segments. Tre and mean Tsk were significantly higher in H than in C H or C. In C H, Tsk and Tre increased to levels equal to those observed in H after Ta and RH increase. Whole body sweat loss was significantly lower in C H and C than in H. These results suggest that humid heat exposure in the later sleep segment reduces thermal load as compared to full-night humid heat exposure. In daily life, the use of air conditioning in the initial sleep hours can protect sleep and thermoregulation.

  4. Sleep deprivation increases cerebral serotonin 2A receptor binding in humans.

    Science.gov (United States)

    Elmenhorst, David; Kroll, Tina; Matusch, Andreas; Bauer, Andreas

    2012-12-01

    Serotonin and its cerebral receptors play an important role in sleep-wake regulation. The aim of the current study is to investigate the effect of 24-h total sleep deprivation on the apparent serotonin 2A receptor (5-HT(2A)R) binding capacity in the human brain to test the hypothesis that sleep deprivation induces global molecular alterations in the cortical serotonergic receptor system. Volunteers were tested twice with the subtype-selective radiotracer [(18)F]altanserin and positron emission tomography (PET) for imaging of 5-HT(2A)Rs at baseline and after 24 h of sleep deprivation. [(18)F]Altanserin binding potentials were analyzed in 13 neocortical regions of interest. The efficacy of sleep deprivation was assessed by questionnaires, waking electroencephalography, and cognitive performance measurements. Sleep laboratory and neuroimaging center. Eighteen healthy volunteers. Sleep deprivation. A total of 24 hours of sleep deprivation led to a 9.6% increase of [(18)F]altanserin binding on neocortical 5-HT(2A) receptors. Significant region-specific increases were found in the medial inferior frontal gyrus, insula, and anterior cingulate, parietal, sensomotoric, and ventrolateral prefrontal cortices. This study demonstrates that a single night of total sleep deprivation causes significant increases of 5-HT(2A)R binding potentials in a variety of cortical regions although the increase declines as sleep deprivation continued. It provides in vivo evidence that total sleep deprivation induces adaptive processes in the serotonergic system of the human brain.

  5. Electroencephalogram before and after body macromovements during the night sleep in humans

    NARCIS (Netherlands)

    Burikov, AA; Karmanova, IG; Litvinenko, SN

    1999-01-01

    A new material is presented about the universal role of movements on the background of human sleep. It has been shown that with deepening of the natural human night sleep the probability of occurrence of movements decreases, however, the probability that the movements will lead to changes of the

  6. Effects of interface pressure distribution on human sleep quality.

    Directory of Open Access Journals (Sweden)

    Zongyong Chen

    Full Text Available High sleep quality promotes efficient performance in the following day. Sleep quality is influenced by environmental factors, such as temperature, light, sound and smell. Here, we investigated whether differences in the interface pressure distribution on healthy individuals during sleep influenced sleep quality. We defined four types of pressure models by differences in the area distribution and the subjective feelings that occurred when participants slept on the mattresses. One type of model was showed "over-concentrated" distribution of pressure; one was displayed "over-evenly" distributed interface pressure while the other two models were displayed intermediate distribution of pressure. A polysomnography analysis demonstrated an increase in duration and proportion of non-rapid-eye-movement sleep stages 3 and 4, as well as decreased number of micro-arousals, in subjects sleeping on models with pressure intermediately distributed compared to models with over-concentrated or over-even distribution of pressure. Similarly, higher scores of self-reported sleep quality were obtained in subjects sleeping on the two models with intermediate pressure distribution. Thus, pressure distribution, at least to some degree, influences sleep quality and self-reported feelings of sleep-related events, though the underlying mechanisms remain unknown. The regulation of pressure models imposed by external sleep environment may be a new direction for improving sleep quality. Only an appropriate interface pressure distribution is beneficial for improving sleep quality, over-concentrated or -even distribution of pressure do not help for good sleep.

  7. Autonomic activity during sleep predicts memory consolidation in humans.

    Science.gov (United States)

    Whitehurst, Lauren N; Cellini, Nicola; McDevitt, Elizabeth A; Duggan, Katherine A; Mednick, Sara C

    2016-06-28

    Throughout history, psychologists and philosophers have proposed that good sleep benefits memory, yet current studies focusing on the relationship between traditionally reported sleep features (e.g., minutes in sleep stages) and changes in memory performance show contradictory findings. This discrepancy suggests that there are events occurring during sleep that have not yet been considered. The autonomic nervous system (ANS) shows strong variation across sleep stages. Also, increases in ANS activity during waking, as measured by heart rate variability (HRV), have been correlated with memory improvement. However, the role of ANS in sleep-dependent memory consolidation has never been examined. Here, we examined whether changes in cardiac ANS activity (HRV) during a daytime nap were related to performance on two memory conditions (Primed and Repeated) and a nonmemory control condition on the Remote Associates Test. In line with prior studies, we found sleep-dependent improvement in the Primed condition compared with the Quiet Wake control condition. Using regression analyses, we compared the proportion of variance in performance associated with traditionally reported sleep features (model 1) vs. sleep features and HRV during sleep (model 2). For both the Primed and Repeated conditions, model 2 (sleep + HRV) predicted performance significantly better (73% and 58% of variance explained, respectively) compared with model 1 (sleep only, 46% and 26% of variance explained, respectively). These findings present the first evidence, to our knowledge, that ANS activity may be one potential mechanism driving sleep-dependent plasticity.

  8. Forced splitting of human sleep in free-running rhythms.

    Science.gov (United States)

    Zulley; Carr

    1992-06-01

    The assumption of polyphasic sleep/wake regulation is based on the occurrence of nap-sleep at specific phase positions in the circadian cycle. Further support would be the split of the normal long major sleep episode into shorter components. Evidence for this hypothesis comes from the discovery of bimodal distribution in sleep duration. An experimental approach to test this hypothesis has been carried out by restricting sleep duration in free-running rhythms. The outcome was a biphasic distribution of sleep within a circadian cycle with sections of dissociation and synchronization of the two sleep blocks. The results show similarities with 'splitting', a phenomenon which has been found in animal studies. The relatively short duration of the different sections as well as the asymmetric distribution of the two sleep blocks in the circadian cycle leads to the assumption of a splitting of the major sleep episode and not of the circadian rhythm. Sleep split into two, relatively short sleep episodes of comparable duration contrasts with napping, which is characterized by an extra sleep episode in addition to the long major sleep.

  9. Impact of physical fitness and daily energy expenditure on sleep efficiency in young and older humans.

    Science.gov (United States)

    Oudegeest-Sander, Madelijn H; Eijsvogels, Thijs H M; Verheggen, Rebecca J H M; Poelkens, Fleur; Hopman, Maria T E; Jones, Helen; Thijssen, Dick H J

    2013-01-01

    Physical activity is known to influence sleep efficiency. Relatively little is known about the relationship between physical activity and sleep efficiency in young and older humans and the impact of exercise training on sleep efficiency in healthy older individuals. To determine the relationship between physical fitness and daily energy expenditure with sleep efficiency in young and older subjects, and assess the effect of 12-month exercise training on sleep efficiency in healthy older participants. The relationship between physical fitness (maximal cycling test) and daily energy expenditure (accelerometry) with sleep efficiency (accelerometry) was examined cross-sectionally in 12 healthy young adults (27 ± 5 years) and 21 healthy older participants (69 ± 3 years). Subsequently, the effect of 12-month exercise training (n = 11) or control period (n = 10) on sleep efficiency in older participants was examined using a randomized controlled trial. Daily energy expenditure and sleep efficiency did not differ between young and older subjects. A significant correlation was found between energy expenditure and sleep efficiency (r = 0.627, p = 0.029) in young adults, but not in older participants (r = -0.158, p = 0.49). Physical fitness did not correlate with sleep efficiency in either group. Exercise training significantly improved physical fitness (15.0%, p energy expenditure have greater sleep efficiency, whilst this relationship is diminished with advanced age. In contrast, we found no correlation between physical fitness and sleep characteristics in healthy young or older participants, which may explain the lack of improvement in sleep characteristics in older participants with 12-month exercise training. Exercise training may be more successful in subjects with existing sleep disturbances to improve sleep characteristics rather than in healthy older subjects. Copyright © 2012 S. Karger AG, Basel.

  10. Rhinal-hippocampal EEG coherence is reduced during human sleep.

    NARCIS (Netherlands)

    Fell, J.; Staedtgen, M.; Burr, W.; Kockelmann, E.; Helmstaedter, C.; Schaller, C.; Elger, C.E.; Fernandez, G.S.E.

    2003-01-01

    The deficiency of declarative memory compared with waking state is an often overlooked characteristic of sleep. Here, we investigated whether rhinal-hippocampal coherence, an electrophysiological correlate of declarative memory formation, is significantly altered during sleep as compared with waking

  11. Habitual sleep durations and subjective sleep quality predict white matter differences in the human brain

    Directory of Open Access Journals (Sweden)

    Sakh Khalsa

    2017-06-01

    Full Text Available Self-imposed short sleep durations are increasingly commonplace in society, and have considerable health and performance implications for individuals. Reduced sleep duration over multiple nights has similar behavioural effects to those observed following acute total sleep deprivation, suggesting that lack of sleep affects brain function cumulatively. A link between habitual sleep patterns and functional connectivity has previously been observed, and the effect of sleep duration on the brain's intrinsic functional architecture may provide a link between sleep status and cognition. However, it is currently not known whether differences in habitual sleep patterns across individuals are related to changes in the brain's white matter, which underlies structural connectivity. In the present study we use diffusion–weighted imaging and a group comparison application of tract based spatial statistics (TBSS to investigate changes to fractional anisotropy (FA and mean diffusivity (MD in relation to sleep duration and quality, hypothesising that white matter metrics would be positively associated with sleep duration and quality. Diffusion weighted imaging data was acquired from a final cohort of 33 (23–29 years, 10 female, mean 25.4 years participants. Sleep patterns were assessed for a 14 day period using wrist actigraphs and sleep diaries, and subjective sleep quality with the Pittsburgh Sleep Quality Index (PSQI. Median splits based on total sleep time and PSQI were used to create groups of shorter/longer and poorer/better sleepers, whose imaging data was compared using TBSS followed by post-hoc correlation analysis in regions identified as significantly different between the groups. There were significant positive correlations between sleep duration and FA in the left orbito-frontal region and the right superior corona radiata, and significant negative correlations between sleep duration and MD in right orbito-frontal white matter and the right

  12. Are Spatial Memories Strengthened in the Human Hippocampus during Slow Wave Sleep?

    OpenAIRE

    Peigneux, Philippe; Laureys, Steven; Fuchs, Sonia; Collette, Fabienne; Perrin, Fabien; Reggers, Jean; Phillips, Christophe; Degueldre, Christian; Del Fiore, Guy; Aerts, Joël; Luxen, André; Maquet, Pierre

    2004-01-01

    In rats, the firing sequences observed in hippocampal ensembles during spatial learning are replayed during subsequent sleep, suggesting a role for posttraining sleep periods in the offline processing of spatial memories. Here, using regional cerebral blood flow measurements, we show that, in humans, hippocampal areas that are activated during route learning in a virtual town are likewise activated during subsequent slow wave sleep. Most importantly, we found that the amount of hippocampal ac...

  13. Diurnal rhythms in the human urine metabolome during sleep and total sleep deprivation

    OpenAIRE

    Giskeødegård, Guro F; Davies, Sarah K.; Victoria L Revell; Hector Keun; Skene, Debra J.

    2015-01-01

    Understanding how metabolite levels change over the 24 hour day is of crucial importance for clinical and epidemiological studies. Additionally, the association between sleep deprivation and metabolic disorders such as diabetes and obesity requires investigation into the links between sleep and metabolism. Here, we characterise time-of-day variation and the effects of sleep deprivation on urinary metabolite profiles. Healthy male participants (n = 15) completed an in-laboratory study comprisi...

  14. Diurnal rhythms in the human urine metabolome during sleep and total sleep deprivation.

    Science.gov (United States)

    Giskeødegård, Guro F; Davies, Sarah K; Revell, Victoria L; Keun, Hector; Skene, Debra J

    2015-10-09

    Understanding how metabolite levels change over the 24 hour day is of crucial importance for clinical and epidemiological studies. Additionally, the association between sleep deprivation and metabolic disorders such as diabetes and obesity requires investigation into the links between sleep and metabolism. Here, we characterise time-of-day variation and the effects of sleep deprivation on urinary metabolite profiles. Healthy male participants (n = 15) completed an in-laboratory study comprising one 24 h sleep/wake cycle prior to 24 h of continual wakefulness under highly controlled environmental conditions. Urine samples were collected over set 2-8 h intervals and analysed by (1)H NMR spectroscopy. Significant changes were observed with respect to both time of day and sleep deprivation. Of 32 identified metabolites, 7 (22%) exhibited cosine rhythmicity over at least one 24 h period; 5 exhibiting a cosine rhythm on both days. Eight metabolites significantly increased during sleep deprivation compared with sleep (taurine, formate, citrate, 3-indoxyl sulfate, carnitine, 3-hydroxyisobutyrate, TMAO and acetate) and 8 significantly decreased (dimethylamine, 4-DTA, creatinine, ascorbate, 2-hydroxyisobutyrate, allantoin, 4-DEA, 4-hydroxyphenylacetate). These data indicate that sampling time, the presence or absence of sleep and the response to sleep deprivation are highly relevant when identifying biomarkers in urinary metabolic profiling studies.

  15. Regional Slow Waves and Spindles in Human Sleep

    Science.gov (United States)

    Nir, Yuval; Staba, Richard J.; Andrillon, Thomas; Vyazovskiy, Vladyslav V.; Cirelli, Chiara; Fried, Itzhak; Tononi, Giulio

    2011-01-01

    SUMMARY The most prominent EEG events in sleep are slow waves, reflecting a slow (waves and the underlying active and inactive neuronal states occur locally. Thus, especially in late sleep, some regions can be active while others are silent. We also find that slow waves can propagate, usually from medial prefrontal cortex to the medial temporal lobe and hippocampus. Sleep spindles, the other hallmark of NREM sleep EEG, are likewise predominantly local. Thus, intracerebral communication during sleep is constrained because slow and spindle oscillations often occur out-of-phase in different brain regions. PMID:21482364

  16. Evidence That Sleep Deprivation Downregulates Dopamine D2R in Ventral Striatum in the Human Brain

    Energy Technology Data Exchange (ETDEWEB)

    Volkow N. D.; Fowler J.; Volkow, N.D.; Tomasi, D.; Wang, G.-J.; Fowler, J.S.; Logan, J.; Benveniste, H.; Kin, R.; Thanos, P.K.; Sergi F.

    2012-03-23

    Dopamine D2 receptors are involved with wakefulness, but their role in the decreased alertness associated with sleep deprivation is unclear. We had shown that sleep deprivation reduced dopamine D2/D3 receptor availability (measured with PET and [{sup 11}C]raclopride in controls) in striatum, but could not determine whether this reflected dopamine increases ([{sup 11}C]raclopride competes with dopamine for D2/D3 receptor binding) or receptor downregulation. To clarify this, we compared the dopamine increases induced by methylphenidate (a drug that increases dopamine by blocking dopamine transporters) during sleep deprivation versus rested sleep, with the assumption that methylphenidate's effects would be greater if, indeed, dopamine release was increased during sleep deprivation. We scanned 20 controls with [{sup 11}C]raclopride after rested sleep and after 1 night of sleep deprivation; both after placebo and after methylphenidate. We corroborated a decrease in D2/D3 receptor availability in the ventral striatum with sleep deprivation (compared with rested sleep) that was associated with reduced alertness and increased sleepiness. However, the dopamine increases induced by methylphenidate (measured as decreases in D2/D3 receptor availability compared with placebo) did not differ between rested sleep and sleep deprivation, and were associated with the increased alertness and reduced sleepiness when methylphenidate was administered after sleep deprivation. Similar findings were obtained by microdialysis in rodents subjected to 1 night of paradoxical sleep deprivation. These findings are consistent with a downregulation of D2/D3 receptors in ventral striatum with sleep deprivation that may contribute to the associated decreased wakefulness and also corroborate an enhancement of D2 receptor signaling in the arousing effects of methylphenidate in humans.

  17. Neural Markers of Responsiveness to the Environment in Human Sleep

    DEFF Research Database (Denmark)

    Andrillon, Thomas; Poulsen, Andreas Trier; Hansen, Lars Kai

    2016-01-01

    Sleep is characterized by a loss of behavioral responsiveness. However, recent research has shown that the sleeping brain is not completely disconnected from its environment. How neural activity constrains the ability to process sensory information while asleep is yet unclear. Here, we instructed...... by Lempel-Ziv complexity (LZc), a measure shown to track arousal in sleep and anesthesia. Neural activity related to the semantic content of stimuli was conserved in light non-rapid eye movement (NREM) sleep. However, these processes were suppressed in deep NREM sleep and, importantly, also in REM sleep......, despite the recovery of wake-like neural activity in the latter. In NREM sleep, sensory activations were counterbalanced by evoked down states, which, when present, blocked further processing of external information. In addition, responsiveness markers correlated positively with baseline complexity, which...

  18. Sleep Disruption, Safety Learning, and Fear Extinction in Humans: Implications for Posttraumatic Stress Disorder.

    Science.gov (United States)

    Straus, Laura D; Drummond, Sean P A; Risbrough, Victoria B; Norman, Sonya B

    2017-09-24

    Fear learning is critical in the development and maintenance of posttraumatic stress disorder (PTSD) symptoms, and safety learning and extinction are necessary for recovery. Studies in animal models suggest that sleep disruption, and REM sleep fragmentation in particular, interfere with safety learning and extinction processes, and recently, studies are extending these findings to humans. A discussion of the human literature is presented here, which largely consists of experimental studies in healthy human control subjects. A theoretical model for the relationship between fear learning, sleep disruption, and impaired safety learning and extinction is proposed, which provides an explanatory framework for sleep disruption and its relationship to PTSD. Overall, findings suggest that sleep disruption plays a role in the development and maintenance of PTSD symptoms, and thus presents an important modifiable target in PTSD treatment.

  19. Effect of sleep deprivation on rhythms of clock gene expression and melatonin in humans.

    OpenAIRE

    Ackermann, K; Plomp, R; Lao, O; Middleton, B; Revell, VL; Skene, DJ; Kayser, M

    2013-01-01

    This study investigated the impact of sleep deprivation on the human circadian system. Plasma melatonin and cortisol levels and leukocyte expression levels of 12 genes were examined over 48 h (sleep vs. no-sleep nights) in 12 young males (mean ± SD: 23 ± 5 yrs). During one night of total sleep deprivation, BMAL1 expression was suppressed, the heat shock gene HSPA1B expression was induced, and the amplitude of the melatonin rhythm increased, whereas other high-amplitude clock gene rhythms (e.g...

  20. Millisecond flashes of light phase delay the human circadian clock during sleep.

    Science.gov (United States)

    Zeitzer, Jamie M; Fisicaro, Ryan A; Ruby, Norman F; Heller, H Craig

    2014-10-01

    The human circadian timing system is most sensitive to the phase-shifting effects of light during the biological nighttime, a time at which humans are most typically asleep. The overlap of sleep with peak sensitivity to the phase-shifting effects of light minimizes the effectiveness of using light as a countermeasure to circadian misalignment in humans. Most current light exposure treatments for such misalignment are mostly ineffective due to poor compliance and secondary changes that cause sleep deprivation. Using a 16-day, parallel group design, we examined whether a novel sequence of light flashes delivered during sleep could evoke phase changes in the circadian system without disrupting sleep. Healthy volunteers participated in a 2-week circadian stabilization protocol followed by a 2-night laboratory stay. During the laboratory session, they were exposed during sleep to either darkness (n = 7) or a sequence of 2-msec light flashes given every 30 sec (n = 6) from hours 2 to 3 after habitual bedtime. Changes in circadian timing (phase) and micro- and macroarchitecture of sleep were assessed. Subjects exposed to the flash sequence during sleep exhibited a delay in the timing of their circadian salivary melatonin rhythm compared with the control dark condition (p circadian timing, there were no large changes in either the amount or spectral content of sleep (p values > 0.30) during the flash stimulus. Exposing sleeping individuals to 0.24 sec of light spread over an hour shifted the timing of the circadian clock and did so without major alterations to sleep itself. While a greater number of matched subjects and more research will be necessary to ascertain whether these light flashes affect sleep, our data suggest that this type of passive phototherapy might be developed as a useful treatment for circadian misalignment in humans. © 2014 The Author(s).

  1. Short Sleep Makes Declarative Memories Vulnerable to Stress in Humans.

    Science.gov (United States)

    Cedernaes, Jonathan; Rångtell, Frida H; Axelsson, Emil K; Yeganeh, Adine; Vogel, Heike; Broman, Jan-Erik; Dickson, Suzanne L; Schiöth, Helgi B; Benedict, Christian

    2015-12-01

    This study sought to investigate the role of nocturnal sleep duration for the retrieval of oversleep consolidated memories, both prior to and after being cognitively stressed for ∼30 minutes the next morning. Participants learned object locations (declarative memory task comprising 15 card pairs) and a finger tapping sequence (procedural memory task comprising 5 digits) in the evening. After learning, participants either had a sleep opportunity of 8 hours (between ∼23:00 and ∼07:00, full sleep condition) or they could sleep between ∼03:00 and ∼07:00 (short sleep condition). Retrieval of both memory tasks was tested in the morning after each sleep condition, both before (∼08:30) and after being stressed (∼09:50). Sleep laboratory. 15 healthy young men. The analyses demonstrated that oversleep memory changes did not differ between sleep conditions. However, in their short sleep condition, following stress hallmarked by increased subjective stress feelings, the men were unable to maintain their pre-stress performance on the declarative memory task, whereas their performance on the procedural memory task remained unchanged. While men felt comparably subjectively stressed by the stress intervention, overall no differences between pre- and post-stress recalls were observed following a full night of sleep. The findings suggest that 8-h sleep duration, within the range recommended by the US National Sleep Foundation, may not only help consolidate newly learned procedural and declarative memories, but also ensure full access to both during periods of subjective stress. © 2015 Associated Professional Sleep Societies, LLC.

  2. Increased sleep fragmentation leads to impaired off-line consolidation of motor memories in humans.

    Directory of Open Access Journals (Sweden)

    Ina Djonlagic

    Full Text Available A growing literature supports a role for sleep after training in long-term memory consolidation and enhancement. Consequently, interrupted sleep should result in cognitive deficits. Recent evidence from an animal study indeed showed that optimal memory consolidation during sleep requires a certain amount of uninterrupted sleep. Sleep continuity is disrupted in various medical disorders. We compared performance on a motor sequence learning task (MST in relatively young subjects with obstructive sleep apnea (n = 16; apnea-hypopnea index 17.1±2.6/h [SEM] to a carefully matched control group (n = 15, apnea-hypopnea index 3.7±0.4/h, p<0.001. Apart from AHI, oxygen nadir and arousal index, there were no significant differences between groups in total sleep time, sleep efficiency and sleep architecture as well as subjective measures of sleepiness based on standard questionnaires. In addition performance on the psychomotor vigilance task (reaction time and lapses, which is highly sensitive to sleep deprivation showed no differences as well as initial learning performance during the training phase. However there was a significant difference in the primary outcome of immediate overnight improvement on the MST between the two groups (controls = 14.7±4%, patients = 1.1±3.6%; P = 0.023 as well as plateau performance (controls = 24.0±5.3%, patients = 10.1±2.0%; P = 0.017 and this difference was predicted by the arousal index (p = 0.02 rather than oxygen saturation (nadir and time below 90% saturation. Taken together, this outcome provides evidence that there is a clear minimum requirement of sleep continuity in humans to ensure optimal sleep dependent memory processes. It also provides important new information about the cognitive impact of obstructive sleep apnea and challenges its current definitions.

  3. The large-scale functional connectivity correlates of consciousness and arousal during the healthy and pathological human sleep cycle

    NARCIS (Netherlands)

    Tagliazucchi, E.; van Someren, Eus J W

    2017-01-01

    Advances in neuroimaging have greatly improved our understanding of human sleep from a systems neuroscience perspective. However, cognition and awareness are reduced during sleep, hindering the applicability of standard task-based paradigms. Methods recently developed to study spontaneous brain

  4. Dynamics of sleep-wake cyclicity at night across the human lifespan

    Directory of Open Access Journals (Sweden)

    Hrönn Arnardóttir

    2010-12-01

    Full Text Available Studies in adult mammals (rats, cats, mice, and humans have revealed a surprising regularity in the duration of sleep and wake bouts. In particular, wake bout durations exhibit a power-law distribution whereas sleep bout durations exhibit an exponential distribution. Moreover, in rodents, sleep bouts exhibit an exponential distribution at all ages examined, whereas wake bout durations exhibit exponential distributions early in ontogeny with a clear power-law emerging only at the older ages. Thus, the data examined thus far suggests a similar developmental trajectory for a wide range of mammals which in turn may offer a novel metric to directly compare human and animal sleep-wake data. Therefore, we tested the generalizability of these findings by examining the distributions of sleep and wake bouts during the night in a healthy human sample – from premature infants to 70-year-olds. We find that sleep bouts elongate over the first years. At the same time wake bouts shorten but elongate again with increasing age. Moreover, sleep bout durations exhibit exponential distributions at all ages tested, except for the youngest (premature infants. Wake bouts exhibit a power-law distribution - but only during a restricted time window during adulthood. We conclude that the developmental trajectory of human sleep-wake cycles does not map well onto those of rodents; however, the method of characterizing sleep-wake cycles, using bout distribution, holds great promise for classifying sleep, its disorders, and tracking its developmental milestones across the life-span in humans.

  5. White blood cells and cortisol after sleep deprivation and recovery sleep in humans.

    Science.gov (United States)

    Heiser, P; Dickhaus, B; Schreiber, W; Clement, H W; Hasse, C; Hennig, J; Remschmidt, H; Krieg, J C; Wesemann, W; Opper, C

    2000-01-01

    Sleep deprivation (SD) has enriched our treatment programme for major depression. SD has been demonstrated to modify different host defence activities. There is some evidence that there are reciprocal relationships between immune function and increased hypothalamic-pituitary-adrenocortical (HPA) axis activity in depression. We therefore investigated the number of leukocytes, granulocytes, monocytes, lymphocytes, B cells, T cells, helper T cells, cytotoxic T cells, NK cells and salivary cortisol in 10 healthy men before and after total SD (TSD) as well as after recovery sleep. Blood samples were drawn on 3 consecutive days at 7 am, 1 pm and 7 pm, respectively. Comparison of the 7 am values by contrast analysis yielded significant differences for granulocytes (p = 0.044) and NK cells (p = 0.001) after SD and recovery sleep. NK cells decreased and granulocytes increased after SD and after recovery sleep. Significant differences between single points in time across the day were found for granulocytes (p = 0.022), monocytes (p = 0.031), T cells (p = 0.005), helper T cells (p = 0.004), cytotoxic T cells (p = 0.005) and NK cells (p = 0.017). No significant difference could be detected for leukocytes, lymphocytes and B cells counts. These results favour the thesis that SD and recovery sleep lead to changes in the distribution of peripheral leukocytes, especially in a reduction of NK cells after SD and recovery sleep. The cortisol rhythm was affected neither by SD nor recovery sleep.

  6. Are spatial memories strengthened in the human hippocampus during slow wave sleep?

    Science.gov (United States)

    Peigneux, Philippe; Laureys, Steven; Fuchs, Sonia; Collette, Fabienne; Perrin, Fabien; Reggers, Jean; Phillips, Christophe; Degueldre, Christian; Del Fiore, Guy; Aerts, Joël; Luxen, André; Maquet, Pierre

    2004-10-28

    In rats, the firing sequences observed in hippocampal ensembles during spatial learning are replayed during subsequent sleep, suggesting a role for posttraining sleep periods in the offline processing of spatial memories. Here, using regional cerebral blood flow measurements, we show that, in humans, hippocampal areas that are activated during route learning in a virtual town are likewise activated during subsequent slow wave sleep. Most importantly, we found that the amount of hippocampal activity expressed during slow wave sleep positively correlates with the improvement of performance in route retrieval on the next day. These findings suggest that learning-dependent modulation in hippocampal activity during human sleep reflects the offline processing of recent episodic and spatial memory traces, which eventually leads to the plastic changes underlying the subsequent improvement in performance.

  7. Adenosine A{sub 1} receptors in human sleep regulation studied by electroencephalography (EEG) and positron emission tomography (PET)[Dissertation 17227

    Energy Technology Data Exchange (ETDEWEB)

    Geissler, E

    2007-07-01

    Sleep is an essential physiological process. However, the functions of sleep and the endogenous mechanisms involved in sleep regulation are only partially understood. Convergent lines of evidence support the hypothesis that the build-up of sleep propensity during wakefulness and its decline during sleep are associated with alterations in brain adenosine levels and adenosine receptor concentrations. The non-selective A{sub 1} and A{sub 2A} adenosine receptor antagonist caffeine stimulates alertness and is known to attenuate changes in the waking and sleep electroencephalogram (EEG) typically observed after prolonged waking. Several findings point to an important function of the adenosine A{sub 1} receptor (A{sub 1}AR) in the modulation of vigilance states. The A{sub 1}AR is densely expressed in brain regions involved in sleep regulation, and pharmacological manipulations affecting the A{sub 1}AR were shown to influence sleep propensity and sleep depth. However, an involvement of the A{sub 2A} adenosine receptor (A{sub 2A}AR) is also assumed. The distinct functions of the A{sub 1} and A{sub 2A} receptor subtypes in sleep-wake regulation and in mediating the effects of caffeine have not been identified so far. The selective adenosine A{sub 1} receptor antagonist, 8-cyclopentyl-3-(3-{sup 18}Ffluoropropyl)- 1-propylxanthine ({sup 18}F-CPFPX), offers the opportunity to get further insights into adenosinergic mechanisms by in vivo imaging of the A{sub 1}AR subtype with positron emission tomography (PET). The aim of this thesis was to elucidate the role of adenosine A{sub 1} receptors in human sleep regulation, combining {sup 18}F-CPFPX PET brain imaging and EEG recordings, the gold standard in sleep research. It was hypothesized that sleep deprivation would induce adenosine accumulation and/or changes in A{sub 1}AR density. Thus, the question was addressed whether these effects of prolonged wakefulness can be visualized by altered {sup 18}F-CPFPX binding. Moreover, it was

  8. Adverse metabolic consequences in humans of prolonged sleep restriction combined with circadian disruption.

    Science.gov (United States)

    Buxton, Orfeu M; Cain, Sean W; O'Connor, Shawn P; Porter, James H; Duffy, Jeanne F; Wang, Wei; Czeisler, Charles A; Shea, Steven A

    2012-04-11

    Epidemiological studies link short sleep duration and circadian disruption with higher risk of metabolic syndrome and diabetes. We tested the hypotheses that prolonged sleep restriction with concurrent circadian disruption, as can occur in people performing shift work, impairs glucose regulation and metabolism. Healthy adults spent >5 weeks under controlled laboratory conditions in which they experienced an initial baseline segment of optimal sleep, 3 weeks of sleep restriction (5.6 hours of sleep per 24 hours) combined with circadian disruption (recurring 28-hour "days"), followed by 9 days of recovery sleep with circadian re-entrainment. Exposure to prolonged sleep restriction with concurrent circadian disruption, with measurements taken at the same circadian phase, decreased the participants' resting metabolic rate and increased plasma glucose concentrations after a meal, an effect resulting from inadequate pancreatic insulin secretion. These parameters normalized during the 9 days of recovery sleep and stable circadian re-entrainment. Thus, in humans, prolonged sleep restriction with concurrent circadian disruption alters metabolism and could increase the risk of obesity and diabetes.

  9. Discharge Patterns of Human Tensor Palatini Motor Units During Sleep Onset

    Science.gov (United States)

    Nicholas, Christian L.; Jordan, Amy S.; Heckel, Leila; Worsnop, Christopher; Bei, Bei; Saboisky, Julian P.; Eckert, Danny J.; White, David P.; Malhotra, Atul; Trinder, John

    2012-01-01

    Study Objectives: Upper airway muscles such as genioglossus (GG) and tensor palatini (TP) reduce activity at sleep onset. In GG reduced muscle activity is primarily due to inspiratory modulated motor units becoming silent, suggesting reduced respiratory pattern generator (RPG) output. However, unlike GG, TP shows minimal respiratory modulation and presumably has few inspiratory modulated motor units and minimal input from the RPG. Thus, we investigated the mechanism by which TP reduces activity at sleep onset. Design: The activity of TP motor units were studied during relaxed wakefulness and over the transition from wakefulness to sleep. Setting: Sleep laboratory. Participants: Nine young (21.4 ± 3.4 years) males were studied on a total of 11 nights. Intervention: Sleep onset. Measurements and Results: Two TP EMGs (thin, hooked wire electrodes), and sleep and respiratory measures were recorded. One hundred twenty-one sleep onsets were identified (13.4 ± 7.2/subject), resulting in 128 motor units (14.3 ± 13.0/subject); 29% of units were tonic, 43% inspiratory modulated (inspiratory phasic 18%, inspiratory tonic 25%), and 28% expiratory modulated (expiratory phasic 21%, expiratory tonic 7%). There was a reduction in both expiratory and inspiratory modulated units, but not tonic units, at sleep onset. Reduced TP activity was almost entirely due to de-recruitment. Conclusions: TP showed a similar distribution of motor units as other airway muscles. However, a greater proportion of expiratory modulated motor units were active in TP and these expiratory units, along with inspiratory units, tended to become silent over sleep onset. The data suggest that both expiratory and inspiratory drive components from the RPG are reduced at sleep onset in TP. Citation: Nicholas CL; Jordan AS; Heckel L; Worsnop C; Bei B: Saboisky JP; Eckert DJ; White DP; Malhotra A; Trinder J. Discharge patterns of human tensor palatini motor units during sleep onset. SLEEP 2012;35(5):699-707. PMID

  10. Acute exposure to evening blue-enriched light impacts on human sleep.

    Science.gov (United States)

    Chellappa, Sarah L; Steiner, Roland; Oelhafen, Peter; Lang, Dieter; Götz, Thomas; Krebs, Julia; Cajochen, Christian

    2013-10-01

    Light in the short wavelength range (blue light: 446-483 nm) elicits direct effects on human melatonin secretion, alertness and cognitive performance via non-image-forming photoreceptors. However, the impact of blue-enriched polychromatic light on human sleep architecture and sleep electroencephalographic activity remains fairly unknown. In this study we investigated sleep structure and sleep electroencephalographic characteristics of 30 healthy young participants (16 men, 14 women; age range 20-31 years) following 2 h of evening light exposure to polychromatic light at 6500 K, 2500 K and 3000 K. Sleep structure across the first three non-rapid eye movement non-rapid eye movement - rapid eye movement sleep cycles did not differ significantly with respect to the light conditions. All-night non-rapid eye movement sleep electroencephalographic power density indicated that exposure to light at 6500 K resulted in a tendency for less frontal non-rapid eye movement electroencephalographic power density, compared to light at 2500 K and 3000 K. The dynamics of non-rapid eye movement electroencephalographic slow wave activity (2.0-4.0 Hz), a functional index of homeostatic sleep pressure, were such that slow wave activity was reduced significantly during the first sleep cycle after light at 6500 K compared to light at 2500 K and 3000 K, particularly in the frontal derivation. Our data suggest that exposure to blue-enriched polychromatic light at relatively low room light levels impacts upon homeostatic sleep regulation, as indexed by reduction in frontal slow wave activity during the first non-rapid eye movement episode. © 2013 European Sleep Research Society.

  11. Effects of sleep restriction on the human plasma metabolome.

    Science.gov (United States)

    Bell, Lauren N; Kilkus, Jennifer M; Booth, John N; Bromley, Lindsay E; Imperial, Jacqueline G; Penev, Plamen D

    2013-10-02

    This study examined the effects of recurrent sleep restriction on the plasma metabolome of adults with familial risk of type 2 diabetes. Eleven healthy adults (6M/5F; mean [SD] age: 26 [3]years; BMI 23.5 [2.3]kg/m(2)) with parental history of type 2 diabetes participated in a two-condition, two-period randomized crossover study at the Clinical Resource Center at an academic hospital. Each participant completed two 8-night inpatient sessions with restricted (5.5-h time-in-bed) vs. adequate (8.5-h time-in-bed) sleep opportunity while daily food intake and physical activity were carefully controlled. A combination of two UHPLC/MS/MS platforms and one GC/MS platform was used to measure 362 biochemicals in fasting plasma samples collected from study participants the morning after each 8-night sleep treatment. Relative concentrations of 12 amino acids and related metabolites were increased when sleep was curtailed. Sleep restriction also induced elevations in several fatty acid, bile acid, steroid hormone, and tricarboxylic acid cycle intermediates. In contrast, circulating levels of glucose, some monosaccharides, gluconate, and five-carbon sugar alcohols tended to decline when sleep was reduced. Recurrent sleep curtailment affected multiple pathways of intermediary metabolism in adults at risk for type 2 diabetes. An elevation in plasma amino acids and related biochemicals was the most pronounced metabolic signature seen in response to 8 nights of sleep restriction. © 2013.

  12. Population Propensity Measurement Model

    Science.gov (United States)

    1993-12-01

    positive propensity rapidly declines. This suggests that the 16 to 18 year-old group is possibly the best group at which recruiting efforts should be...Prior Service Market Analysis. AFMPXOA, Pentagon, Washington, DC. Saving, T.R., Stone, B.M., Looper, L.T., and TayloT , J.N., (1985). Retention of Air

  13. Human Hippocampal Structure: A Novel Biomarker Predicting Mnemonic Vulnerability to, and Recovery from, Sleep Deprivation.

    Science.gov (United States)

    Saletin, Jared M; Goldstein-Piekarski, Andrea N; Greer, Stephanie M; Stark, Shauna; Stark, Craig E; Walker, Matthew P

    2016-02-24

    Sleep deprivation impairs the formation of new memories. However, marked interindividual variability exists in the degree to which sleep loss compromises learning, the mechanistic reasons for which are unclear. Furthermore, which physiological sleep processes restore learning ability following sleep deprivation are similarly unknown. Here, we demonstrate that the structural morphology of human hippocampal subfields represents one factor determining vulnerability (and conversely, resilience) to the impact of sleep deprivation on memory formation. Moreover, this same measure of brain morphology was further associated with the quality of nonrapid eye movement slow wave oscillations during recovery sleep, and by way of such activity, determined the success of memory restoration. Such findings provide a novel human biomarker of cognitive susceptibility to, and recovery from, sleep deprivation. Moreover, this metric may be of special predictive utility for professions in which memory function is paramount yet insufficient sleep is pervasive (e.g., aviation, military, and medicine). Copyright © 2016 the authors 0270-6474/16/362355-09$15.00/0.

  14. Human and rat gut microbiome composition is maintained following sleep restriction.

    Science.gov (United States)

    Zhang, Shirley L; Bai, Lei; Goel, Namni; Bailey, Aubrey; Jang, Christopher J; Bushman, Frederic D; Meerlo, Peter; Dinges, David F; Sehgal, Amita

    2017-02-21

    Insufficient sleep increasingly characterizes modern society, contributing to a host of serious medical problems. Loss of sleep is associated with metabolic diseases such as obesity and diabetes, cardiovascular disorders, and neurological and cognitive impairments. Shifts in gut microbiome composition have also been associated with the same pathologies; therefore, we hypothesized that sleep restriction may perturb the gut microbiome to contribute to a disease state. In this study, we examined the fecal microbiome by using a cross-species approach in both rat and human studies of sleep restriction. We used DNA from hypervariable regions (V1-V2) of 16S bacteria rRNA to define operational taxonomic units (OTUs) of the microbiome. Although the OTU richness of the microbiome is decreased by sleep restriction in rats, major microbial populations are not altered. Only a single OTU, TM7-3a, was found to increase with sleep restriction of rats. In the human microbiome, we find no overt changes in the richness or composition induced by sleep restriction. Together, these results suggest that the microbiome is largely resistant to changes during sleep restriction.

  15. Human and rat gut microbiome composition is maintained following sleep restriction

    Science.gov (United States)

    Zhang, Shirley L.; Bai, Lei; Goel, Namni; Bailey, Aubrey; Jang, Christopher J.; Bushman, Frederic D.; Meerlo, Peter; Dinges, David F.; Sehgal, Amita

    2017-01-01

    Insufficient sleep increasingly characterizes modern society, contributing to a host of serious medical problems. Loss of sleep is associated with metabolic diseases such as obesity and diabetes, cardiovascular disorders, and neurological and cognitive impairments. Shifts in gut microbiome composition have also been associated with the same pathologies; therefore, we hypothesized that sleep restriction may perturb the gut microbiome to contribute to a disease state. In this study, we examined the fecal microbiome by using a cross-species approach in both rat and human studies of sleep restriction. We used DNA from hypervariable regions (V1-V2) of 16S bacteria rRNA to define operational taxonomic units (OTUs) of the microbiome. Although the OTU richness of the microbiome is decreased by sleep restriction in rats, major microbial populations are not altered. Only a single OTU, TM7-3a, was found to increase with sleep restriction of rats. In the human microbiome, we find no overt changes in the richness or composition induced by sleep restriction. Together, these results suggest that the microbiome is largely resistant to changes during sleep restriction. PMID:28179566

  16. Circadian regulation of slow waves in human sleep: Topographical aspects

    Science.gov (United States)

    Lazar, Alpar S.; Lazar, Zsolt I.; Dijk, Derk-Jan

    2015-01-01

    Slow waves (SWs, 0.5–4 Hz) in field potentials during sleep reflect synchronized alternations between bursts of action potentials and periods of membrane hyperpolarization of cortical neurons. SWs decline during sleep and this is thought to be related to a reduction of synaptic strength in cortical networks and to be central to sleep's role in maintaining brain function. A central assumption in current concepts of sleep function is that SWs during sleep, and associated recovery processes, are independent of circadian rhythmicity. We tested this hypothesis by quantifying all SWs from 12 EEG derivations in 34 participants in whom 231 sleep periods were scheduled across the circadian cycle in a 10-day forced-desynchrony protocol which allowed estimation of the separate circadian and sleep-dependent modulation of SWs. Circadian rhythmicity significantly modulated the incidence, amplitude, frequency and the slope of the SWs such that the peaks of the circadian rhythms in these slow-wave parameters were located during the biological day. Topographical analyses demonstrated that the sleep-dependent modulation of SW characteristics was most prominent in frontal brain areas whereas the circadian effect was similar to or greater than the sleep-dependent modulation over the central and posterior brain regions. The data demonstrate that circadian rhythmicity directly modulates characteristics of SWs thought to be related to synaptic plasticity and that this modulation depends on topography. These findings have implications for the understanding of local sleep regulation and conditions such as ageing, depression, and neurodegeneration which are associated with changes in SWs, neural plasticity and circadian rhythmicity. PMID:25979664

  17. Light modulation of human sleep depends on a polymorphism in the clock gene Period3.

    Science.gov (United States)

    Chellappa, Sarah L; Viola, Antoine U; Schmidt, Christina; Bachmann, Valérie; Gabel, Virginie; Maire, Micheline; Reichert, Carolin F; Valomon, Amandine; Landolt, Hans-Peter; Cajochen, Christian

    2014-09-01

    Non-image-forming (NIF) responses to light powerfully modulate human physiology. However, it remains scarcely understood how NIF responses to light modulate human sleep and its EEG hallmarks, and if there are differences across individuals. Here we investigated NIF responses to light on sleep in individuals genotyped for the PERIOD3 (PER3) variable-number tandem-repeat (VNTR) polymorphism. Eighteen healthy young men (20-28 years; mean ± SEM: 25.9 ± 1.2) homozygous for the PER3 polymorphism were matched by age, body-mass index, and ethnicity. The study protocol comprised a balanced cross-over design during the winter, during which participants were exposed to either light of 40 lx at 6,500 K (blue-enriched) or light at 2,500 K (non-blue enriched), during 2h in the evening. Compared to light at 2,500 K, light at 6,500 K induced a significant increase in all-night NREM sleep slow-wave activity (SWA: 1.0-4.5 Hz) in the occipital cortex for PER3(5/5) individuals, but not for PER3(4/4) volunteers. Dynamics of SWA across sleep cycles revealed increased occipital NREM sleep SWA for virtually all sleep episode only for PER3(5/5) individuals. Furthermore, they experienced light at 6,500 K as significantly brighter. Intriguingly, this subjective perception of brightness significantly predicted their increased occipital SWA throughout the sleep episode. Our data indicate that humans homozygous for the PER3(5/5) allele are more sensitive to NIF light effects, as indexed by specific changes in sleep EEG activity. Ultimately, individual differences in NIF light responses on sleep may depend on a clock gene polymorphism involved in sleep-wake regulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Sleep and Obesity: A focus on animal models

    Science.gov (United States)

    Mavanji, Vijayakumar; Billington, Charles J.; Kotz, Catherine M.; Teske, Jennifer A.

    2012-01-01

    The rapid rise in obesity prevalence in the modern world parallels a significant reduction in restorative sleep (Agras et al., 2004; Dixon et al., 2007; Dixon et al., 2001; Gangwisch and Heymsfield, 2004; Gupta et al., 2002; Sekine et al., 2002; Vioque et al., 2000; Wolk et al., 2003). Reduced sleep time and quality increases the risk for obesity, but the underlying mechanisms remain unclear (Gangwisch et al., 2005; Hicks et al., 1986; Imaki et al., 2002; Jennings et al., 2007; Moreno et al., 2006). A majority of the theories linking human sleep disturbances and obesity rely on self-reported sleep. However, studies with objective measurements of sleep/wake parameters suggest a U-shaped relationship between sleep and obesity. Studies in animal models are needed to improve our understanding of the association between sleep disturbances and obesity. Genetic and experimenter-induced models mimicking characteristics of human obesity are now available and these animal models will be useful in understanding whether sleep disturbances determine propensity for obesity, or result from obesity. These models exhibit weight gain profiles consistently different from control animals. Thus a careful evaluation of animal models will provide insight into the relationship between sleep disturbances and obesity in humans. In this review we first briefly consider the fundamentals of sleep and key sleep disturbances, such as sleep fragmentation and excessive daytime sleepiness (EDS), observed in obese individuals. Then we consider sleep deprivation studies and the role of circadian alterations in obesity. We describe sleep/wake changes in various rodent models of obesity and obesity resistance. Finally, we discuss possible mechanisms linking sleep disturbances with obesity. PMID:22266350

  19. Sleep and obesity: a focus on animal models.

    Science.gov (United States)

    Mavanji, Vijayakumar; Billington, Charles J; Kotz, Catherine M; Teske, Jennifer A

    2012-03-01

    The rapid rise in obesity prevalence in the modern world parallels a significant reduction in restorative sleep (Agras et al., 2004; Dixon et al., 2007, 2001; Gangwisch and Heymsfield, 2004; Gupta et al., 2002; Sekine et al., 2002; Vioque et al., 2000; Wolk et al., 2003). Reduced sleep time and quality increases the risk for obesity, but the underlying mechanisms remain unclear (Gangwisch et al., 2005; Hicks et al., 1986; Imaki et al., 2002; Jennings et al., 2007; Moreno et al., 2006). A majority of the theories linking human sleep disturbances and obesity rely on self-reported sleep. However, studies with objective measurements of sleep/wake parameters suggest a U-shaped relationship between sleep and obesity. Studies in animal models are needed to improve our understanding of the association between sleep disturbances and obesity. Genetic and experimenter-induced models mimicking characteristics of human obesity are now available and these animal models will be useful in understanding whether sleep disturbances determine propensity for obesity, or result from obesity. These models exhibit weight gain profiles consistently different from control animals. Thus a careful evaluation of animal models will provide insight into the relationship between sleep disturbances and obesity in humans. In this review we first briefly consider the fundamentals of sleep and key sleep disturbances, such as sleep fragmentation and excessive daytime sleepiness (EDS), observed in obese individuals. Then we consider sleep deprivation studies and the role of circadian alterations in obesity. We describe sleep/wake changes in various rodent models of obesity and obesity resistance. Finally, we discuss possible mechanisms linking sleep disturbances with obesity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. How Much Sleep Is Enough

    Science.gov (United States)

    ... June 7, 2017 Sleep Infographic Sleep Disorders & Insufficient Sleep: Improving Health through Research National Institutes of Health- (NIH) supported research is shedding light on how sleep and lack of sleep affect the human body. ...

  1. The mathematical structure of the human sleep-wake cycle

    CERN Document Server

    Strogatz, Steven H

    1986-01-01

    Over the past three years I have grown accustomed to the puzzled look which appears on people's faces when they hear that I am a mathematician who studies sleep. They wonder, but are usually too polite to ask, what does mathematics have to do with sleep? Instead they ask the questions that fascinate us all: Why do we have to sleep? How much sleep do we really need? Why do we dream? These questions usually spark a lively discussion leading to the exchange of anecdotes, last night's dreams, and other personal information. But they are questions about the func­ tion of sleep and, interesting as they are, I shall have little more to say about them here. The questions that have concerned me deal instead with the timing of sleep. For those of us on a regular schedule, questions of timing may seem vacuous. We go to bed at night and get up in the morning, going through a cycle of sleeping and waking every 24 hours. Yet to a large extent, the cycle is imposed by the world around us.

  2. Effect of sleep deprivation on rhythms of clock gene expression and melatonin in humans.

    Science.gov (United States)

    Ackermann, Katrin; Plomp, Rosina; Lao, Oscar; Middleton, Benita; Revell, Victoria L; Skene, Debra J; Kayser, Manfred

    2013-08-01

    This study investigated the impact of sleep deprivation on the human circadian system. Plasma melatonin and cortisol levels and leukocyte expression levels of 12 genes were examined over 48 h (sleep vs. no-sleep nights) in 12 young males (mean±SD: 23±5 yrs). During one night of total sleep deprivation, BMAL1 expression was suppressed, the heat shock gene HSPA1B expression was induced, and the amplitude of the melatonin rhythm increased, whereas other high-amplitude clock gene rhythms (e.g., PER1-3, REV-ERBα) remained unaffected. These data suggest that the core clock mechanism in peripheral oscillators is compromised during acute sleep deprivation.

  3. Discharge Patterns of Human Genioglossus Motor Units during Arousal from Sleep

    Science.gov (United States)

    Wilkinson, Vanessa; Malhotra, Atul; Nicholas, Christian L.; Worsnop, Christopher; Jordan, Amy S.; Butler, Jane E.; Saboisky, Julian P.; Gandevia, Simon C.; White, David P.; Trinder, John

    2010-01-01

    Study Objectives: Single motor unit recordings of the human genioglossus muscle reveal motor units with a variety of discharge patterns. Integrated multiunit electromyographic recordings of genioglossus have demonstrated an abrupt increase in the muscle's activity at arousal from sleep. The aim of the present study was to determine the effect of arousal from sleep on the activity of individual motor units as a function of their particular discharge pattern. Design: Genioglossus activity was measured using intramuscular fine-wire electrodes inserted via a percutaneous approach. Arousals from sleep were identified using the ASDA criterion and the genioglossus electromyogram recordings analyzed for single motor unit activity. Setting: Sleep research laboratory. Participants: Sleep and respiratory data were collected in 8 healthy subjects (6 men). Measurements and Results: 138 motor units were identified during prearousalarousal sleep: 25% inspiratory phasic, 33% inspiratory tonic, 4% expiratory phasic, 3% expiratory tonic, and 35% tonic. At arousal from sleep inspiratory phasic units significantly increased the proportion of a breath over which they were active, but did not appreciably increase their rate of firing. 80 new units were identified at arousals, 75% were inspiratory, many of which were active for only 1 or 2 breaths. 22% of units active before arousal, particularly expiratory and tonic units, stopped at the arousal. Conclusions: Increased genioglossus muscle activity at arousal from sleep is primarily due to recruitment of inspiratory phasic motor units. Further, activity within the genioglossus motoneuron pool is reorganized at arousal as, in addition to recruitment, ∼20% of units active before arousals stopped firing. Citation: Wilkinson V; Malhotra A; Nicholas CL; Worsnop C; Jordan AS; Butler JE; Saboisky JP; Gandevia SC; White DP; Trinder J. Discharge patterns of human genioglossus motor units during arousal from sleep. SLEEP 2010;33(3):379-387. PMID

  4. Nocturnal ghrelin, ACTH, GH and cortisol secretion after sleep deprivation in humans.

    Science.gov (United States)

    Schüssler, P; Uhr, M; Ising, M; Weikel, J C; Schmid, D A; Held, K; Mathias, S; Steiger, A

    2006-09-01

    Ghrelin is an endogenous ligand of the growth hormone (GH) secretagogue (GHS) receptor. It is hypothesised to play a key role in energy balance stimulating food intake and body weight. Besides GH-releasing hormone (GHRH) and somatostatin, it is thought to be a regulating factor of GH release. Ghrelin also appears to be involved in sleep regulation. We showed recently that ghrelin promotes slow-wave sleep and the nocturnal release of GH, cortisol and prolactin in humans. Similarly, promotion of non-rapid-eye-movement (NREM) sleep was reported in mice after systemic ghrelin. If ghrelin is a factor that induces and/or maintains sleep, it should be enhanced after a period of sleep deprivation (SD). To clarify this issue, nocturnal ghrelin, GH, ACTH and cortisol plasma concentrations were determined and simultaneously sleep electroencephalogram (EEG) was recorded (2300-0700 h) during sleep before and after 1 night of total SD in 8 healthy subjects. Compared to baseline, ghrelin levels increased earlier by a non-significant trend, already before the beginning of recovery sleep. Further a non-significant trend occurred, suggesting higher ghrelin secretion in the first half of the night. The ghrelin maximum was found significantly earlier after SD than at baseline. GH secretion during the first half of the night and total night after SD were elevated. ACTH and cortisol were also elevated, which was most pronounced during the second half of the night. No effects of SD on the time of the maximum were found for GH, ACTH and cortisol. The increase in ACTH after SD is a novel finding. Whereas the effects of SD on ghrelin levels were relatively weak, our findings are in line with the hypothesis that ghrelin is a sleep-promoting factor in humans. Ghrelin may be involved in sleep promotion after SD.

  5. Auditory evoked responses upon awakening from sleep in human subjects.

    Science.gov (United States)

    Ferrara, M; De Gennaro, L; Ferlazzo, F; Curcio, G; Barattucci, M; Bertini, M

    2001-09-14

    The hypothesis that a state of hypoarousal upon awakening should lead to a decrease in amplitude and an increase in latency of the N1-P2 components of the Auditory Evoked Potentials (AEPs) as compared to presleep wakefulness levels, was evaluated after two nocturnal awakenings and after the final morning awakening from a 7.5-h night of sleep. The amplitude of the N1-P2 complex was reduced upon awakening as compared to presleep wakefulness levels, but only following the first nocturnal awakening, scheduled after the first 2 h of sleep. This result is interpreted as indicating a link between slow wave sleep amount, mainly present during the first part of the night, and lowered levels of brain activation upon awakening. The reaction times, recorded concomitantly to AEPs, were more sensitive to the negative effects of sleep inertia.

  6. Human Islet Amyloid Polypeptide N-Terminus Fragment Self-Assembly: Effect of Conserved Disulfide Bond on Aggregation Propensity

    Science.gov (United States)

    Ilitchev, Alexandre I.; Giammona, Maxwell J.; Do, Thanh D.; Wong, Amy G.; Buratto, Steven K.; Shea, Joan-Emma; Raleigh, Daniel P.; Bowers, Michael T.

    2016-06-01

    Amyloid formation by human islet amyloid polypeptide (hIAPP) has long been implicated in the pathogeny of type 2 diabetes mellitus (T2DM) and failure of islet transplants, but the mechanism of IAPP self-assembly is still unclear. Numerous fragments of hIAPP are capable of self-association into oligomeric aggregates, both amyloid and non-amyloid in structure. The N-terminal region of IAPP contains a conserved disulfide bond between cysteines at position 2 and 7, which is important to hIAPP's in vivo function and may play a role in in vitro aggregation. The importance of the disulfide bond in this region was probed using a combination of ion mobility-based mass spectrometry experiments, molecular dynamics simulations, and high-resolution atomic force microscopy imaging on the wildtype 1-8 hIAPP fragment, a reduced fragment with no disulfide bond, and a fragment with both cysteines at positions 2 and 7 mutated to serine. The results indicate the wildtype fragment aggregates by a different pathway than either comparison peptide and that the intact disulfide bond may be protective against aggregation due to a reduction of inter-peptide hydrogen bonding.

  7. Active reward processing during human sleep: insights from sleep-related eating disorder

    Directory of Open Access Journals (Sweden)

    Lampros ePerogamvros

    2012-11-01

    Full Text Available In this paper, we present two carefully documented cases of patients with sleep-related eating disorder (SRED, a parasomnia which is characterized by involuntary compulsive eating during the night and whose pathophysiology is not known. Using video-polysomnography and psychometric examination, we found that both patients present elevated novelty seeking and increased reward sensitivity on reward-related questionnaires. In light of new evidence on the mesolimbic dopaminergic implication in compulsive eating disorders, our findings suggest a role of an active reward system during sleep in the manifestation of SRED.

  8. Learning increases human electroencephalographic coherence during subsequent slow sleep oscillations

    OpenAIRE

    Mölle, Matthias; Marshall, Lisa; Gais, Steffen; Born, Jan

    2004-01-01

    Learning is assumed to induce specific changes in neuronal activity during sleep that serve the consolidation of newly acquired memories. To specify such changes, we measured electroencephalographic (EEG) coherence during performance on a declarative learning task (word pair associations) and subsequent sleep. Compared with a nonlearning control condition, learning performance was accompanied with a strong increase in coherence in several EEG frequency bands. During subsequent non-rapid eye m...

  9. Heterogeneity of arousals in human sleep: A stereo-electroencephalographic study.

    Science.gov (United States)

    Peter-Derex, Laure; Magnin, Michel; Bastuji, Hélène

    2015-12-01

    Wakefulness, non-rapid eye movement (NREM), and rapid eye movement (REM) sleep are characterized by specific brain activities. However, recent experimental findings as well as various clinical conditions (parasomnia, sleep inertia) have revealed the presence of transitional states. Brief intrusions of wakefulness into sleep, namely, arousals, appear as relevant phenomena to characterize how brain commutes from sleep to wakefulness. Using intra-cerebral recordings in 8 drug-resistant epileptic patients, we analyzed electroencephalographic (EEG) activity during spontaneous or nociceptive-induced arousals in NREM and REM sleep. Wavelet spectral analyses were performed to compare EEG signals during arousals, sleep, and wakefulness, simultaneously in the thalamus, and primary, associative, or high-order cortical areas. We observed that 1) thalamic activity during arousals is stereotyped and its spectral composition corresponds to a state in-between wakefulness and sleep; 2) patterns of cortical activity during arousals are heterogeneous, their manifold spectral composition being related to several factors such as sleep stages, cortical areas, arousal modality ("spontaneous" vs nociceptive-induced), and homeostasis; 3) spectral compositions of EEG signals during arousal and wakefulness differ from each other. Thus, stereotyped arousals at the thalamic level seem to be associated with different patterns of cortical arousals due to various regulation factors. These results suggest that the human cortex does not shift from sleep to wake in an abrupt binary way. Arousals may be considered more as different states of the brain than as "short awakenings." This phenomenon may reflect the mechanisms involved in the negotiation between two main contradictory functional necessities, preserving the continuity of sleep, and maintaining the possibility to react. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Dose-Dependent Model of Caffeine Effects on Human Vigilance during Total Sleep Deprivation

    Science.gov (United States)

    2014-05-20

    corresponding caffeine -free model estimates to assess the benefit of accounting for the effects of single caffeine doses of 100, 200, or 300 mg on performance in...directions. In other words, those subjects with the largest impairment from sleep loss showed the largest caffeine benefit (Landolt et al., 2012). This...Dose-dependent model of caffeine effects on human vigilance during total sleep deprivation Sridhar Ramakrishnan a, Srinivas Laxminarayan a, Nancy J

  11. Sleep-Wake Disturbances After Traumatic Brain Injury: Synthesis of Human and Animal Studies.

    Science.gov (United States)

    Sandsmark, Danielle K; Elliott, Jonathan E; Lim, Miranda M

    2017-05-01

    Sleep-wake disturbances following traumatic brain injury (TBI) are increasingly recognized as a serious consequence following injury and as a barrier to recovery. Injury-induced sleep-wake disturbances can persist for years, often impairing quality of life. Recently, there has been a nearly exponential increase in the number of primary research articles published on the pathophysiology and mechanisms underlying sleep-wake disturbances after TBI, both in animal models and in humans, including in the pediatric population. In this review, we summarize over 200 articles on the topic, most of which were identified objectively using reproducible online search terms in PubMed. Although these studies differ in terms of methodology and detailed outcomes; overall, recent research describes a common phenotype of excessive daytime sleepiness, nighttime sleep fragmentation, insomnia, and electroencephalography spectral changes after TBI. Given the heterogeneity of the human disease phenotype, rigorous translation of animal models to the human condition is critical to our understanding of the mechanisms and of the temporal course of sleep-wake disturbances after injury. Arguably, this is most effectively accomplished when animal and human studies are performed by the same or collaborating research programs. Given the number of symptoms associated with TBI that are intimately related to, or directly stem from sleep dysfunction, sleep-wake disorders represent an important area in which mechanistic-based therapies may substantially impact recovery after TBI. Published by Oxford University Press on behalf of Sleep Research Society (SRS) 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  12. Functional structure of spontaneous sleep slow oscillation activity in humans.

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    Danilo Menicucci

    Full Text Available BACKGROUND: During non-rapid eye movement (NREM sleep synchronous neural oscillations between neural silence (down state and neural activity (up state occur. Sleep Slow Oscillations (SSOs events are their EEG correlates. Each event has an origin site and propagates sweeping the scalp. While recent findings suggest a SSO key role in memory consolidation processes, the structure and the propagation of individual SSO events, as well as their modulation by sleep stages and cortical areas have not been well characterized so far. METHODOLOGY/PRINCIPAL FINDINGS: We detected SSO events in EEG recordings and we defined and measured a set of features corresponding to both wave shapes and event propagations. We found that a typical SSO shape has a transition to down state, which is steeper than the following transition from down to up state. We show that during SWS SSOs are larger and more locally synchronized, but less likely to propagate across the cortex, compared to NREM stage 2. Also, the detection number of SSOs as well as their amplitudes and slopes, are greatest in the frontal regions. Although derived from a small sample, this characterization provides a preliminary reference about SSO activity in healthy subjects for 32-channel sleep recordings. CONCLUSIONS/SIGNIFICANCE: This work gives a quantitative picture of spontaneous SSO activity during NREM sleep: we unveil how SSO features are modulated by sleep stage, site of origin and detection location of the waves. Our measures on SSOs shape indicate that, as in animal models, onsets of silent states are more synchronized than those of neural firing. The differences between sleep stages could be related to the reduction of arousal system activity and to the breakdown of functional connectivity. The frontal SSO prevalence could be related to a greater homeostatic need of the heteromodal association cortices.

  13. Involvement of cytokines in slow wave sleep.

    Science.gov (United States)

    Krueger, James M; Clinton, James M; Winters, Bradley D; Zielinski, Mark R; Taishi, Ping; Jewett, Kathryn A; Davis, Christopher J

    2011-01-01

    Cytokines such as tumor necrosis factor alpha (TNFα) and interleukin-1 beta (IL1β) play a role in sleep regulation in health and disease. TNFα or IL1β injection enhances non-rapid eye movement sleep. Inhibition of TNFα or IL1β reduces spontaneous sleep. Mice lacking TNFα or IL1β receptors sleep less. In normal humans and in multiple disease states, plasma levels of TNFα covary with EEG slow wave activity (SWA) and sleep propensity. Many of the symptoms induced by sleep loss, for example, sleepiness, fatigue, poor cognition, enhanced sensitivity to pain, are elicited by injection of exogenous TNFα or IL1β. IL1β or TNFα applied unilaterally to the surface of the cortex induces state-dependent enhancement of EEG SWA ipsilaterally, suggesting greater regional sleep intensity. Interventions such as unilateral somatosensory stimulation enhance localized sleep EEG SWA, blood flow, and somatosensory cortical expression of IL1β and TNFα. State oscillations occur within cortical columns. One such state shares properties with whole animal sleep in that it is dependent on prior cellular activity, shows homeostasis, and is induced by TNFα. Extracellular ATP released during neuro- and gliotransmission enhances cytokine release via purine type 2 receptors. An ATP agonist enhances sleep, while ATP antagonists inhibit sleep. Mice lacking the P2X7 receptor have attenuated sleep rebound responses after sleep loss. TNFα and IL1β alter neuron sensitivity by changing neuromodulator/neurotransmitter receptor expression, allowing the neuron to scale its activity to the presynaptic neurons. TNFα's role in synaptic scaling is well characterized. Because the sensitivity of the postsynaptic neuron is changed, the same input will result in a different network output signal and this is a state change. The top-down paradigm of sleep regulation requires intentional action from sleep/wake regulatory brain circuits to initiate whole-organism sleep. This raises unresolved

  14. Normal sleep and its neurophysiological regulation

    NARCIS (Netherlands)

    Hofman, W.F.; Talamini, L.M.; Watson, R.R.

    2015-01-01

    Normal sleep consists of two states: NREM (light and deep sleep) and REM, alternating in a cyclical pattern. The sleep/wake rhythm is regulated by two processes: the sleep propensity, building up during wake, and the circadian rhythm, imposed by the suprachiasmatic nucleus. The arousal pathways in

  15. A role for sleep in the processing of memory traces. Contribution of functional neuroimaging in humans.

    Science.gov (United States)

    Maquet, P

    2004-01-01

    Sleep is thought to participate in the consolidation of recent memory traces. We tested this hypothesis in humans, using functional neuroimaging (functional magnetic resonance imaging and positron emission tomography). First, following the training on a procedural visuo-motor learning task (pursuit task), total sleep deprivation on the first post-training night significantly deteriorates the gain in performance, which is usually observed after one complete night of sleep. In parallel, sleep deprivation hampers the changes in functional segregation and connectivity, which underpin the gain in performance usually observed in subjects allowed to sleep on the first post-training night. Second, following the training on an implicit memory task (probabilistic serial reaction time task), some brain areas are reactivated during REM sleep on the first post-training night. The reactivation was shown to be related to the processing of high-level material and to be modulated by the amount of learning achieved during the training session. These changes in activity do not involve isolated brain areas but entire macroscopic cortico-subcortical networks. Taken together, the results suggest an off-line processing of recent memory traces during sleep.

  16. A functional MRI study of the influence of sleep deprivation on digital memory in human brain

    Directory of Open Access Journals (Sweden)

    FAN Shuang-yi

    2013-05-01

    Full Text Available Background Working for long hours often leads to mental fatigue. There is evidence that mental fatigue is serious damage to cognitive function and behavior of the operator. Revealing the mechanism of continuous operation and sleep deprivation (SD on cognitive function, will help to combat the fatigue caused by continuous operation and to improve capacity of operators. This functional magnetic resonance imaging (fMRI study focused on the influence of sleep deprivation on digital memory in human brain. Methods Totally 6 healthy subjects underwent a digital memory encoding, maintenance and retrieval session during fMRI scanning before and after 48 h sleep deprivation. Results The digital memory test had the same error rate before and after sleep deprivation (P > 0.05, for all, but the reponse time of seven-number memory was longer after sleep deprivation (P = 0.005. During encoding trials decreased fMRI regions of significant activation between sleep control and sleep deprivation were in left parahippocampal gyrus Brodmann 30, left superior temporal gyrus Brodmann 42, left insular lobe Brodmann 41 and left frontal lobe Brodmann 6. During maintenance trials decreased fMRI regions of significant activation were at left superior temporal gyrus Brodmann 38, left middle temporal gyrus Brodmann 21, left parahippocampus and amygdaloid nucleus Brodmann 30, left middle frontal gyrus Brodmann 47, left lenticular nucleus and thalamus, right lenticular nucleus, left retrosplenial granular cortex Brodmann 30, right retrosplenial granular cortex Brodmann 30, bilateral cingulate gyrus Brodmann 24 and bilateral middle frontal gyrus, medial frontal gyrus Brodmann 6. During retrieval trials decreased fMRI regions of significantly positive activation were at bilateral hippocampus, right amygdaloid nucleus and inferior parietal lobule Brodmann 40, left precuneus Brodmann 19 and thalamus. Conclusion Different brain regions are activated at different stages of the

  17. Local modulation of human brain responses by circadian rhythmicity and sleep debt.

    Science.gov (United States)

    Muto, Vincenzo; Jaspar, Mathieu; Meyer, Christelle; Kussé, Caroline; Chellappa, Sarah L; Degueldre, Christian; Balteau, Evelyne; Shaffii-Le Bourdiec, Anahita; Luxen, André; Middleton, Benita; Archer, Simon N; Phillips, Christophe; Collette, Fabienne; Vandewalle, Gilles; Dijk, Derk-Jan; Maquet, Pierre

    2016-08-12

    Human performance is modulated by circadian rhythmicity and homeostatic sleep pressure. Whether and how this interaction is represented at the regional brain level has not been established. We quantified changes in brain responses to a sustained-attention task during 13 functional magnetic resonance imaging sessions scheduled across the circadian cycle, during 42 hours of wakefulness and after recovery sleep, in 33 healthy participants. Cortical responses showed significant circadian rhythmicity, the phase of which varied across brain regions. Cortical responses also significantly decreased with accrued sleep debt. Subcortical areas exhibited primarily a circadian modulation that closely followed the melatonin profile. These findings expand our understanding of the mechanisms involved in maintaining cognition during the day and its deterioration during sleep deprivation and circadian misalignment. Copyright © 2016, American Association for the Advancement of Science.

  18. Sabotaging the benefits of our own human capital: Work unit characteristics and sleep.

    Science.gov (United States)

    Barnes, Christopher M; Jiang, Kaifeng; Lepak, David P

    2016-02-01

    The strategic human capital literature indicates the importance of human capital to work unit performance. However, we argue that human capital only aids performance when it is translated into actions beneficial to the unit. We examine a set of common human capital leveraging characteristics (including the use of extended shifts, night shifts, shift flexibility, norms for work as a priority over sleep, and norms for constant connectivity) as factors that enhance the effect of human capital on human capital utilization. We also draw from the 2-process model of sleep regulation to examine how these characteristics undermine employee sleep, and thus weaken the link between human capital and work unit performance efficiency. Overall, we propose that human capital leveraging strategies initially enhance the effect of human capital on work unit performance, but over time weaken the effect of human capital on work unit performance efficiency. Thus, strategies intended to enhance the beneficial effect of human capital on work unit performance can end up doing the opposite. (c) 2016 APA, all rights reserved).

  19. Entrainment of the circadian clock in humans: mechanism and implications for sleep disorders.

    Directory of Open Access Journals (Sweden)

    David Metcalfe

    2007-01-01

    Full Text Available Humans exhibit behaviour and physiology controlled by a circadian clock. The circadian period is genetically determined and administered by a series of interlocked autoregulatory feedback loops largely in the suprachiasmatic nuclei of the hypothalamus. The phase of the clock is, however, synchronised by a number of external environmental cues such as light. A failure or change in any one of the requisite clock components may result in the onset of a long-term sleep disorder. This review discusses the mechanism regulating circadian physiology in humans and explores how disturbances of this mechanism may result in sleep pathologies.

  20. Serum Amyloid A Production Is Triggered by Sleep Deprivation in Mice and Humans: Is That the Link between Sleep Loss and Associated Comorbidities?

    Science.gov (United States)

    de Oliveira, Edson M.; Visniauskas, Bruna; Tufik, Sergio; Andersen, Monica L.; Chagas, Jair R.; Campa, Ana

    2017-01-01

    Serum amyloid A (SAA) was recently associated with metabolic endotoxemia, obesity and insulin resistance. Concurrently, insufficient sleep adversely affects metabolic health and is an independent predisposing factor for obesity and insulin resistance. In this study we investigated whether sleep loss modulates SAA production. The serum SAA concentration increased in C57BL/6 mice subjected to sleep restriction (SR) for 15 days or to paradoxical sleep deprivation (PSD) for 72 h. Sleep restriction also induced the upregulation of Saa1.1/Saa2.1 mRNA levels in the liver and Saa3 mRNA levels in adipose tissue. SAA levels returned to the basal range after 24 h in paradoxical sleep rebound (PSR). Metabolic endotoxemia was also a finding in SR. Increased plasma levels of SAA were also observed in healthy human volunteers subjected to two nights of total sleep deprivation (Total SD), returning to basal levels after one night of recovery. The observed increase in SAA levels may be part of the initial biochemical alterations caused by sleep deprivation, with potential to drive deleterious conditions such as metabolic endotoxemia and weight gain. PMID:28335560

  1. Graph Theoretical Analysis of BOLD Functional Connectivity during Human Sleep without EEG Monitoring.

    Science.gov (United States)

    Lv, Jun; Liu, Dongdong; Ma, Jing; Wang, Xiaoying; Zhang, Jue

    2015-01-01

    Functional brain networks of human have been revealed to have small-world properties by both analyzing electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI) time series. In our study, by using graph theoretical analysis, we attempted to investigate the changes of paralimbic-limbic cortex between wake and sleep states. Ten healthy young people were recruited to our experiment. Data from 2 subjects were excluded for the reason that they had not fallen asleep during the experiment. For each subject, blood oxygen level dependency (BOLD) images were acquired to analyze brain network, and peripheral pulse signals were obtained continuously to identify if the subject was in sleep periods. Results of fMRI showed that brain networks exhibited stronger small-world characteristics during sleep state as compared to wake state, which was in consistent with previous studies using EEG synchronization. Moreover, we observed that compared with wake state, paralimbic-limbic cortex had less connectivity with neocortical system and centrencephalic structure in sleep. In conclusion, this is the first study, to our knowledge, has observed that small-world properties of brain functional networks altered when human sleeps without EEG synchronization. Moreover, we speculate that paralimbic-limbic cortex organization owns an efficient defense mechanism responsible for suppressing the external environment interference when humans sleep, which is consistent with the hypothesis that the paralimbic-limbic cortex may be functionally disconnected from brain regions which directly mediate their interactions with the external environment. Our findings also provide a reasonable explanation why stable sleep exhibits homeostasis which is far less susceptible to outside world.

  2. Effect of conditioned stimulus exposure during slow wave sleep on fear memory extinction in humans.

    Science.gov (United States)

    He, Jia; Sun, Hong-Qiang; Li, Su-Xia; Zhang, Wei-Hua; Shi, Jie; Ai, Si-Zhi; Li, Yun; Li, Xiao-Jun; Tang, Xiang-Dong; Lu, Lin

    2015-03-01

    Repeated exposure to a neutral conditioned stimulus (CS) in the absence of a noxious unconditioned stimulus (US) elicits fear memory extinction. The aim of the current study was to investigate the effects of mild tone exposure (CS) during slow wave sleep (SWS) on fear memory extinction in humans. The healthy volunteers underwent an auditory fear conditioning paradigm on the experimental night, during which tones served as the CS, and a mild shock served as the US. They were then randomly assigned to four groups. Three groups were exposed to the CS for 3 or 10 min or an irrelevant tone (control stimulus, CtrS) for 10 min during SWS. The fourth group served as controls and was not subjected to any interventions. All of the subjects completed a memory test 4 h after SWS-rich stage to evaluate the effect on fear extinction. Moreover, we conducted similar experiments using an independent group of subjects during the daytime to test whether the memory extinction effect was specific to the sleep condition. Ninety-six healthy volunteers (44 males) aged 18-28 y. Participants exhibited undisturbed sleep during 2 consecutive nights, as assessed by sleep variables (all P > 0.05) from polysomnographic recordings and power spectral analysis. Participants who were re-exposed to the 10 min CS either during SWS and wakefulness exhibited attenuated fear responses (wake-10 min CS, P memory extinction without altering sleep profiles. © 2015 Associated Professional Sleep Societies, LLC.

  3. REM sleep, prefrontal theta, and the consolidation of human emotional memory.

    Science.gov (United States)

    Nishida, Masaki; Pearsall, Jori; Buckner, Randy L; Walker, Matthew P

    2009-05-01

    Both emotion and sleep are independently known to modulate declarative memory. Memory can be facilitated by emotion, leading to enhanced consolidation across increasing time delays. Sleep also facilitates offline memory processing, resulting in superior recall the next day. Here we explore whether rapid eye movement (REM) sleep, and aspects of its unique neurophysiology, underlie these convergent influences on memory. Using a nap paradigm, we measured the consolidation of neutral and negative emotional memories, and the association with REM-sleep electrophysiology. Subjects that napped showed a consolidation benefit for emotional but not neutral memories. The No-Nap control group showed no evidence of a consolidation benefit for either memory type. Within the Nap group, the extent of emotional memory facilitation was significantly correlated with the amount of REM sleep and also with right-dominant prefrontal theta power during REM. Together, these data support the role of REM-sleep neurobiology in the consolidation of emotional human memories, findings that have direct translational implications for affective psychiatric and mood disorders.

  4. Sleep complaints among Brazilian senior citizens from municipalities with different human development indices.

    Science.gov (United States)

    dos Santos, Ariene Angelini; Ceolim, Maria Filomena; Neri, Anita Liberalesso

    2012-01-01

    To compare the occurrence of sleep complaints among senior citizens resident in the local communities of two municipalities with differing Human Development Indices (HDIs): Campinas, State of São Paulo (IDH = 0.852) and Parnaíba, State of Piauí (IDH = 0.674). Descriptive study as part of the multicentric project going by the name of Frailty among Brazilian Senior Citizens (Fragilidade em Idosos Brasileiros--FIBRA). A total of 988 senior citizens were analysed, making use of a social and demographic questionnaire about sleep problems (Nottingham Health Profile); questions about naps (Minnesota Leisure Activity Questionnaire). The Chi-Square and Mann-Whitney tests were used in the analysis of the data, at a significance level of 5% (p<0.05). The chronologically advantaged individuals in Parnaíba showed a higher incidence of sleep complaints when compared to the senior citizens of Campinas. There was a significant association between municipality and the following variables: number of sleep complaints, non-restoring sleep, precocious awakening, difficulty in falling and staying asleep. The nursing staff must intervene in favour of the promotion of health with actions that either reduce or prevent these sleep-related problems.

  5. The influence of sleep on human hypothalamic-pituitary-adrenal (HPA) axis reactivity: A systematic review.

    Science.gov (United States)

    van Dalfsen, Jens H; Markus, C Rob

    2017-10-18

    Inadequate sleep is highly prevalent and known to decline both physical- and mental health. Literature suggests that altered functioning of the hypothalamic-pituitary-adrenal (HPA) axis might underlie this association. This assumption is mainly based on changes in basal neuroendocrine activity and it is of equal importance to elucidate whether sleep may also influence HPA stress responsiveness. The present review provides a complete outline of recent human studies that have investigated how different aspects of sleep influence cortisol reactivity to laboratory stress. From the available data it can be concluded that both objective and subjective decrements in sleep quality potentiate the stress reactivity of the HPA axis. On the contrary, normal variations in sleep duration do not seem to influence cortisol stress responsiveness whereas excessive daytime sleepiness is associated with a blunting of the cortisol response. Given its well-established health consequences, sensitization of the HPA axis might well be a crucial component linking inadequate sleep to stress-related pathology. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Millisecond flashes of light phase delay the human circadian clock during sleep

    OpenAIRE

    Zeitzer, Jamie M; Fisicaro, Ryan A.; Ruby, Norman F.; Heller, H. Craig

    2014-01-01

    The human circadian timing system is most sensitive to the phase shifting effects of light during the biological nighttime, a time at which humans are most typically asleep. The overlap of sleep with peak sensitivity to the phase shifting effects of light minimizes the effectiveness of using light as a countermeasure to circadian misalignment in humans. Most current light exposure treatments for such misalignment are mostly ineffective due to poor compliance and secondary changes that cause s...

  7. Circadian and sleep-dependent regulation of hormone release in humans

    Science.gov (United States)

    Czeisler, C. A.; Klerman, E. B.

    1999-01-01

    Daily oscillations characterize the release of nearly every hormone. The circadian pacemaker, located in the suprachiasmatic nucleus of the hypothalamus, generates circadian, approximately 24-hour rhythms in many physiologic functions. However, the observed hormonal oscillations do not simply reflect the output of this internal clock. Instead, daily hormonal profiles are the product of a complex interaction between the output of the circadian pacemaker, periodic changes in behavior, light exposure, neuroendocrine feedback mechanisms, gender, age, and the timing of sleep and wakefulness. The interaction of these factors can affect hormonal secretory pulse frequency and amplitude, with each endocrine system differentially affected by these factors. This chapter examines recent advances in understanding the effects on endocrine rhythms of a number of these factors. Sleep exerts a profound effect on endocrine secretion. Sleep is a dynamic process that is characterized by periodic changes in electrophysiologic activity. These electrophysiologic changes, which are used to mark the state and depth of sleep, are associated with periodic, short-term variations in hormonal levels. The secretion of hormones such as renin and human growth hormone are strongly influenced by sleep or wake state, while melatonin and cortisol levels are relatively unaffected by sleep or wake state. In addition, sleep is associated with changes in posture, behavior, and light exposure, each of which is known to affect endocrine secretion. Furthermore, the tight concordance of habitual sleep and wake times with certain circadian phases has made it difficult to distinguish sleep and circadian effects on these hormones. Specific protocols, designed to extract circadian and sleep information semi-independently, have been developed and have yielded important insights into the effects of these regulatory processes. These results may help to account for changes in endocrine rhythms observed in circadian

  8. Individual differences in the effects of mobile phone exposure on human sleep: rethinking the problem.

    Science.gov (United States)

    Loughran, Sarah P; McKenzie, Raymond J; Jackson, Melinda L; Howard, Mark E; Croft, Rodney J

    2012-01-01

    Mobile phone exposure-related effects on the human electroencephalogram (EEG) have been shown during both waking and sleep states, albeit with slight differences in the frequency affected. This discrepancy, combined with studies that failed to find effects, has led many to conclude that no consistent effects exist. We hypothesised that these differences might partly be due to individual variability in response, and that mobile phone emissions may in fact have large but differential effects on human brain activity. Twenty volunteers from our previous study underwent an adaptation night followed by two experimental nights in which they were randomly exposed to two conditions (Active and Sham), followed by a full-night sleep episode. The EEG spectral power was increased in the sleep spindle frequency range in the first 30 min of non-rapid eye movement (non-REM) sleep following Active exposure. This increase was more prominent in the participants that showed an increase in the original study. These results confirm previous findings of mobile phone-like emissions affecting the EEG during non-REM sleep. Importantly, this low-level effect was also shown to be sensitive to individual variability. Furthermore, this indicates that previous negative results are not strong evidence for a lack of an effect and, given the far-reaching implications of mobile phone research, we may need to rethink the interpretation of results and the manner in which research is conducted in this field. Copyright © 2011 Wiley Periodicals, Inc.

  9. Disrupted sleep without sleep curtailment induces sleepiness and cognitive dysfunction via the tumor necrosis factor-α pathway

    Directory of Open Access Journals (Sweden)

    Ramesh Vijay

    2012-05-01

    Full Text Available Abstract Background Sleepiness and cognitive dysfunction are recognized as prominent consequences of sleep deprivation. Experimentally induced short-term sleep fragmentation, even in the absence of any reductions in total sleep duration, will lead to the emergence of excessive daytime sleepiness and cognitive impairments in humans. Tumor necrosis factor (TNF-α has important regulatory effects on sleep, and seems to play a role in the occurrence of excessive daytime sleepiness in children who have disrupted sleep as a result of obstructive sleep apnea, a condition associated with prominent sleep fragmentation. The aim of this study was to examine role of the TNF-α pathway after long-term sleep fragmentation in mice. Methods The effect of chronic sleep fragmentation during the sleep-predominant period on sleep architecture, sleep latency, cognitive function, behavior, and inflammatory markers was assessed in C57BL/6 J and in mice lacking the TNF-α receptor (double knockout mice. In addition, we also assessed the above parameters in C57BL/6 J mice after injection of a TNF-α neutralizing antibody. Results Mice subjected to chronic sleep fragmentation had preserved sleep duration, sleep state distribution, and cumulative delta frequency power, but also exhibited excessive sleepiness, altered cognitive abilities and mood correlates, reduced cyclic AMP response element-binding protein phosphorylation and transcriptional activity, and increased phosphodiesterase-4 expression, in the absence of AMP kinase-α phosphorylation and ATP changes. Selective increases in cortical expression of TNF-α primarily circumscribed to neurons emerged. Consequently, sleepiness and cognitive dysfunction were absent in TNF-α double receptor knockout mice subjected to sleep fragmentation, and similarly, treatment with a TNF-α neutralizing antibody abrogated sleep fragmentation-induced learning deficits and increases in sleep propensity. Conclusions Taken together

  10. Impaired insulin signaling in human adipocytes after experimental sleep restriction: a randomized, crossover study.

    Science.gov (United States)

    Broussard, Josiane L; Ehrmann, David A; Van Cauter, Eve; Tasali, Esra; Brady, Matthew J

    2012-10-16

    Insufficient sleep increases the risk for insulin resistance, type 2 diabetes, and obesity, suggesting that sleep restriction may impair peripheral metabolic pathways. Yet, a direct link between sleep restriction and alterations in molecular metabolic pathways in any peripheral human tissue has not been shown. To determine whether sleep restriction results in reduced insulin sensitivity in subcutaneous fat, a peripheral tissue that plays a pivotal role in energy metabolism and balance. Randomized, 2-period, 2-condition, crossover clinical study. University of Chicago Clinical Resource Center. Seven healthy adults (1 woman, 6 men) with a mean age of 23.7 years (SD, 3.8) and mean body mass index of 22.8 kg/m(2) (SD, 1.6). Four days of 4.5 hours in bed or 8.5 hours in bed under controlled conditions of caloric intake and physical activity. Adipocytes collected from subcutaneous fat biopsy samples after normal and restricted sleep conditions were exposed to incremental insulin concentrations. The ability of insulin to increase levels of phosphorylated Akt (pAkt), a crucial step in the insulin-signaling pathway, was assessed. Total Akt (tAkt) served as a loading control. The insulin concentration for the half-maximal stimulation of the pAkt-tAkt ratio was used as a measure of cellular insulin sensitivity. Total body insulin sensitivity was assessed using a frequently sampled intravenous glucose tolerance test. The insulin concentration for the half-maximal pAkt-tAkt response was nearly 3-fold higher (mean, 0.71 nM [SD, 0.27] vs. 0.24 nM [SD, 0.24]; P = 0.01; mean difference, 0.47 nM [SD, 0.33]; P = 0.01), and the total area under the receiver-operating characteristic curve of the pAkt-tAkt response was 30% lower (P = 0.01) during sleep restriction than during normal sleep. A reduction in total body insulin sensitivity (P = 0.02) paralleled this impaired cellular insulin sensitivity. This was a single-center study with a small sample size. Sleep restriction results in an

  11. Sleep-deprivation effect on human performance: a meta-analysis approach

    Energy Technology Data Exchange (ETDEWEB)

    Candice D. Griffith; Candice D. Griffith; Sankaran Mahadevan

    2006-05-01

    Human fatigue is hard to define since there is no direct measure of fatigue, much like stress. Instead fatigue must be inferred from measures that are affected by fatigue. One such measurable output affected by fatigue is reaction time. In this study the relationship of reaction time to sleep deprivation is studied. These variables were selected because reaction time and hours of sleep deprivation are straightforward characteristics of fatigue to begin the investigation of fatigue effects on performance. Meta-analysis, a widely used procedure in medical and psychological studies, is applied to the variety of fatigue literature collected from various fields in this study. Meta-analysis establishes a procedure for coding and analyzing information from various studies to compute an effect size. In this research the effect size reported is the difference between standardized means, and is found to be -0.6341, implying a strong relationship between sleep deprivation and performance degradation.

  12. Sex differences in light sensitivity impact on brightness perception, vigilant attention and sleep in humans.

    Science.gov (United States)

    Chellappa, Sarah L; Steiner, Roland; Oelhafen, Peter; Cajochen, Christian

    2017-10-27

    Artificial light endows a "round-the-clock", 24-h/7-d society. Chronic exposure to light at night contributes to health hazards for humans, including disorders of sleep. Yet the influence of inter-individual traits, such as sex-differences, on light sensitivity remains to be established. Here we investigated potential sex-differences to evening light exposure of 40 lx at 6500 K (blue-enriched) or at 2500 K (non-blue-enriched), and their impact on brightness perception, vigilant attention and sleep physiology. In contrast to women, men had higher brightness perception and faster reaction times in a sustained attention task during blue-enriched light than non-blue-enriched. After blue-enriched light exposure, men had significantly higher all-night frontal NREM sleep slow-wave activity (SWA: 2-4 Hz), than women, particularly during the beginning of the sleep episode. Furthermore, brightness perception during blue-enriched light significantly predicted men's improved sustained attention performance and increased frontal NREM SWA. Our data indicate that, in contrast to women, men show a stronger response to blue-enriched light in the late evening even at very low light levels (40lux), as indexed by increased vigilant attention and sleep EEG hallmarks. Collectively, the data indicate that sex differences in light sensitivity might play a key role for ensuring the success of individually-targeted light interventions.

  13. A control system formulation of the mechanism that controls the secretions of serum group hormone in humans during sleep

    Science.gov (United States)

    Howard, J. C.; Young, D. R.

    1975-01-01

    Plasma growth hormone concentrations during sleep were determined experimentally. An elevated level of plasma growth hormone was observed during the initial phase of sleep and remained elevated for approximately 3 hr before returning to the steady-state level. Moreover, subsequent to a prolonged interruption of sleep, of the order of 2-3 hr, an elevated level of plasma growth hormone was again observed during the initial phase of resumed sleep. A control system formulation of the mechanism that controls the secretions of serum growth hormone in humans was used to account for the growth hormone responses observed.

  14. TRANSLATION OF BRAIN ACTIVITY INTO SLEEP

    OpenAIRE

    Krueger, James M.

    2012-01-01

    Cytokines including tumor necrosis factor alpha (TNF) play a role in sleep regulation in health and disease. Hypothalamic and cerebral cortical levels of TNF mRNA or TNF protein have diurnal variations with higher levels associated with greater sleep propensity. Sleep loss is associated with enhanced brain TNF. Central or systemic TNF injections enhance sleep. Inhibition of TNF using the soluble TNF receptor, or anti-TNF antibodies, or a TNF siRNA reduces spontaneous sleep. Mice lacking the T...

  15. [Propensity score matching in SPSS].

    Science.gov (United States)

    Huang, Fuqiang; DU, Chunlin; Sun, Menghui; Ning, Bing; Luo, Ying; An, Shengli

    2015-11-01

    To realize propensity score matching in PS Matching module of SPSS and interpret the analysis results. The R software and plug-in that could link with the corresponding versions of SPSS and propensity score matching package were installed. A PS matching module was added in the SPSS interface, and its use was demonstrated with test data. Score estimation and nearest neighbor matching was achieved with the PS matching module, and the results of qualitative and quantitative statistical description and evaluation were presented in the form of a graph matching. Propensity score matching can be accomplished conveniently using SPSS software.

  16. Risk propensity assessment in military special operations.

    Science.gov (United States)

    Sicard, B; Jouve, E; Blin, O

    2001-10-01

    Risk taking, decision making, and stress factors are strongly associated in military operations. The authors used the Bond and Lader mood and alertness scale and a new scale, Evaluation of Risks (EVAR), to assess risk proneness in a maritime counter-terrorism exercise. EVAR items are distributed among five factors: self-control, danger seeking, energy, impulsiveness, and invincibility. In the study, 10 pilots were submitted to strenuous night flights with limited sleep deprivation. Compared with baseline data, pilots reported an increase in impulsiveness, whereas EVAR factors were consistent in a control group composed of 9 navy crew member. Correlations were observed between mood and alertness and risk factors. These results illustrate how EVAR can be used to evaluate change in risk proneness in individuals submitted to various stressors. But further studies are required to weigh stress factors and environmental conditions in risk propensity with a larger population of various age and personality traits.

  17. Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans. : Phase Angle of Entrainment in Humans

    OpenAIRE

    Wright, Kenneth,; Gronfier, Claude; Duffy, Jeanne,; Czeisler, Charles,

    2005-01-01

    International audience; The internal circadian clock and sleep-wake homeostasis regulate the timing of human brain function, physiology, and behavior so that wakefulness and its associated functions are optimal during the solar day and that sleep and its related functions are optimal at night. The maintenance of a normal phase relationship between the internal circadian clock, sleep-wake homeostasis, and the light-dark cycle is crucial for optimal neurobehavioral and physiological function. H...

  18. Frontal predominance of a relative increase in sleep delta and theta EEG activity after sleep loss in humans

    Science.gov (United States)

    Cajochen, C.; Foy, R.; Dijk, D. J.; Czeisler, C. A. (Principal Investigator)

    1999-01-01

    The effect of sleep deprivation (40 h) on topographic and temporal aspects of electroencephalographic (EEG) activity during sleep was investigated by all night spectral analysis in six young volunteers. The sleep-deprivation-induced increase of EEG power density in the delta and theta frequencies (1-7 Hz) during nonREM sleep, assessed along the antero-posterior axis (midline: Fz, Cz, Pz, Oz), was significantly larger in the more frontal derivations (Fz, Cz) than in the more parietal derivations (Pz, Oz). This frequency-specific frontal predominance was already present in the first 30 min of recovery sleep, and dissipated in the course of the 8-h sleep episode. The data demonstrate that the enhancement of slow wave EEG activity during sleep following extended wakefulness is most pronounced in frontal cortical areas.

  19. Sleep quality, posttraumatic stress, depression, and human errors in train drivers: a population-based nationwide study in South Korea.

    Science.gov (United States)

    Jeon, Hong Jin; Kim, Ji-Hae; Kim, Bin-Na; Park, Seung Jin; Fava, Maurizio; Mischoulon, David; Kang, Eun-Ho; Roh, Sungwon; Lee, Dongsoo

    2014-12-01

    Human error is defined as an unintended error that is attributable to humans rather than machines, and that is important to avoid to prevent accidents. We aimed to investigate the association between sleep quality and human errors among train drivers. Cross-sectional. Population-based. A sample of 5,480 subjects who were actively working as train drivers were recruited in South Korea. The participants were 4,634 drivers who completed all questionnaires (response rate 84.6%). None. The Pittsburgh Sleep Quality Index (PSQI), the Center for Epidemiologic Studies Depression Scale (CES-D), the Impact of Event Scale-Revised (IES-R), the State-Trait Anxiety Inventory (STAI), and the Korean Occupational Stress Scale (KOSS). Of 4,634 train drivers, 349 (7.5%) showed more than one human error per 5 y. Human errors were associated with poor sleep quality, higher PSQI total scores, short sleep duration at night, and longer sleep latency. Among train drivers with poor sleep quality, those who experienced severe posttraumatic stress showed a significantly higher number of human errors than those without. Multiple logistic regression analysis showed that human errors were significantly associated with poor sleep quality and posttraumatic stress, whereas there were no significant associations with depression, trait and state anxiety, and work stress after adjusting for age, sex, education years, marital status, and career duration. Poor sleep quality was found to be associated with more human errors in train drivers, especially in those who experienced severe posttraumatic stress. © 2014 Associated Professional Sleep Societies, LLC.

  20. Wavelet package frequency-band energy ratios of human EEG signals in sleeping

    Science.gov (United States)

    Wang, Li; Han, Qingpeng; Wang, Ping; Wen, Bangchun

    2005-12-01

    Human EEG (Electroencephalogram) signals, including 4 rhythms i.e. δ, θ, α, β, are typically nonlinear. They just coincide with different human sleeping states. The wavelet package decomposition and reconstruction techniques are firstly introduced in order to analyze the nonlinear EEG. A 6 level decomposition of EEG was achieved with "db20" as the mother wavelet, and the above 4 rhythms were combined with specialized 8 frequency sub-bands obtained in wavelet package transform. The four frequency band energy ratios, with normalized values, were calculated from the reconstructed signals. These frequency band energy ratios are used as quantify estimation indexes for human sleeping states. The experimental results confirm the proposed method to be effective.

  1. Divergent cortical generators of MEG and EEG during human sleep spindles suggested by distributed source modeling.

    Science.gov (United States)

    Dehghani, Nima; Cash, Sydney S; Chen, Chih C; Hagler, Donald J; Huang, Mingxiong; Dale, Anders M; Halgren, Eric

    2010-07-07

    Sleep spindles are approximately 1-second bursts of 10-15 Hz activity, occurring during normal stage 2 sleep. In animals, sleep spindles can be synchronous across multiple cortical and thalamic locations, suggesting a distributed stable phase-locked generating system. The high synchrony of spindles across scalp EEG sites suggests that this may also be true in humans. However, prior MEG studies suggest multiple and varying generators. We recorded 306 channels of MEG simultaneously with 60 channels of EEG during naturally occurring spindles of stage 2 sleep in 7 healthy subjects. High-resolution structural MRI was obtained in each subject, to define the shells for a boundary element forward solution and to reconstruct the cortex providing the solution space for a noise-normalized minimum norm source estimation procedure. Integrated across the entire duration of all spindles, sources estimated from EEG and MEG are similar, diffuse and widespread, including all lobes from both hemispheres. However, the locations, phase and amplitude of sources simultaneously estimated from MEG versus EEG are highly distinct during the same spindles. Specifically, the sources estimated from EEG are highly synchronous across the cortex, whereas those from MEG rapidly shift in phase, hemisphere, and the location within the hemisphere. The heterogeneity of MEG sources implies that multiple generators are active during human sleep spindles. If the source modeling is correct, then EEG spindles are generated by a different, diffusely synchronous system. Animal studies have identified two thalamo-cortical systems, core and matrix, that produce focal or diffuse activation and thus could underlie MEG and EEG spindles, respectively. Alternatively, EEG spindles could reflect overlap at the sensors of the same sources as are seen from the MEG. Although our results generally match human intracranial recordings, additional improvements are possible and simultaneous intra- and extra-cranial measures

  2. Divergent cortical generators of MEG and EEG during human sleep spindles suggested by distributed source modeling.

    Directory of Open Access Journals (Sweden)

    Nima Dehghani

    2010-07-01

    Full Text Available Sleep spindles are approximately 1-second bursts of 10-15 Hz activity, occurring during normal stage 2 sleep. In animals, sleep spindles can be synchronous across multiple cortical and thalamic locations, suggesting a distributed stable phase-locked generating system. The high synchrony of spindles across scalp EEG sites suggests that this may also be true in humans. However, prior MEG studies suggest multiple and varying generators.We recorded 306 channels of MEG simultaneously with 60 channels of EEG during naturally occurring spindles of stage 2 sleep in 7 healthy subjects. High-resolution structural MRI was obtained in each subject, to define the shells for a boundary element forward solution and to reconstruct the cortex providing the solution space for a noise-normalized minimum norm source estimation procedure. Integrated across the entire duration of all spindles, sources estimated from EEG and MEG are similar, diffuse and widespread, including all lobes from both hemispheres. However, the locations, phase and amplitude of sources simultaneously estimated from MEG versus EEG are highly distinct during the same spindles. Specifically, the sources estimated from EEG are highly synchronous across the cortex, whereas those from MEG rapidly shift in phase, hemisphere, and the location within the hemisphere.The heterogeneity of MEG sources implies that multiple generators are active during human sleep spindles. If the source modeling is correct, then EEG spindles are generated by a different, diffusely synchronous system. Animal studies have identified two thalamo-cortical systems, core and matrix, that produce focal or diffuse activation and thus could underlie MEG and EEG spindles, respectively. Alternatively, EEG spindles could reflect overlap at the sensors of the same sources as are seen from the MEG. Although our results generally match human intracranial recordings, additional improvements are possible and simultaneous intra- and extra

  3. Mammalian sleep

    Science.gov (United States)

    Staunton, Hugh

    2005-05-01

    This review examines the biological background to the development of ideas on rapid eye movement sleep (REM sleep), so-called paradoxical sleep (PS), and its relation to dreaming. Aspects of the phenomenon which are discussed include physiological changes and their anatomical location, the effects of total and selective sleep deprivation in the human and animal, and REM sleep behavior disorder, the latter with its clinical manifestations in the human. Although dreaming also occurs in other sleep phases (non-REM or NREM sleep), in the human, there is a contingent relation between REM sleep and dreaming. Thus, REM is taken as a marker for dreaming and as REM is distributed ubiquitously throughout the mammalian class, it is suggested that other mammals also dream. It is suggested that the overall function of REM sleep/dreaming is more important than the content of the individual dream; its function is to place the dreamer protagonist/observer on the topographical world. This has importance for the developing infant who needs to develop a sense of self and separateness from the world which it requires to navigate and from which it is separated for long periods in sleep. Dreaming may also serve to maintain a sense of ‘I’ness or “self” in the adult, in whom a fragility of this faculty is revealed in neurological disorders.

  4. Intranasal insulin decreases circulating cortisol concentrations during early sleep in elderly humans.

    Science.gov (United States)

    Thienel, Matthias; Wilhelm, Ines; Benedict, Christian; Born, Jan; Hallschmid, Manfred

    2017-06-01

    Aging is associated with increases in hypothalamic-pituitary-adrenal (HPA) axis activity that can predispose to metabolic and cognitive impairments. We investigated in elderly and young subjects whether intranasal insulin administration to the human brain reduces early-sleep nadir concentrations of adrenocorticotropin and cortisol, that is, indicators of baseline HPA axis activity. In within-subject comparisons, intranasal insulin (160 IU) or placebo was administered to 14 elderly (mean age 70.0 years) and 30 young (23.6 years) healthy subjects before bedtime. Sleep was polysomnographically assessed and blood samples were repeatedly collected. Elderly compared with young participants displayed increased early-sleep cortisol concentrations (p Insulin administration reduced cortisol levels between 2300 hours and 0020 hours in the elderly (p = 0.03) but not young participants (p = 0.56; p = 0.003 for interaction). Findings indicate that central nervous insulin acts as an inhibitory signal in basal HPA axis activity regulation and suggest that intranasal insulin may normalize sleep-associated stress axis activity in older age. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  5. Bone Turnover Markers After Sleep Restriction and Circadian Disruption: A Mechanism for Sleep-Related Bone Loss in Humans.

    Science.gov (United States)

    Swanson, Christine M; Shea, Steven A; Wolfe, Pamela; Cain, Sean W; Munch, Mirjam; Vujovic, Nina; Czeisler, Charles A; Buxton, Orfeu M; Orwoll, Eric S

    2017-10-01

    Sleep abnormalities are associated with low bone mineral density. Underlying mechanisms are unknown. Investigate the impact of sleep restriction with circadian disruption on bone biomarkers. Intervention study. Four bone biomarkers [C-terminal cross-linked telopeptide of type I collagen (CTX) = bone resorption, N-terminal propeptide of type I procollagen (P1NP) = bone formation, sclerostin and fibroblast growth factor 23 = osteocyte function] were measured in bihourly serum samples over 24 hours at baseline and after ∼3 weeks of sleep restriction (5.6 hours sleep/24 hours) with concurrent circadian disruption (recurring 28-hour "day" in dim light) in 10 men (age groups: 20 to 27 years, n = 6; 55 to 65 years, n = 4). The effects of sleep/circadian disruption and age on bone biomarker levels were evaluated using maximum likelihood estimation in a mixed model for repeated measures. P1NP levels were lower after intervention compared with baseline (P sleep restriction can lead to an uncoupling of bone turnover wherein bone formation is decreased but bone resorption is unchanged. Circadian disruption and sleep restriction may be most detrimental to bone in early adulthood.

  6. Coupling of Thalamocortical Sleep Oscillations Are Important for Memory Consolidation in Humans.

    Directory of Open Access Journals (Sweden)

    Mohammad Niknazar

    Full Text Available Sleep, specifically non-rapid eye movement (NREM sleep, is thought to play a critical role in the consolidation of recent memories. Two main oscillatory activities observed during NREM, cortical slow oscillations (SO, 0.5-1.0 Hz and thalamic spindles (12-15 Hz, have been shown to independently correlate with memory improvement. Yet, it is not known how these thalamocortical events interact, or the significance of this interaction, during the consolidation process. Here, we found that systemic administration of the GABAergic drug (zolpidem increased both the phase-amplitude coupling between SO and spindles, and verbal memory improvement in humans. These results suggest that thalamic spindles that occur during transitions to the cortical SO Up state are optimal for memory consolidation. Our study predicts that the timely interactions between cortical and thalamic events during consolidation, contribute to memory improvement and is mediated by the level of inhibitory neurotransmission.

  7. Diagnostic value of sleep stage dissociation as visualized on a 2-dimensional sleep state space in human narcolepsy.

    Science.gov (United States)

    Olsen, Anders Vinther; Stephansen, Jens; Leary, Eileen; Peppard, Paul E; Sheungshul, Hong; Jennum, Poul Jørgen; Sorensen, Helge; Mignot, Emmanuel

    2017-04-15

    Type 1 narcolepsy (NT1) is characterized by symptoms believed to represent Rapid Eye Movement (REM) sleep stage dissociations, occurrences where features of wake and REM sleep are intermingled, resulting in a mixed state. We hypothesized that sleep stage dissociations can be objectively detected through the analysis of nocturnal Polysomnography (PSG) data, and that those affecting REM sleep can be used as a diagnostic feature for narcolepsy. A Linear Discriminant Analysis (LDA) model using 38 features extracted from EOG, EMG and EEG was used in control subjects to select features differentiating wake, stage N1, N2, N3 and REM sleep. Sleep stage differentiation was next represented in a 2D projection. Features characteristic of sleep stage differences were estimated from the residual sleep stage probability in the 2D space. Using this model we evaluated PSG data from NT1 and non-narcoleptic subjects. An LDA classifier was used to determine the best separation plane. This method replicates the specificity/sensitivity from the training set to the validation set better than many other methods. Eight prominent features could differentiate narcolepsy and controls in the validation dataset. Using a composite measure and a specificity cut off 95% in the training dataset, sensitivity was 43%. Specificity/sensitivity was 94%/38% in the validation set. Using hypersomnia subjects, specificity/sensitivity was 84%/15%. Analyzing treated narcoleptics the specificity/sensitivity was 94%/10%. Sleep stage dissociation can be used for the diagnosis of narcolepsy. However the use of some medications and presence of undiagnosed hypersomnolence patients impacts the result. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Evidence of subthalamic PGO-like waves during REM sleep in humans: a deep brain polysomnographic study.

    Science.gov (United States)

    Fernández-Mendoza, Julio; Lozano, Beatriz; Seijo, Fernando; Santamarta-Liébana, Elena; Ramos-Platón, Maria José; Vela-Bueno, Antonio; Fernández-González, Fernando

    2009-09-01

    The aim of this study was to examine whether the subthalamic nucleus (STN) plays a role in the transmission of PGO-like waves during REM sleep in humans. Simultaneous recordings from deep brain electrodes to record local field potentials (LFPs), and standard polysomnography to ascertain sleep/wake states. Main Hospital, department of clinical neurophysiology sleep laboratory. 12 individuals with Parkinson's disease, with electrodes implanted in the STN; and, as a control for localization purposes, 4 cluster headache patients with electrodes implanted in the posterior hypothalamus. All subjects underwent functional neurosurgery for implantation of deep brain stimulation electrodes. Sharp, polarity-reversed LFPs were recorded within the STN during REM sleep in humans. These subthalamic PGO-like waves (2-3 Hz, 80-200 pV, and 300-500 msec) appeared during REM epochs as singlets or in clusters of 3-13 waves. During the pre-REM period, subthalamic PGO-like waves were temporally related to drops in the submental electromyogram and/or onset of muscular atonia. Clusters of PGO-like waves occurred typically before and during the bursts of rapid eye movements and were associated with an enhancement in fast (15-35 Hz) subthalamic oscillatory activity. Subthalamic PGO-like waves can be recorded during pre-REM and REM sleep in humans. Our data suggest that the STN may play an active role in an ascending activating network implicated in the transmission of PGO waves during REM sleep in humans.

  9. Sleep deprivation impairs performance in the 5-choice continuous performance test: similarities between humans and mice.

    Science.gov (United States)

    van Enkhuizen, Jordy; Acheson, Dean; Risbrough, Victoria; Drummond, Sean; Geyer, Mark A; Young, Jared W

    2014-03-15

    Several groups undergo extended periods without sleep due to working conditions or mental illness. Such sleep deprivation (SD) can deleteriously affect attentional processes and disrupt work and family functioning. Understanding the biological underpinnings of SD effects may assist in developing sleep therapies and cognitive enhancers. Utilizing cross-species tests of attentional processing in humans and rodents would aid in mechanistic studies examining SD-induced inattention. We assessed the effects of 36h of: (1) Total SD (TSD) in healthy male and female humans (n=50); and (2) REM SD (RSD) in male C57BL/6 mice (n=26) on performance in the cross-species 5-choice continuous performance test (5C-CPT). The 5C-CPT includes target trials on which subjects were required to respond and non-target trials on which subjects were required to inhibit from responding. TSD-induced effects on human psychomotor vigilance test (PVT) were also examined. Effects of SD were also examined on mice split into good and poor performance groups based on pre-deprivation scores. In the human 5C-CPT, TSD decreased hit rate and vigilance with trend-level effects on accuracy. In the PVT, TSD slowed response times and increased lapses. In the mouse 5C-CPT, RSD reduced accuracy and hit rate with trend-level effects on vigilance, primarily in good performers. In conclusion, SD induced impaired 5C-CPT performance in both humans and mice and validates the 5C-CPT as a cross-species translational task. The 5C-CPT can be used to examine mechanisms underlying SD-induced deficits in vigilance and assist in testing putative cognitive enhancers. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Evening light exposure to computer screens disrupts human sleep, biological rhythms, and attention abilities.

    Science.gov (United States)

    Green, A; Cohen-Zion, M; Haim, A; Dagan, Y

    2017-01-01

    The use of electronic devices with light-emitting screens has increased exponentially in the last decade. As a result, humans are almost continuously exposed to unintentional artificial light. We explored the independent and combined effects of two aspects of screen illumination, light wavelength, and intensity, on sleep, its biological regulation, and related functional outcomes. The 2 × 2 repeated-measure design included two independent variables: screen light intensity (low ([LI] versus high [HI]) and wavelength (short [SWL] versus long [LWL]). Nineteen participants (11F, 8M; mean age 24.3 [±2.8] years) underwent four light conditions, LI/SWL, HI/SWL, LI/LWL, and HI/LWL, in counterbalanced order. Each light exposure lasted for two hours (21:00-23:00), following which participants underwent an overnight polysomnography. On each experimental night, oral temperature and urine samples (for melatonin analysis) were collected at multiple time points. Each morning, participants filled out questionnaires and conducted a computerized attention task. Irrespective of light intensity, SWL illumination significantly disrupted sleep continuity and architecture and led to greater self-reported daytime sleepiness. SWL light also altered biological rhythms, subduing the normal nocturnal decline in body temperature and dampening nocturnal melatonin secretion. Light intensity seemed to independently affect sleep as well, but to a lesser degree. Both light intensity and wavelength negatively affected morning attention. In sum, light wavelength seems to have a greater influence than light intensity on sleep and a wide-range of biological and behavioral functions. Given the widespread use of electronic devices today, our findings suggest that screen light exposure at evening may have detrimental effects on human health and performance.

  11. Density and Frequency Caudo-Rostral Gradients of Sleep Spindles Recorded in the Human Cortex

    Science.gov (United States)

    Peter-Derex, Laure; Comte, Jean-Christophe; Mauguière, François; Salin, Paul A.

    2012-01-01

    Study Objective: This study aims at providing a quantitative description of intrinsic spindle frequency and density (number of spindles/min) in cortical areas using deep intracerebral recordings in humans. Patients or Participants: Thirteen patients suffering from pharmaco-resistant focal epilepsy and investigated through deep intracortical EEG in frontal, parietal, temporal, occipital, insular, and limbic cortices including the hippocampus were included. Methods: Spindle waves were detected from the ongoing EEG during slow wave sleep (SWS) by performing a time-frequency analysis on filtered signals (band-pass filter: 10-16 Hz). Then, spindle intrinsic frequency was determined using a fast Fourier transform, and spindle density (number of spindles per minute) was computed. Results: Firstly, we showed that sleep spindles were recorded in all explored cortical areas, except temporal neocortex. In particular, we observed the presence of spindles during SWS in areas such as the insular cortex, medial parietal cortex, occipital cortex, and cingulate gyrus. Secondly, we demonstrated that both spindle frequency and density smoothly change along the caudo-rostral axis, from fast frequent posterior spindles to slower and less frequent anterior spindles. Thirdly, we identified the presence of spindle frequency oscillations in the hippocampus and the entorhinal cortex. Conclusions: Spindling activity is widespread among cortical areas, which argues for the fundamental role of spindles in cortical functions. Mechanisms of caudo-rostral gradient modulation in spindle frequency and density may result from a complex interplay of intrinsic properties and extrinsic modulation of thalamocortical and corticothalamic neurons. Citation: Peter-Derex L; Comte JC; Mauguière F; Salin PA. Density and frequency caudo-rostral gradients of sleep spindles recorded in the human cortex. SLEEP 2012;35(1):69-79. PMID:22215920

  12. Gender differences in entrepreneurial propensity

    NARCIS (Netherlands)

    Koellinger, P.; Minniti, M.; Schade, C.

    2013-01-01

    Using data from representative population surveys in 17 countries, we find that the lower rate of female business ownership is primarily due to women's lower propensity to start businesses rather than to differences in survival rates across genders. We show that women are less confident in their

  13. Gender Differences in Entrepreneurial Propensity

    NARCIS (Netherlands)

    Ph.D. Koellinger (Philipp); M. Minniti (Maria); C. Schade (Christian)

    2013-01-01

    textabstractUsing data from representative population surveys in 17 countries, we find that the lower rate of female business ownership is primarily due to women's lower propensity to start businesses rather than to differences in survival rates across genders. We show that women are less confident

  14. Diagnostic value of sleep stage dissociation as visualized on a 2-dimensional sleep state space in human narcolepsy

    DEFF Research Database (Denmark)

    Olsen, Anders Vinther; Stephansen, Jens; Leary, Eileen B.

    2017-01-01

    Type 1 narcolepsy (NT1) is characterized by symptoms believed to represent Rapid Eye Movement (REM) sleep stage dissociations, occurrences where features of wake and REM sleep are intermingled, resulting in a mixed state. We hypothesized that sleep stage dissociations can be objectively detected...... through the analysis of nocturnal Polysomnography (PSG) data, and that those affecting REM sleep can be used as a diagnostic feature for narcolepsy. A Linear Discriminant Analysis (LDA) model using 38 features extracted from EOG, EMG and EEG was used in control subjects to select features differentiating......-narcoleptic subjects. An LDA classifier was used to determine the best separation plane. This method replicates the specificity/sensitivity from the training set to the validation set better than many other methods. Eight prominent features could differentiate narcolepsy and controls in the validation dataset. Using...

  15. REM sleep characteristics of nightmare sufferers before and after REM sleep deprivation.

    Science.gov (United States)

    Nielsen, Tore A; Paquette, Tyna; Solomonova, Elizaveta; Lara-Carrasco, Jessica; Popova, Ani; Levrier, Katia

    2010-02-01

    To examine whether disrupted regulation of REM sleep propensity is implicated in nightmare (NM) pathophysiology. Heightened REM propensity induced by REM sleep deprivation is belied by increases in REM %, REM density and the dream-like quality of dream mentation during post-deprivation recovery sleep. Compromised regulation of REM sleep propensity may be a contributing factor in the pathophysiology of frequent NMs. A preliminary study of 14 subjects with frequent NMs (> or = 1 NM/week; 27.6+/-9.9 years) and 11 healthy control subjects (dream logs and underwent three nights of polysomnographic recording with REM sleep deprivation on night 2. Group differences were assessed for a battery of REM sleep and dream measures on nights 1 and 3. Several measures, including #skipped early-night REM periods, REM latency, REM/NREM cycle length, early/late REM density, REM rebound, late-night REM% and dream vividness, suggested that REM sleep propensity was abnormally low for the frequent NM group throughout the 3-day study. Findings raise the possibility that REM anomalies recorded from NM sufferers sleeping in the laboratory environment reflect a disruption of one or more endogenous regulators of REM sleep propensity. 2009 Elsevier B.V. All rights reserved.

  16. Sleep and Infant Learning

    Science.gov (United States)

    Tarullo, Amanda R.; Balsam, Peter D.; Fifer, William P.

    2011-01-01

    Human neonates spend the majority of their time sleeping. Despite the limited waking hours available for environmental exploration, the first few months of life are a time of rapid learning about the environment. The organization of neonate sleep differs qualitatively from adult sleep, and the unique characteristics of neonatal sleep may promote…

  17. Assessment of human sleep depth is being de-standardized by recently advised EEG electrode locations.

    Directory of Open Access Journals (Sweden)

    Bob Kemp

    Full Text Available Human sleep depth was traditionally assessed by scoring electro-encephalographic slow-wave amplitudes at the globally standardized C4-M1 electrode derivation. Since 2007, the American Association of Sleep Medicine (AASM has accepted three additional derivations for the same purpose. These might well differ in slow wave amplitudes which would bias the scorings. Some derivations might also introduce large inter-individual variability. We compared mean and variability of slow wave amplitudes between six derivations including the four AASM ones. Slow wave amplitudes in those derivations were simultaneously measured using automated analysis in 29 patients. Each amplitude was divided by the average from the six derivations, thus removing shared factors such as age, gender and sleep depth while retaining factors that differ between the derivations such as caused by local skull characteristics, electrode distance and neuronal dipole orientation. The remaining inter-individual variability differed significantly and up to a factor of two between the AASM derivations. The amplitudes differed significantly and up to 60% between the AASM derivations, causing substantial scoring bias between centres using different derivations. The resulting de-standardization most likely affects any patient group because the amplitude differences were consistent over diagnoses, genders, and age. Derivation-dependent amplitude thresholds were proposed to reduce the scoring bias. However, it would be better to settle on just one derivation, for instance Cz-Oz or Fpz-Cz because these have lowest variability while matching the traditional C4-M1 amplitudes.

  18. Sleep and Metabolism: An Overview

    Directory of Open Access Journals (Sweden)

    Sunil Sharma

    2010-01-01

    Full Text Available Sleep and its disorders are increasingly becoming important in our sleep deprived society. Sleep is intricately connected to various hormonal and metabolic processes in the body and is important in maintaining metabolic homeostasis. Research shows that sleep deprivation and sleep disorders may have profound metabolic and cardiovascular implications. Sleep deprivation, sleep disordered breathing, and circadian misalignment are believed to cause metabolic dysregulation through myriad pathways involving sympathetic overstimulation, hormonal imbalance, and subclinical inflammation. This paper reviews sleep and metabolism, and how sleep deprivation and sleep disorders may be altering human metabolism.

  19. Scale-free fluctuations in behavioral performance: delineating changes in spontaneous behavior of humans with induced sleep deficiency.

    Science.gov (United States)

    Ochab, Jeremi K; Tyburczyk, Jacek; Beldzik, Ewa; Chialvo, Dante R; Domagalik, Aleksandra; Fafrowicz, Magdalena; Gudowska-Nowak, Ewa; Marek, Tadeusz; Nowak, Maciej A; Oginska, Halszka; Szwed, Jerzy

    2014-01-01

    The timing and dynamics of many diverse behaviors of mammals, e.g., patterns of animal foraging or human communication in social networks exhibit complex self-similar properties reproducible over multiple time scales. In this paper, we analyze spontaneous locomotor activity of healthy individuals recorded in two different conditions: during a week of regular sleep and a week of chronic partial sleep deprivation. After separating activity from rest with a pre-defined activity threshold, we have detected distinct statistical features of duration times of these two states. The cumulative distributions of activity periods follow a stretched exponential shape, and remain similar for both control and sleep deprived individuals. In contrast, rest periods, which follow power-law statistics over two orders of magnitude, have significantly distinct distributions for these two groups and the difference emerges already after the first night of shortened sleep. We have found steeper distributions for sleep deprived individuals, which indicates fewer long rest periods and more turbulent behavior. This separation of power-law exponents is the main result of our investigations, and might constitute an objective measure demonstrating the severity of sleep deprivation and the effects of sleep disorders.

  20. Scale-free fluctuations in behavioral performance: delineating changes in spontaneous behavior of humans with induced sleep deficiency.

    Directory of Open Access Journals (Sweden)

    Jeremi K Ochab

    Full Text Available The timing and dynamics of many diverse behaviors of mammals, e.g., patterns of animal foraging or human communication in social networks exhibit complex self-similar properties reproducible over multiple time scales. In this paper, we analyze spontaneous locomotor activity of healthy individuals recorded in two different conditions: during a week of regular sleep and a week of chronic partial sleep deprivation. After separating activity from rest with a pre-defined activity threshold, we have detected distinct statistical features of duration times of these two states. The cumulative distributions of activity periods follow a stretched exponential shape, and remain similar for both control and sleep deprived individuals. In contrast, rest periods, which follow power-law statistics over two orders of magnitude, have significantly distinct distributions for these two groups and the difference emerges already after the first night of shortened sleep. We have found steeper distributions for sleep deprived individuals, which indicates fewer long rest periods and more turbulent behavior. This separation of power-law exponents is the main result of our investigations, and might constitute an objective measure demonstrating the severity of sleep deprivation and the effects of sleep disorders.

  1. A model of human sleep-related growth hormone secretion in dogs: effects of 3, 6, and 12 hours of forced wakefulness on plasma growth hormone, cortisol, and sleep stages.

    Science.gov (United States)

    Takahashi, Y; Ebihara, S; Nakamura, Y; Takahashi, K

    1981-07-01

    Twenty-four canine GH (cGH) and cortisol secretion patterns associated with sleep stages were studied in 10 male adult dogs. Plasma samples were obtained at 30- or 15-min intervals via an indwelling catheter. Under baseline conditions, all dogs showed irregular polyphasic sleep, and the episodic cGH secretion had no apparent relationship with sleep or the light-dark cycle. Five dogs were subjected to regular sleep-wake cycles; 3, 6, and 12 h of forced wakefulness (FW) were repeated at 3-, 6-, and 12-h intervals (recovery sleep periods), respectively. Peak cGH secretion (mean +/- SD, 6.4 ng/ml +/- 2.4) occurred soon after recovery sleep onset in 25 of 40 total recovery periods. The incidence of sleep-onset cGH peaks and cGH secretion during the first hour of recovery sleep significantly increased with the length of the preceding FW, but were not affected by the time of day. Delta wave sleep increased during this hour, suggesting a possible correlation with the sleep-onset cGH peak. During the first 3 h of recovery after 6 and 12 h of FW, cGH secretion was significantly enhanced, but cortisol was not. Considering the characteristics of human sleep-related GH secretion, we suggest that this peak cGH secretion represents a model of human GH secretion. Possibly, a close association of cGH secretion with sleep is concealed under the baseline condition and uncovered by inducing longer sleep-wake cycles in dogs. No circadian cortisol variation was detected under the baseline or the experimental conditions.

  2. Reduction of human sleep duration after bright light exposure in the morning

    NARCIS (Netherlands)

    Dijk, D.J.; Visscher, C.A.; Bloem, G.M.; Beersma, D.G.M.; Daan, S.

    1987-01-01

    In 8 subjects the spontaneous termination of sleep was determined after repetitive exposure to either bright or dim light, between 6:00 and 9:00 h, on 3 days preceding sleep assessment. Sleep duration was significantly shorter following bright light than following dim light. During sleep the time

  3. Acute sleep deprivation: the effects of the AMPAKINE compound CX717 on human cognitive performance, alertness and recovery sleep.

    Science.gov (United States)

    Boyle, Julia; Stanley, Neil; James, Lynette M; Wright, Nicola; Johnsen, Sigurd; Arbon, Emma L; Dijk, Derk-Jan

    2012-08-01

    AMPA receptor modulation is a potential novel approach to enhance cognitive performance. CX717 is a positive allosteric modulator of the AMPA receptor that has shown efficacy in rodent and primate cognition models. CX717 (100 mg, 300 mg and 1000 mg) and placebo were studied in 16 healthy male volunteers (18-45 years) in a randomized, crossover study. Cognitive function, arousal and recovery sleep (by polysomnography) were assessed during the extended wakefulness protocol. Placebo condition was associated with significant decrements in cognition, particularly at the circadian nadir (between 03:00 and 05:00). Pre-specified primary and secondary analyses (general linear mixed modelling, GLMM) at each separate time point did not reveal consistent improvements in performance or objective alertness with any dose of CX717. Exploratory repeated measures analysis, a method used to take into account the influence of individual differences, demonstrated an improvement in attention-based task performance following the 1000 mg dose. Analysis of the recovery sleep showed that CX717 1000 mg significantly reduced stage 4 and slow-wave sleep (p ≤ 0.05) with evidence of reduced electroencephalogram (EEG) slow-wave and spindle activity. The study suggests that CX717 only at the 1000 mg dose may counteract effects of sleep deprivation on attention-based tasks and that it may interfere with subsequent recovery sleep.

  4. The effect of electromagnetic fields emitted by mobile phones on human sleep.

    Science.gov (United States)

    Loughran, Sarah P; Wood, Andrew W; Barton, Julie M; Croft, Rodney J; Thompson, Bruce; Stough, Con

    2005-11-28

    Previous research has suggested that exposure to radiofrequency electromagnetic fields increases electroencephalogram spectral power in non-rapid eye movement sleep. Other sleep parameters have also been affected following exposure. We examined whether aspects of sleep architecture show sensitivity to electromagnetic fields emitted by digital mobile phone handsets. Fifty participants were exposed to electromagnetic fields for 30 min prior to sleep. Results showed a decrease in rapid eye movement sleep latency and increased electroencephalogram spectral power in the 11.5-12.25 Hz frequency range during the initial part of sleep following exposure. These results are evidence that mobile phone exposure prior to sleep may promote rapid eye movement sleep and modify the sleep electroencephalogram in the first non-rapid eye movement sleep period.

  5. Cutaneous warming promotes sleep onset

    National Research Council Canada - National Science Library

    Roy J. E. M. Raymann; Dick F. Swaab; Eus J. W. Van Someren

    2005-01-01

    Sleep occurs in close relation to changes in body temperature. Both the monophasic sleep period in humans and the polyphasic sleep periods in rodents tend to be initiated when core body temperature is declining...

  6. Entrepreneurial Propensity of Innovation Systems

    OpenAIRE

    Radosevic, S; Yoruk, E.

    2012-01-01

    This paper develops an analytical framework, namely the concept of entrepreneurial propensity of innovation systems by integrating knowledge intensive entrepreneurship (KIE) and innovation system (IS) concepts. It first uses a composite index methodology to measure knowledge intensive entrepreneurship and entrepreneurial opportunities at the national level. It then assesses the influence of the system's complementary activities on the emergence of KIE by OLS regressions and structural equatio...

  7. Differential regulation of circadian melatonin rhythm and sleep-wake cycle by bright lights and nonphotic time cues in humans.

    Science.gov (United States)

    Yamanaka, Yujiro; Hashimoto, Satoko; Masubuchi, Satoru; Natsubori, Akiyo; Nishide, Shin-Ya; Honma, Sato; Honma, Ken-Ichi

    2014-09-01

    Our previous study demonstrated that physical exercise under dim lights (sleep-wake cycle but not the circadian melatonin rhythm to an 8-h phase-advanced sleep schedule, indicating differential effects of physical exercise on the human circadian system. The present study examined the effects of bright light (>5,000 lux) on exercise-induced acceleration of reentrainment because timed bright lights are known to reset the circadian pacemaker. Fifteen male subjects spent 12 days in temporal isolation. The sleep schedule was advanced from habitual sleep times by 8 h for 4 days, which was followed by a free-run session. In the shift session, bright lights were given during the waking time. Subjects in the exercise group performed 2-h bicycle running twice a day. Subjects in the control kept quiet. As a result, the sleep-wake cycle was fully entrained by the shift schedule in both groups. Bright light may strengthen the resetting potency of the shift schedule. By contrast, the circadian melatonin rhythm was phase-advanced by 6.9 h on average in the exercise group but only by 2.0 h in the control. Thus physical exercise prevented otherwise unavoidable internal desynchronization. Polysomnographical analyses revealed that deterioration of sleep quality by shift schedule was protected by physical exercise under bright lights. These findings indicate differential regulation of sleep-wake cycle and circadian melatonin rhythm by physical exercise in humans. The melatonin rhythm is regulated primarily by bright lights, whereas the sleep-wake cycle is by nonphotic time cues, such as physical exercise and shift schedule. Copyright © 2014 the American Physiological Society.

  8. Sleep and cognition.

    Science.gov (United States)

    Deak, Maryann C; Stickgold, Robert

    2010-07-01

    Sleep is a complex physiologic state, the importance of which has long been recognized. Lack of sleep is detrimental to humans and animals. Over the past decade, an important link between sleep and cognitive processing has been established. Sleep plays an important role in consolidation of different types of memory and contributes to insightful, inferential thinking. While the mechanism by which memories are processed in sleep remains unknown, several experimental models have been proposed. This article explores the link between sleep and cognition by reviewing (1) the effects of sleep deprivation on cognition, (2) the influence of sleep on consolidation of declarative and non-declarative memory, and (3) some proposed models of how sleep facilitates memory consolidation in sleep. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website. Copyright © 2010 John Wiley & Sons, Ltd.

  9. Phase space and power spectral approaches for EEG-based automatic sleep-wake classification in humans: a comparative study using short and standard epoch lengths.

    Science.gov (United States)

    Brignol, Arnaud; Al-Ani, Tarik; Drouot, Xavier

    2013-03-01

    Sleep disorders in humans have become a public health issue in recent years. Sleep can be analysed by studying the electroencephalogram (EEG) recorded during a night's sleep. Alternating between sleep-wake stages gives information related to the sleep quality and quantity since this alternating pattern is highly affected during sleep disorders. Spectral composition of EEG signals varies according to sleep stages, alternating phases of high energy associated to low frequency (deep sleep) with periods of low energy associated to high frequency (wake and light sleep). The analysis of sleep in humans is usually made on periods (epochs) of 30-s length according to the original Rechtschaffen and Kales sleep scoring manual. In this work, we propose a new phase space-based (mainly based on Poincaré plot) algorithm for automatic classification of sleep-wake states in humans using EEG data gathered over relatively short-time periods. The effectiveness of our approach is demonstrated through a series of experiments involving EEG data from seven healthy adult female subjects and was tested on epoch lengths ranging from 3-s to 30-s. The performance of our phase space approach was compared to a 2-dimensional state space approach using the power spectral (PS) in two selected human-specific frequency bands. These powers were calculated by dividing integrated spectral amplitudes at selected human-specific frequency bands. The comparison demonstrated that the phase space approach gives better performance in the case of short as well as standard 30-s epoch lengths. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Slow-wave sleep deficiency and enhancement: implications for insomnia and its management.

    Science.gov (United States)

    Dijk, Derk-Jan

    2010-06-01

    In humans, slow-wave sleep (SWS) consists of stages 3 and 4 of non rapid eye movement (nonREM) sleep. The low-frequency, high-amplitude slow waves that dominate the electroencephalogram (EEG) during SWS can be quantified as slow-wave activity (SWA). SWS and SWA are regulated very accurately in response to variations in the duration and intensity of wakefulness and sleep. SWA declines more or less independently of circadian phase during the course of a sleep episode, indicating that it is primarily under homeostatic rather than circadian control. An age-related decline in SWS and SWA is well established. In some studies, apprehension, depression and insomnia have been associated with reductions in SWS and SWA. Experimental reductions of SWS through SWS deprivation (without altering total sleep time or REM duration) have been reported to lead to an increase in daytime sleep propensity and reductions in performance. SWS and SWA are therefore thought to contribute to the recovery processes that occur during sleep. Most currently prescribed hypnotics, such as the benzodiazepines and Z-drugs, suppress SWA. Some compounds have been shown to enhance SWS and SWA in healthy volunteers through GAT-1 inhibition, GABA-A modulation, GABA-B modulation, and 5HT2(A) antagonism. Pharmacological enhancement of SWS has also been observed in insomnia. The effects of SWS enhancement on other sleep parameters will be discussed.

  11. Human and rat gut microbiome composition is maintained following sleep restriction

    NARCIS (Netherlands)

    Zhang, Shirley L; Bai, Lei; Goel, Namni; Bailey, Aubrey; Jang, Christopher J; Bushman, Frederic D; Meerlo, Peter; Dinges, David F; Sehgal, Amita

    Insufficient sleep increasingly characterizes modern society, contributing to a host of serious medical problems. Loss of sleep is associated with metabolic diseases such as obesity and diabetes, cardiovascular disorders, and neurological and cognitive impairments. Shifts in gut microbiome

  12. Partial sleep deprivation activates the DNA damage response (DDR) and the senescence-associated secretory phenotype (SASP) in aged adult humans.

    Science.gov (United States)

    Carroll, Judith E; Cole, Steven W; Seeman, Teresa E; Breen, Elizabeth C; Witarama, Tuff; Arevalo, Jesusa M G; Ma, Jeffrey; Irwin, Michael R

    2016-01-01

    Age-related disease risk has been linked to short sleep duration and sleep disturbances; however, the specific molecular pathways linking sleep loss with diseases of aging are poorly defined. Key cellular events seen with aging, which are thought to contribute to disease, may be particularly sensitive to sleep loss. We tested whether one night of partial sleep deprivation (PSD) would increase leukocyte gene expression indicative of DNA damage responses (DDR), the senescence-associated secretory phenotype (SASP), and senescence indicator p16(INK4a) in older adult humans, who are at increased risk for cellular senescence. Community-dwelling older adults aged 61-86years (n=29; 48% male) underwent an experimental partial sleep deprivation (PSD) protocol over 4 nights, including adaptation, an uninterrupted night of sleep, partial sleep deprivation (sleep restricted 3-7AM), and a subsequent full night of sleep. Blood samples were obtained each morning to assess peripheral blood mononuclear cell (PBMC) gene expression using Illumina HT-12 arrays. Analyses of microarray results revealed that SASP (psenescence marker p16(INK4a) (CDKN2A) was increased 1day after PSD compared to baseline (psenescence. These findings causally link sleep deprivation to the molecular processes associated with biological aging. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. RSV and its propensity for causing bronchiolitis

    Science.gov (United States)

    Pickles, Raymond J; DeVincenzo, John

    2014-01-01

    Infants and young children with acute onset of wheezing and reduced respiratory airflows are often diagnosed with obstruction and inflammation of the small bronchiolar airways, i.e., bronchiolitis. The most common eitological agents causing bronchiolitis in young children are the respiratory viruses and of the commonly encountered respiratory viruses, Respiratory Syncytial Virus (RSV) has a propensity for causing bronchiolitis. Indeed, RSV bronchiolitis remains the major reason why previously healthy infants are admitted to hospital. Why RSV infection is such a predominant cause of bronchiolitis is the subject of this review. By reviewing the available histopathology of RSV bronchiolitis both in humans and relevant animal models we identify hallmark features of RSV infection of the distal airways and focus attention on the consequences of columnar cell cytopathology occurring in the bronchioles, which directly impacts the development of bronchiolar obstruction, inflammation and disease. PMID:25302625

  14. Neurocognitive consequences of sleep deprivation.

    Science.gov (United States)

    Goel, Namni; Rao, Hengyi; Durmer, Jeffrey S; Dinges, David F

    2009-09-01

    Sleep deprivation is associated with considerable social, financial, and health-related costs, in large measure because it produces impaired cognitive performance due to increasing sleep propensity and instability of waking neurobehavioral functions. Cognitive functions particularly affected by sleep loss include psychomotor and cognitive speed, vigilant and executive attention, working memory, and higher cognitive abilities. Chronic sleep-restriction experiments--which model the kind of sleep loss experienced by many individuals with sleep fragmentation and premature sleep curtailment due to disorders and lifestyle--demonstrate that cognitive deficits accumulate to severe levels over time without full awareness by the affected individual. Functional neuroimaging has revealed that frequent and progressively longer cognitive lapses, which are a hallmark of sleep deprivation, involve distributed changes in brain regions including frontal and parietal control areas, secondary sensory processing areas, and thalamic areas. There are robust differences among individuals in the degree of their cognitive vulnerability to sleep loss that may involve differences in prefrontal and parietal cortices, and that may have a basis in genes regulating sleep homeostasis and circadian rhythms. Thus, cognitive deficits believed to be a function of the severity of clinical sleep disturbance may be a product of genetic alleles associated with differential cognitive vulnerability to sleep loss. Thieme Medical Publishers.

  15. Sleep Pharmacogenetics: Personalized Sleep-Wake Therapy.

    Science.gov (United States)

    Holst, Sebastian C; Valomon, Amandine; Landolt, Hans-Peter

    2016-01-01

    Research spanning (genetically engineered) animal models, healthy volunteers, and sleep-disordered patients has identified the neurotransmitters and neuromodulators dopamine, serotonin, norepinephrine, histamine, hypocretin, melatonin, glutamate, acetylcholine, γ-amino-butyric acid, and adenosine as important players in the regulation and maintenance of sleep-wake-dependent changes in neuronal activity and the sleep-wake continuum. Dysregulation of these neurochemical systems leads to sleep-wake disorders. Most currently available pharmacological treatments are symptomatic rather than causal, and their beneficial and adverse effects are often variable and in part genetically determined. To evaluate opportunities for evidence-based personalized medicine with present and future sleep-wake therapeutics, we review here the impact of known genetic variants affecting exposure of and sensitivity to drugs targeting the neurochemistry of sleep-wake regulation and the pathophysiology of sleep-wake disturbances. Many functional polymorphisms modify drug response phenotypes relevant for sleep. To corroborate the importance of these and newly identified variants for personalized sleep-wake therapy, human sleep pharmacogenetics should be complemented with pharmacogenomic investigations, research about sleep-wake-dependent pharmacological actions, and studies in mice lacking specific genes. These strategies, together with future knowledge about epigenetic mechanisms affecting sleep-wake physiology and treatment outcomes, may lead to potent and safe novel therapies for the increasing number of sleep-disordered patients (e.g., in aged populations).

  16. A longitudinal assessment of sleep timing, circadian phase, and phase angle of entrainment across human adolescence.

    Science.gov (United States)

    Crowley, Stephanie J; Van Reen, Eliza; LeBourgeois, Monique K; Acebo, Christine; Tarokh, Leila; Seifer, Ronald; Barker, David H; Carskadon, Mary A

    2014-01-01

    The aim of this descriptive analysis was to examine sleep timing, circadian phase, and phase angle of entrainment across adolescence in a longitudinal study design. Ninety-four adolescents participated; 38 (21 boys) were 9-10 years ("younger cohort") and 56 (30 boys) were 15-16 years ("older cohort") at the baseline assessment. Participants completed a baseline and then follow-up assessments approximately every six months for 2.5 years. At each assessment, participants wore a wrist actigraph for at least one week at home to measure self-selected sleep timing before salivary dim light melatonin onset (DLMO) phase - a marker of the circadian timing system - was measured in the laboratory. Weekday and weekend sleep onset and offset and weekend-weekday differences were derived from actigraphy. Phase angles were the time durations from DLMO to weekday sleep onset and offset times. Each cohort showed later sleep onset (weekend and weekday), later weekend sleep offset, and later DLMO with age. Weekday sleep offset shifted earlier with age in the younger cohort and later in the older cohort after age 17. Weekend-weekday sleep offset differences increased with age in the younger cohort and decreased in the older cohort after age 17. DLMO to sleep offset phase angle narrowed with age in the younger cohort and became broader in the older cohort. The older cohort had a wider sleep onset phase angle compared to the younger cohort; however, an age-related phase angle increase was seen in the younger cohort only. Individual differences were seen in these developmental trajectories. This descriptive study indicated that circadian phase and self-selected sleep delayed across adolescence, though school-day sleep offset advanced until no longer in high school, whereupon offset was later. Phase angle changes are described as an interaction of developmental changes in sleep regulation interacting with psychosocial factors (e.g., bedtime autonomy).

  17. A longitudinal assessment of sleep timing, circadian phase, and phase angle of entrainment across human adolescence.

    Directory of Open Access Journals (Sweden)

    Stephanie J Crowley

    Full Text Available The aim of this descriptive analysis was to examine sleep timing, circadian phase, and phase angle of entrainment across adolescence in a longitudinal study design. Ninety-four adolescents participated; 38 (21 boys were 9-10 years ("younger cohort" and 56 (30 boys were 15-16 years ("older cohort" at the baseline assessment. Participants completed a baseline and then follow-up assessments approximately every six months for 2.5 years. At each assessment, participants wore a wrist actigraph for at least one week at home to measure self-selected sleep timing before salivary dim light melatonin onset (DLMO phase - a marker of the circadian timing system - was measured in the laboratory. Weekday and weekend sleep onset and offset and weekend-weekday differences were derived from actigraphy. Phase angles were the time durations from DLMO to weekday sleep onset and offset times. Each cohort showed later sleep onset (weekend and weekday, later weekend sleep offset, and later DLMO with age. Weekday sleep offset shifted earlier with age in the younger cohort and later in the older cohort after age 17. Weekend-weekday sleep offset differences increased with age in the younger cohort and decreased in the older cohort after age 17. DLMO to sleep offset phase angle narrowed with age in the younger cohort and became broader in the older cohort. The older cohort had a wider sleep onset phase angle compared to the younger cohort; however, an age-related phase angle increase was seen in the younger cohort only. Individual differences were seen in these developmental trajectories. This descriptive study indicated that circadian phase and self-selected sleep delayed across adolescence, though school-day sleep offset advanced until no longer in high school, whereupon offset was later. Phase angle changes are described as an interaction of developmental changes in sleep regulation interacting with psychosocial factors (e.g., bedtime autonomy.

  18. A Longitudinal Assessment of Sleep Timing, Circadian Phase, and Phase Angle of Entrainment across Human Adolescence

    Science.gov (United States)

    Crowley, Stephanie J.; Van Reen, Eliza; LeBourgeois, Monique K.; Acebo, Christine; Tarokh, Leila; Seifer, Ronald; Barker, David H.; Carskadon, Mary A.

    2014-01-01

    The aim of this descriptive analysis was to examine sleep timing, circadian phase, and phase angle of entrainment across adolescence in a longitudinal study design. Ninety-four adolescents participated; 38 (21 boys) were 9–10 years (“younger cohort”) and 56 (30 boys) were 15–16 years (“older cohort”) at the baseline assessment. Participants completed a baseline and then follow-up assessments approximately every six months for 2.5 years. At each assessment, participants wore a wrist actigraph for at least one week at home to measure self-selected sleep timing before salivary dim light melatonin onset (DLMO) phase – a marker of the circadian timing system – was measured in the laboratory. Weekday and weekend sleep onset and offset and weekend-weekday differences were derived from actigraphy. Phase angles were the time durations from DLMO to weekday sleep onset and offset times. Each cohort showed later sleep onset (weekend and weekday), later weekend sleep offset, and later DLMO with age. Weekday sleep offset shifted earlier with age in the younger cohort and later in the older cohort after age 17. Weekend-weekday sleep offset differences increased with age in the younger cohort and decreased in the older cohort after age 17. DLMO to sleep offset phase angle narrowed with age in the younger cohort and became broader in the older cohort. The older cohort had a wider sleep onset phase angle compared to the younger cohort; however, an age-related phase angle increase was seen in the younger cohort only. Individual differences were seen in these developmental trajectories. This descriptive study indicated that circadian phase and self-selected sleep delayed across adolescence, though school-day sleep offset advanced until no longer in high school, whereupon offset was later. Phase angle changes are described as an interaction of developmental changes in sleep regulation interacting with psychosocial factors (e.g., bedtime autonomy). PMID:25380248

  19. Regional cerebral glucose metabolic rate in human sleep assessed by positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Buchsbaum, M.S.; Wu, J.; Hazlett, E.; Sicotte, N.; Bunney, W.E. Jr. (Univ. of California, Irvine (USA)); Gillin, J.C. (Univ. of California, San Diego (USA))

    1989-01-01

    The cerebral metabolic rate of glucose was measured during nighttime sleep in 36 normal volunteers using positron emission tomography and fluorine-18-labeled 2-deoxyglucose (FDG). In comparison to waking controls, subjects given FDG during non-rapid eye movement (NREM) sleep showed about a 23% reduction in metabolic rate across the entire brain. This decrease was greater for the frontal than temporal or occipital lobes, and greater for basal ganglia and thalamus than cortex. Subjects in rapid eye movement (REM) sleep tended to have higher cortical metabolic rates than walking subjects. The cingulate gyrus was the only cortical structure to show a significant increase in glucose metabolic rate in REM sleep in comparison to waking. The basal ganglia were relatively more active on the right in REM sleep and symmetrical in NREM sleep.

  20. REM Sleep, Prefrontal Theta, and the Consolidation of Human Emotional Memory

    OpenAIRE

    Nishida, Masaki; Pearsall, Jori; Walker, Matthew P; Buckner, Randy Lee

    2008-01-01

    Both emotion and sleep are independently known to modulate declarative memory. Memory can be facilitated by emotion, leading to enhanced consolidation across increasing time delays. Sleep also facilitates offline memory processing, resulting in superior recall the next day. Here we explore whether rapid eye movement (REM) sleep, and aspects of its unique neurophysiology, underlie these convergent influences on memory. Using a nap paradigm, we measured the consolidation of neutral and negative...

  1. Time course of sleep inertia dissipation in human performance and alertness

    Science.gov (United States)

    Jewett, M. E.; Wyatt, J. K.; Ritz-De Cecco, A.; Khalsa, S. B.; Dijk, D. J.; Czeisler, C. A.

    1999-01-01

    Alertness and performance on a wide variety of tasks are impaired immediately upon waking from sleep due to sleep inertia, which has been found to dissipate in an asymptotic manner following waketime. It has been suggested that behavioural or environmental factors, as well as sleep stage at awakening, may affect the severity of sleep inertia. In order to determine the time course of sleep inertia dissipation under normal entrained conditions, subjective alertness and cognitive throughput were measured during the first 4 h after habitual waketime from a full 8-h sleep episode on 3 consecutive days. We investigated whether this time course was affected by either sleep stage at awakening or behavioural/environmental factors. Sleep inertia dissipated in an asymptotic manner and took 2-4 h to near the asymptote. Saturating exponential functions fitted the sleep inertia data well, with time constants of 0.67 h for subjective alertness and 1.17 h for cognitive performance. Most awakenings occurred out of stage rapid eye movement (REM), 2 or 1 sleep, and no effect of sleep stage at awakening on either the severity of sleep inertia or the time course of its dissipation could be detected. Subjective alertness and cognitive throughput were significantly impaired upon awakening regardless of whether subjects got out of bed, ate breakfast, showered and were exposed to ordinary indoor room light (approximately 150 lux) or whether subjects participated in a constant routine (CR) protocol in which they remained in bed, ate small hourly snacks and were exposed to very dim light (10-15 lux). These findings allow for the refinement of models of alertness and performance, and have important implications for the scheduling of work immediately upon awakening in many occupational settings.

  2. Exposure to dim artificial light at night increases REM sleep and awakenings in humans.

    Science.gov (United States)

    Cho, Chul-Hyun; Lee, Heon-Jeong; Yoon, Ho-Kyoung; Kang, Seung-Gul; Bok, Ki-Nam; Jung, Ki-Young; Kim, Leen; Lee, Eun-Il

    2016-01-01

    Exposure to artificial light at night (ALAN) has become increasing common, especially in developed countries. We investigated the effect of dALAN exposure during sleep in healthy young male subjects. A total of 30 healthy young male volunteers from 21 to 29 years old were recruited for the study. They were randomly divided into two groups depending on light intensity (Group A: 5 lux and Group B: 10 lux). After a quality control process, 23 healthy subjects were included in the study (Group A: 11 subjects, Group B: 12 subjects). Subjects underwent an NPSG session with no light (Night 1) followed by an NPSG session randomly assigned to two different dim light conditions (5 or 10 lux, dom λ: 501.4 nm) for a whole night (Night 2). We found significant sleep structural differences between Nights 1 and 2, but no difference between Groups A and B. Exposure to dALAN during sleep was significantly associated with increased wake time after sleep onset (WASO; F = 7.273, p = 0.014), increased Stage N1 (F = 4.524, p = 0.045), decreased Stage N2 (F = 9.49, p = 0.006), increased Stage R (F = 6.698, p = 0.017) and non-significantly decreased REM density (F = 4.102, p = 0.056). We found that dALAN during sleep affects sleep structure. Exposure to dALAN during sleep increases the frequency of arousals, amount of shallow sleep and amount of REM sleep. This suggests adverse effects of dALAN during sleep on sleep quality and suggests the need to avoid exposure to dALAN during sleep.

  3. Effects of aging on slow-wave sleep dynamics and human spatial navigational memory consolidation.

    Science.gov (United States)

    Varga, Andrew W; Ducca, Emma L; Kishi, Akifumi; Fischer, Esther; Parekh, Ankit; Koushyk, Viachaslau; Yau, Po Lai; Gumb, Tyler; Leibert, David P; Wohlleber, Margaret E; Burschtin, Omar E; Convit, Antonio; Rapoport, David M; Osorio, Ricardo S; Ayappa, Indu

    2016-06-01

    The consolidation of spatial navigational memory during sleep is supported by electrophysiological and behavioral evidence. The features of sleep that mediate this ability may change with aging, as percentage of slow-wave sleep is canonically thought to decrease with age, and slow waves are thought to help orchestrate hippocampal-neocortical dialog that supports systems level consolidation. In this study, groups of younger and older subjects performed timed trials before and after polysomnographically recorded sleep on a 3D spatial maze navigational task. Although younger subjects performed better than older subjects at baseline, both groups showed similar improvement across presleep trials. However, younger subjects experienced significant improvement in maze performance during sleep that was not observed in older subjects, without differences in morning psychomotor vigilance between groups. Older subjects had sleep quality marked by decreased amount of slow-wave sleep and increased fragmentation of slow-wave sleep, resulting in decreased slow-wave activity. Across all subjects, frontal slow-wave activity was positively correlated with both overnight change in maze performance and medial prefrontal cortical volume, illuminating a potential neuroanatomical substrate for slow-wave activity changes with aging and underscoring the importance of slow-wave activity in sleep-dependent spatial navigational memory consolidation. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Sleep Apnea

    Science.gov (United States)

    ... repeated awakenings associated with sleep apnea make normal, restorative sleep impossible. People with sleep apnea often experience ... et al. Sleep breathing disorders. In: Principles and Practice of Sleep Medicine. 5th ed. St. Louis, Mo.: ...

  5. Sleeping beauty system to redirect T-cell specificity for human applications.

    Science.gov (United States)

    Maiti, Sourindra N; Huls, Helen; Singh, Harjeet; Dawson, Margaret; Figliola, Matthew; Olivares, Simon; Rao, Pullavathi; Zhao, Yi Jue; Multani, Asha; Yang, Ge; Zhang, Ling; Crossland, Denise; Ang, Sonny; Torikai, Hiroki; Rabinovich, Brian; Lee, Dean A; Kebriaei, Partow; Hackett, Perry; Champlin, Richard E; Cooper, Laurence J N

    2013-02-01

    The Sleeping Beauty (SB) transposon/transposase DNA plasmid system is used to genetically modify cells for long-term transgene expression. We adapted the SB system for human application and generated T cells expressing a chimeric antigen receptor (CAR) specific for CD19. Electrotransfer of CD19-specific SB DNA plasmids in peripheral blood mononuclear cells and propagation on CD19 artificial antigen presenting cells was used to numerically expand CD3 T cells expressing CAR. By day 28 of coculture, >90% of expanded CD3 T cells expressed CAR. CAR T cells specifically killed CD19 target cells and consisted of subsets expressing biomarkers consistent with central memory, effector memory, and effector phenotypes. CAR T cells contracted numerically in the absence of the CD19 antigen, did not express SB11 transposase, and maintained a polyclonal TCR Vα and TCR Vβ repertoire. Quantitative fluorescence in situ hybridization revealed that CAR T cells preserved the telomere length. Quantitative polymerase chain reaction and fluorescence in situ hybridization showed CAR transposon integrated on average once per T-cell genome. CAR T cells in peripheral blood can be detected by quantitative polymerase chain reaction at a sensitivity of 0.01%. These findings lay the groundwork as the basis of our first-in-human clinical trials of the nonviral SB system for the investigational treatment of CD19 B-cell malignancies (currently under 3 INDs: 14193, 14577, and 14739).

  6. Effects of mobile phone emissions on human brain activity and sleep variables.

    Science.gov (United States)

    Hamblin, D L; Wood, A W

    2002-08-01

    To compare the findings of the main studies that have examined the effects of GSM mobile phone radiofrequency emissions on human brain activity and sleep variables. Fourteen published studies reporting on human brain electrical activity measurements during and/or after such radiofrequency emissions were identified and compared. Although, in general, outcomes have been inconsistent and comparison between individual studies is difficult, enhanced electroencephalogram alpha-band power has been noted in several of the studies, a phenomenon also observed in some animal studies. Performance decrements observed in some recent extremely low frequency studies are consistent with enhanced alpha-band power, highlighting the possible role of extremely low frequency fields associated with battery current in mobile phone handsets. However, more complex cognitive tasks appear to show improved performance in relation to mobile phone exposure. Significant cognitive effects have been reported using both modulated and unmodulated radiofrequency carriers. The possibility of putative effects being due to extremely low frequency demodulation is therefore unlikely. There are no obvious associations between the site of exposure and regions of the brain from which effects are reported or implied. Lastly, radiofrequency effects have been reported to occur both during exposure and up to 1 h or so after cessation of exposure.

  7. Sleep restriction alters plasma endocannabinoids concentrations before but not after exercise in humans.

    Science.gov (United States)

    Cedernaes, Jonathan; Fanelli, Flaminia; Fazzini, Alessia; Pagotto, Uberto; Broman, Jan-Erik; Vogel, Heike; Dickson, Suzanne L; Schiöth, Helgi B; Benedict, Christian

    2016-12-01

    Following binding to cannabinoid receptors, endocannabinoids regulate a variety of central nervous system processes including appetite and mood. Recent evidence suggests that the systemic release of these lipid metabolites can be altered by acute exercise and that their levels also vary across the 24-h sleep-wake cycle. The present study utilized a within-subject design (involving 16 normal-weight men) to determine whether daytime circulating endocannabinoid concentrations differ following three nights of partial sleep deprivation (4.25-h sleep opportunity, 2:45-7a.m. each night) vs. normal sleep (8.5-h sleep opportunity, 10:30p.m.-7a.m. each night), before and after an acute bout of ergometer cycling in the morning. In addition, subjective hunger and stress were measured. Pre-exercise plasma concentrations of 2-arachidonoylglycerol (2AG) were 80% higher 1.5h after awakening (vs. normal sleep, psleep-deprived. This coincided with increased hunger ratings (+25% vs. normal sleep, pSleep duration did not however modulate this exercise-induced rise. Finally, subjective stress was generally lower on the day after three nights of short sleep vs. normal sleep, especially after exercise (psleep loss, such as increased hunger and transiently improved psychological state, may partially result from activation of this signaling pathway. In contrast, more pronounced exercise-induced elevations of endocannabinoids appear to be less affected by short sleep duration. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  8. Brown Norway and Zucker Lean rats demonstrate circadian variation in ventilation and sleep apnea.

    Science.gov (United States)

    Fink, Anne M; Topchiy, Irina; Ragozzino, Michael; Amodeo, Dionisio A; Waxman, Jonathan A; Radulovacki, Miodrag G; Carley, David W

    2014-04-01

    Circadian rhythms influence many biological systems, but there is limited information about circadian and diurnal variation in sleep related breathing disorder. We examined circadian and diurnal patterns in sleep apnea and ventilatory patterns in two rat strains, one with high sleep apnea propensity (Brown Norway [BN]) and the other with low sleep apnea propensity (Zucker Lean [ZL]). Chronically instrumented rats were randomized to breathe room air (control) or 100% oxygen (hyperoxia), and we performed 20-h polysomnography beginning at Zeitgeber time 4 (ZT 4; ZT 0 = lights on, ZT12 = lights off). We examined the effect of strain and inspired gas (twoway analysis of variance) and analyzed circadian and diurnal variability. Strain and inspired gas-dependent differences in apnea index (AI; apneas/h) were particularly prominent during the light phase. AI in BN rats (control, 16.9 ± 0.9; hyperoxia, 34.0 ± 5.8) was greater than in ZL rats (control, 8.5 ± 1.0; hyperoxia, 15.4 ± 1.1, [strain effect, P < 0.001; gas effect, P = 0.001]). Hyperoxia reduced respiratory frequency in both strains, and all respiratory pattern variables demonstrated circadian variability. BN rats exposed to hyperoxia demonstrated the largest circadian fluctuation in AI (amplitude = 17.9 ± 3.7 apneas/h [strain effect, P = 0.01; gas effect, P < 0.001; interaction, P = 0.02]; acrophase = 13.9 ± 0.7 h; r (2) = 0.8 ± 1.4). Inherited, environmental, and circadian factors all are important elements of underlying sleep related breathing disorder. Our method to examine sleep related breathing disorder phenotypes in rats may have implications for understanding vulnerability for sleep related breathing disorder in humans.

  9. Partial Sleep Deprivation Activates the DNA Damage Response (DDR) and the Senescence-Associated Secretory Phenotype (SASP) in Aged Adult Humans

    Science.gov (United States)

    Carroll, Judith E.; Cole, Steven W.; Seeman, Teresa E.; Breen, Elizabeth C.; Witarama, Tuff; Arevalo, Jesusa M.G.; Ma, Jeffrey; Irwin, Michael R.

    2015-01-01

    Age-related disease risk has been linked to short sleep duration and sleep disturbances; however, the specific molecular pathways linking sleep loss with diseases of aging are poorly defined. Key cellular events seen with aging, which are thought to contribute to disease, may be particularly sensitive to sleep loss. We tested whether one night of partial sleep deprivation (PSD) would increase leukocyte gene expression indicative of DNA damage responses (DDR), the senescence-associated secretory phenotype (SASP), and senescence indicator p16INK4a in older adult humans, who are at increased risk for cellular senescence. Community-dwelling older adults aged 61-86 years (n=29; 48% male) underwent an experimental partial sleep deprivation (PSD) protocol over 4 nights, including adaptation, an uninterrupted night of sleep, partial sleep deprivation (sleep restricted 3 AM to 7 AM), and a subsequent full night of sleep. Blood samples were obtained each morning to assess peripheral blood mononuclear cell (PBMC) gene expression using Illumina HT-12 arrays. Analyses of microarray results revealed that SASP (p < .05) and DDR (p = .08) gene expression were elevated from baseline to PSD nights. Gene expression changes were also observed from baseline to PSD in NFKB2, NBS1 and CHK2 (all p's < .05). The senescence marker p16INK4a (CDKN2A) was increased one day after PSD compared to baseline (p < .01), however confirmatory RT-PCR did not replicate this finding. One night of partial sleep deprivation activates PBMC gene expression patterns consistent with biological aging in this older adult sample. PSD enhanced the SASP and increased the accumulation of damage that initiates cell cycle arrest and promotes cellular senescence. These findings causally link sleep deprivation to the molecular processes associated with biological aging. PMID:26336034

  10. An automated and reliable method for breath detection during variable mask pressures in awake and sleeping humans.

    Science.gov (United States)

    Nguyen, Chinh D; Amatoury, Jason; Carberry, Jayne C; Eckert, Danny J

    2017-01-01

    Accurate breath detection is crucial in sleep and respiratory physiology research and in several clinical settings. However, this process is technically challenging due to measurement and physiological artifacts and other factors such as variable leaks in the breathing circuit. Recently developed techniques to quantify the multiple causes of obstructive sleep apnea, require intermittent changes in airway pressure applied to a breathing mask. This presents an additional unique challenge for breath detection. Traditional algorithms often require drift correction. However, this is an empirical operation potentially prone to human error. This paper presents a new algorithm for breath detection during variable mask pressures in awake and sleeping humans based on physiological landmarks detected in the airflow or epiglottic pressure signal (Pepi). The algorithms were validated using simulated data from a mathematical model and against the standard visual detection approach in 4 healthy individuals and 6 patients with sleep apnea during variable mask pressure conditions. Using the flow signal, the algorithm correctly identified 97.6% of breaths with a mean difference±SD in the onsets of respiratory phase compared to expert visual detection of 23±89ms for inspiration and 6±56ms for expiration during wakefulness and 10±74ms for inspiration and 3±28 ms for expiration with variable mask pressures during sleep. Using the Pepi signal, the algorithm correctly identified 89% of the breaths with accuracy of 31±156ms for inspiration and 9±147ms for expiration compared to expert visual detection during variable mask pressures asleep. The algorithm had excellent performance in response to baseline drifts and noise during variable mask pressure conditions. This new algorithm can be used for accurate breath detection including during variable mask pressure conditions which represents a major advance over existing time-consuming manual approaches.

  11. Circadian and Homeostatic Control of Rapid Eye Movement (REM) Sleep: Promotion of REM Tendency by the Suprachiasmatic Nucleus

    National Research Council Canada - National Science Library

    Wurts, Sarah W; Edgar, Dale M

    2000-01-01

    ...) and a homeostatic process that induces compensatory REM sleep in response to REM sleep loss. Whether the circadian variation in REM sleep propensity is caused by active promotion, inhibition, or passive gating of REM sleep homeostasis by the SCN is unknown...

  12. Memory stabilization with targeted reactivation during human slow-wave sleep

    NARCIS (Netherlands)

    Dongen, E.V. van; Takashima, A.; Barth, M.; Zapp, J.; Schad, L.R.; Paller, K.A.; Fernandez, G.S.E.

    2012-01-01

    It is believed that neural representations of recent experiences become reactivated during sleep, and that this process serves to stabilize associated memories in long-term memory. Here, we initiated this reactivation process for specific memories during slow-wave sleep. Participants studied 50

  13. Bright morning light advances the human circadian system without affecting NREM sleep homeostasis

    NARCIS (Netherlands)

    Dijk, Derk Jan; Beersma, Domien G.M.; Daan, Serge; Lewy, Alfred J.

    Eight male subjects were exposed to either bright light or dim light between 0600 and 0900 h for 3 consecutive days each. Relative to the dim light condition, the bright light treatment advanced the evening rise in plasma melatonin and the time of sleep termination (sleep onset was held constant)

  14. Some remarks on the effects of drugs, lack of sleep and loud noise on human performance.

    NARCIS (Netherlands)

    Sanders, A.F. & A.A. Bunt.

    1971-01-01

    Some literature is reviewed on the effect of some drugs, (amphetamine, hypnotics, alcohol), loud noise and sleep loss in test of time estimation, decision making, long term performance and short term memory. Results are most clear with respect to amphetamine, hypnotics and lack of sleep, in that

  15. The effects of sleep-deprivation and incentives on human-performance

    NARCIS (Netherlands)

    Steyvers, Frank J.J.M.; Gaillard, Anthony W.K.

    This study explores whether KR (knowledge of results) and reward compensate for the negative joint effects of sleep deprivation and signal degradation in a choice-reaction task. The negative effect of signal degradation on performance was aggravated by sleep loss and time-on-task, whereas KR

  16. The effect of narrowband 500 nm light on daytime sleep in humans.

    Science.gov (United States)

    Harrison, Elizabeth M; Gorman, Michael R; Mednick, Sara C

    2011-05-03

    Naps frequently take place during the daytime under some ambient light. People are commonly advised to wear eyeshades, or use black-out curtains while sleeping, as light is thought to inhibit sleep. Little is known, however, about how light during daytime sleep may affect the quality or architecture of that sleep. The present within-subjects design administered green narrowband light via light masks to 17 young adults (23.2 ± 4.7 years) during four 90-minute afternoon naps. Subjects were exposed to each of four light conditions that approximate the intensity of 1) physiological darkness (~0 lx), 2) moonlight (~1 lx), 3) typical indoor lighting (~80 lx) and 4) indirect outdoor light (~6400 lx). All subjects were able to sleep in all lighting conditions, with no differences in sleep quality or architecture. Power analysis revealed sufficient power to detect meaningful differences. Sleep inertia measured upon waking showed a general effect of the nap, independent of condition. Although light has various alerting effects at night, 500 nm LED light presented via light mask does not appear to inhibit daytime sleep. The finding that this light had no effect on the ability of individuals to fall asleep or stay asleep during an afternoon nap may inform decisions regarding the use of the nap as a facilitator of schedule adjustment, and challenges the assumption of light as a barrier to napping. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Acupuncture Improves Sleep Conditions of Minipigs Representing Diurnal Animals through an Anatomically Similar Point to the Acupoint (GV20) Effective for Humans

    OpenAIRE

    Takeishi, Ka-ichiro; Horiuchi, Masahisa; Kawaguchi, Hiroaki; Deguchi, Yoshiki; Izumi, Hiroyuki; Arimura, Emi; Kuchiiwa, Satoshi; Tanimoto, Akihide; Takeuchi, Toru

    2012-01-01

    Acupuncture, an alternative medicine, has been widely applied for people with sleep disturbances; therefore, the effects should be evaluated objectively. Micro-minipigs (MMPigs), the smallest miniature pigs for animal experiments, were used. Acupuncture was performed at two different points: Dafengmen is located on the head and is an anatomically similar point to human-Baihui (GV20), an effective acupoint for sleep disturbances in humans; pig-Baihui is on the back. The procedure was performed...

  18. Modulation of the ultradian human nasal cycle by sleep stage and body position.

    Science.gov (United States)

    Frye, Richard E; Rosin, Deborah F; Morrison, Adrian R; Leon-Sarmiento, Fidias E; Doty, Richard L

    2017-01-01

    The nasal cycle, which is present in a significant number of people, is an ultradian side-to-side rhythm of nasal engorgement associated with cyclic autonomic activity. We studied the nasal cycle during REM/non-REM sleep stages and examined the potentially confounding influence of body position on lateralized nasal airflow. Left- and right-side nasal airflow was measured in six subjects during an eight-hour sleep period using nasal thermistors. Polysomnography was performed. Simultaneously, body positions were monitored using a video camera in conjunction with infrared lighting. Significantly greater airflow occurred through the right nasal chamber (relative to the left) during periods of REM sleep than during periods of non-REM sleep (psleep stage (p sleep stage are related. Some types of asymmetrical somatosensory stimulation can alter this relationship.

  19. A Study of Program Manager Effectiveness and Risk Taking Propensity

    Science.gov (United States)

    1988-09-01

    search for organizational effectiveness: a. Scientific Management - Taylor (1911). b. Principles of Management - Fayol (1916/1925). c. Human Relations... leadership . Management outcomes refer to the accomplishments of the organization or project team. This methodology is similiar to the model developed...C) W(IcFR Fl mp,’ II ~OF 4 A STUDY OF PROGRAM MANAGER EFFECTIVENESS AND RISK TAKING PROPENSITY THESIS Timothy P. McIntyre Captain, USAF AFIT/GSM/LSY

  20. Neuroscience-driven discovery and development of sleep therapeutics

    NARCIS (Netherlands)

    Dresler, M.; Spoormaker, V.I.; Beitinger, P.; Czisch, M.; Kimura, M.; Steiger, A.; Holsboer, F.

    2014-01-01

    Until recently, neuroscience has given sleep research and discovery of better treatments of sleep disturbances little attention, despite the fact that disturbed sleep has overwhelming impact on human health. Sleep is a complex phenomenon in which specific psychological, electrophysiological,

  1. Neurobiological Consequences of Sleep Deprivation

    Science.gov (United States)

    Alkadhi, Karim; Zagaar, Munder; Alhaider, Ibrahim; Salim, Samina; Aleisa, Abdulaziz

    2013-01-01

    Although the physiological function of sleep is not completely understood, it is well documented that it contributes significantly to the process of learning and memory. Ample evidence suggests that adequate sleep is essential for fostering connections among neuronal networks for memory consolidation in the hippocampus. Sleep deprivation studies are extremely valuable in understanding why we sleep and what are the consequences of sleep loss. Experimental sleep deprivation in animals allows us to gain insight into the mechanism of sleep at levels not possible to study in human subjects. Many useful approaches have been utilized to evaluate the effect of sleep loss on cognitive function, each with relative advantages and disadvantages. In this review we discuss sleep and the detrimental effects of sleep deprivation mostly in experimental animals. The negative effects of sleep deprivation on various aspects of brain function including learning and memory, synaptic plasticity and the state of cognition-related signaling molecules are discussed. PMID:24179461

  2. Neurobiological consequences of sleep deprivation.

    Science.gov (United States)

    Alkadhi, Karim; Zagaar, Munder; Alhaider, Ibrahim; Salim, Samina; Aleisa, Abdulaziz

    2013-05-01

    Although the physiological function of sleep is not completely understood, it is well documented that it contributes significantly to the process of learning and memory. Ample evidence suggests that adequate sleep is essential for fostering connections among neuronal networks for memory consolidation in the hippocampus. Sleep deprivation studies are extremely valuable in understanding why we sleep and what are the consequences of sleep loss. Experimental sleep deprivation in animals allows us to gain insight into the mechanism of sleep at levels not possible to study in human subjects. Many useful approaches have been utilized to evaluate the effect of sleep loss on cognitive function, each with relative advantages and disadvantages. In this review we discuss sleep and the detrimental effects of sleep deprivation mostly in experimental animals. The negative effects of sleep deprivation on various aspects of brain function including learning and memory, synaptic plasticity and the state of cognition-related signaling molecules are discussed.

  3. The effects of theta-burst stimulation on sleep and vigilance in humans

    Science.gov (United States)

    Mensen, Armand; Gorban, Corina; Niklaus, Marcel; Kuske, Eva; Khatami, Ramin

    2014-01-01

    Repetitive transcranial magnetic stimulation (TMS) has become a popular tool to modulate neuronal networks and associated brain functions in both clinical and basic research. Yet few studies have examined the potential effects of cortical stimulation on general levels of vigilance. In this exploratory study, we used theta-burst protocols, both continuous (cTBS) and intermittent (iTBS) patterns, to examine whether inhibition or excitation of the left dorso-lateral prefrontal cortex (dlPFC) was able to induce reliable and acute changes to vigilance measures, compared to the left dorso-lateral associative visual cortex (dlAVC) as a control site in line with previous work. Partially sleep restricted participants underwent four separate sessions in a single day, in a between subjects design for TBS stimulation type and within subjects for locaton, each consisting of maintenance of wakefulness test (MWT), a sleep latency test, and a psychomotor vigilance task (PVT). TBS significantly affected measures of sleep consolidation, namely latency to sleep stage 2 and sleep efficiency, but had no effects on sleep drive or psychomotor vigilance levels for either TBS type or location. Contrary to our initial hypothesis of the dlAVC as a control site, stimulation to this region resulted in the largest differential effects between stimulation types. Moreover, the effect of TBS was found to be consistent throughout the day. These data may provide the basis for further investigation into therapeutic applications of TBS in sleep disorders. PMID:24971057

  4. Quality of sleep and quality of life in adolescents infected with human immunodeficiency virus

    Directory of Open Access Journals (Sweden)

    Carina Caires Gazini

    2012-06-01

    Full Text Available OBJECTIVES: To assess sleep characteristics of adolescents infected by HIV, and to ascertain whether psychosocial aspects are associated to the quality of sleep. METHODS: A cross-sectional study assessing 102 HIV-infected adolescents of both genders, aged between 10 and 20 years-old and 120 Controls. Data collection was performed by applying the Sleep Disturbance Scale for Children, the Epworth Sleepiness Scale, and the Pediatric Quality of Life Inventory. RESULTS: A sleep disturbance prevalence of 77.4% was found in patients, and a 75% prevalence in controls, and there was correlation between quality of sleep and of life. HIV-infected adolescents scored higher for sleep breathing disorders and had higher prevalence of excessive daytime sleepiness. CONCLUSIONS: HIV-infected adolescents had similar quality of sleep compared to healthy adolescents. This may be explained by the steady improvements in daily living as a result of successful anti-retroviral therapy, and by the vulnerability that affects Brazilian adolescents living in major urban centers.

  5. Unraveling the Neurobiology of Sleep and Sleep Disorders Using Drosophila.

    Science.gov (United States)

    Chakravarti, L; Moscato, E H; Kayser, M S

    2017-01-01

    Sleep disorders in humans are increasingly appreciated to be not only widespread but also detrimental to multiple facets of physical and mental health. Recent work has begun to shed light on the mechanistic basis of sleep disorders like insomnia, restless legs syndrome, narcolepsy, and a host of others, but a more detailed genetic and molecular understanding of how sleep goes awry is lacking. Over the past 15 years, studies in Drosophila have yielded new insights into basic questions regarding sleep function and regulation. More recently, powerful genetic approaches in the fly have been applied toward studying primary human sleep disorders and other disease states associated with dysregulated sleep. In this review, we discuss the contribution of Drosophila to the landscape of sleep biology, examining not only fundamental advances in sleep neurobiology but also how flies have begun to inform pathological sleep states in humans. © 2017 Elsevier Inc. All rights reserved.

  6. The effect of exogenous cortisol during sleep on the behavioral and neural correlates of emotional memory consolidation in humans.

    Science.gov (United States)

    van Marle, Hein J F; Hermans, Erno J; Qin, Shaozheng; Overeem, Sebastiaan; Fernández, Guillén

    2013-09-01

    A host of animal work demonstrates that the retention benefit for emotionally aversive over neutral memories is regulated by glucocorticoid action during memory consolidation. Particularly, glucocorticoids may affect systems-level processes that promote the gradual reorganization of emotional memory traces. These effects remain largely uninvestigated in humans. Therefore, in this functional magnetic resonance imaging study we administered hydrocortisone during a polysomnographically monitored night of sleep directly after healthy volunteers studied negative and neutral pictures in a double-blind, placebo-controlled, between-subjects design. The following evening memory consolidation was probed during a recognition memory test in the MR scanner by assessing the difference in brain activity associated with memory for the consolidated items studied before sleep and new, unconsolidated items studied shortly before test (remote vs. recent memory paradigm). Hydrocortisone administration resulted in elevated cortisol levels throughout the experimental night with no group difference at recent encoding or test. Behaviorally, we showed that cortisol enhanced the difference between emotional and neutral consolidated memory, effectively prioritizing emotional memory consolidation. On a neural level, we found that cortisol reduced amygdala reactivity related to the retrieval of these same consolidated, negative items. These findings show that cortisol administration during first post-encoding sleep had a twofold effect on the first 24h of emotional memory consolidation. While cortisol prioritized recognition memory for emotional items, it reduced reactivation of the neural circuitry underlying emotional responsiveness during retrieval. These findings fit recent theories on emotional depotentiation following consolidation during sleep, although future research should establish the sleep-dependence of this effect. Moreover, our data may shed light on mechanisms underlying

  7. Bright morning light advances the human circadian system without affecting NREM sleep homeostasis

    OpenAIRE

    Dijk, Derk Jan; Beersma, Domien G.M.; Daan, Serge; Lewy, Alfred J.

    1989-01-01

    Eight male subjects were exposed to either bright light or dim light between 0600 and 0900 h for 3 consecutive days each. Relative to the dim light condition, the bright light treatment advanced the evening rise in plasma melatonin and the time of sleep termination (sleep onset was held constant) for on average ~1 h. The magnitude of the advance of the plasma melatonin rise was dependent on its phase in dim light. The reduction in sleep duration was at the expense of rapid-eye-movement (REM) ...

  8. The Neuroprotective Aspects of Sleep

    OpenAIRE

    Eugene, Andy R.; Masiak, Jolanta

    2015-01-01

    Sleep is an important component of human life, yet many people do not understand the relationship between the brain and the process of sleeping. Sleep has been proven to improve memory recall, regulate metabolism, and reduce mental fatigue. A minimum of 7 hours of daily sleep seems to be necessary for proper cognitive and behavioral function. The emotional and mental handicaps associated with chronic sleep loss as well as the highly hazardous situations which can be contributed to the lack of...

  9. [Selective stimulations and lesions of the rat brain nuclei as the models for research of the human sleep pathology mechanisms].

    Science.gov (United States)

    Šaponjić, Jasna

    2011-01-01

    Many complex behavioral phenomena such as sleep can not be explained without multidisciplinary experimental approach, and complementay approaches in the animal models "in vivo" and human studies. Electrophysiological, pharmacological, anatomical and immunohistochemical techniques, and particularly stereotaxically guided local nanovolume microinjection technique, enable us to selectively stimulate and lesion the brain nuclei or their specific neuronal subpopulation, and to reslove the mechanisms of certain brain structure regulatory role, and its afferent-efferent connectivity within the brain. Local stereotaxically guided nanovolume microinjection technique enable us to investigate in animals the brain nulcei functional topography with a resolution of sleep neuronal substrates is based on animal studies primarly in cat and rat. Selective pharmacological stimulation of the pedunculopontine tegmentum (PPT) in freely moving rat, using glutamate microinjection, proved that excitation of its cholinergic part is necessary for induction of wakefulness or REM (Datta S, 2001). Local nanovolume glutamate microinjection into PPT of anesthetized rats (Saponjić et al, 2003a) additionally evidenced P-wave and respiratory regulating neuronal subpopulation within the cholinergic compartment of PPT (apneogenic neuronal zone). Local microinjection of serotonin and noradrenaline into cholinergic PPT apneogenic zone evidenced their opposed impact through PPT on breathing, in contrast to their convergent regulatory role in behavioral state control (Saponjić et al., 2005a). Also, selective pharmacological stimulation by microinjection of DL-homocysteic acid defined four neuronal micro-circuitry approximately 500 microm in lenght of breathing-related neurons within the ventral respiratory group of medulla oblongata, which when stimulated produce different effects on respiratory rate, rhythm and amplitude, and on blood pressure. This study was the first high resolution study in order to

  10. Depressive symptoms, intrusive thoughts, sleep quality and sexual quality of life in women co-infected with human immunodeficiency virus and human papillomavirus.

    Science.gov (United States)

    Rose, Rachel C; Peake, Michele R; Ennis, Nicole; Pereira, Deidre B; Antoni, Michael H

    2005-12-01

    Women infected with human immunodeficiency virus (HIV) experience major challenges and often report marked decreases in sexual functioning and quality of life (QOL). HIV-infected women also face challenges concerned with other commonly observed concomitant sexually transmitted organisms, such as human papillomavirus (HPV), which may further affect sexual QOL. Despite advances made in understanding factors that predict sexual functioning and QOL in men with HIV, relatively little is understood about the role of behavioural and emotional factors in women. As a preliminary inquiry into this question, this study related depressive symptoms, AIDS-related intrusive thoughts and sleep quality with sexual QOL reports in 21 HIV+HPV+ women. We found that depressive symptoms, intrusive thoughts and sleep quality individually predicted poorer sexual QOL. Further analyses suggested that depression mediated the relationship between intrusive thoughts and sexual QOL. Implications for further work and clinical interventions to address depressive symptoms in this population are discussed.

  11. Human scalp recorded sigma activity is modulated by slow EEG oscillations during deep sleep.

    Science.gov (United States)

    Fell, Jürgen; Elfadil, Hakim; Röschke, Joachim; Burr, Wieland; Klaver, Peter; Elger, Christian E; Fernández, Guillén

    2002-07-01

    The EEG during deep sleep exhibits a distinct cortically generated slow oscillation of around and below 1 Hz which can be distinguished from other delta (0.5-3.5 Hz) activity. Intracranial studies showed that this slow oscillation triggers and groups cortical network firing. In the present study, we examined whether the phases of the slow oscillation during sleep stage 4 are correlated with the magnitude of sigma (12-16 Hz) and gamma (> 20 Hz) scalp activity. For this purpose, 10-min segments of uninterrupted stage 4 sleep EEG from 9 subjects were analyzed by applying wavelet techniques. We found that scalp recorded sigma, but not gamma, activity is modulated by the phases of the slow oscillation during deep sleep. Enhancement of sigma activity was observed to be triggered by the peak of the surface positive slow wave component, whereas reduction of sigma activity started around the peak of the negative component.

  12. Hierarchical nesting of slow oscillations, spindles and ripples in the human hippocampus during sleep

    NARCIS (Netherlands)

    Staresina, B.P.; Bergmann, T.O.; Bonnefond, M.; Meij, R. van der; Jensen, O.; Deuker, L.; Elger, C.E.; Axmacher, N.; Fell, J.

    2015-01-01

    During systems-level consolidation, mnemonic representations initially reliant on the hippocampus are thought to migrate to neocortical sites for more permanent storage, with an eminent role of sleep for facilitating this information transfer. Mechanistically, consolidation processes have been

  13. Community demographics and the propensity to report animal cruelty.

    Science.gov (United States)

    Taylor, Nicola; Signal, Tania D

    2006-01-01

    The last decade has seen an increased awareness concerning links between violence to nonhuman animals and violence to humans. This has resulted in a number of cross-reporting initiatives between family service providers and animal welfare organizations. The success of these initiatives rests on individuals being willing to report such violence. Thus, there is a need to determine which variables influence an individual's willingness to report deliberate animal cruelty and abuse. The aim of this study was to examine demographic and attitudinal variables to ascertain their impact on propensity to report deliberate animal harm. A telephone questionnaire resulted in 1,208 valid responses from members of the general community. Results showed a number of variables that affected the propensity to report: gender, occupation, and acknowledgment of the link between family violence and deliberate animal harm. This article discusses these variables and their implications.

  14. REM sleep phase preference in the crepuscular Octodon degus assessed by selective REM sleep deprivation.

    Science.gov (United States)

    Ocampo-Garcés, Adrián; Hernández, Felipe; Palacios, Adrian G

    2013-08-01

    To determine rapid eye movement (REM) sleep phase preference in a crepuscular mammal (Octodon degus) by challenging the specific REM sleep homeostatic response during the diurnal and nocturnal anticrepuscular rest phases. We have investigated REM sleep rebound, recovery, and documented REM sleep propensity measures during and after diurnal and nocturnal selective REM sleep deprivations. Nine male wild-captured O. degus prepared for polysomnographic recordings. Animals were recorded during four consecutive baseline and two separate diurnal or nocturnal deprivation days, under a 12:12 light-dark schedule. Three-h selective REM sleep deprivations were performed, starting at midday (zeitgeber time 6) or midnight (zeitgeber time 18). Diurnal and nocturnal REM sleep deprivations provoked equivalent amounts of REM sleep debt, but a consistent REM sleep rebound was found only after nocturnal deprivation. The nocturnal rebound was characterized by a complete recovery of REM sleep associated with an augment in REM/total sleep time ratio and enhancement in REM sleep episode consolidation. Our results support the notion that the circadian system actively promotes REM sleep. We propose that the sleep-wake cycle of O. degus is modulated by a chorus of circadian oscillators with a bimodal crepuscular modulation of arousal and a unimodal promotion of nocturnal REM sleep

  15. Babies in boxes and the missing links on safe sleep: Human evolution and cultural revolution.

    Science.gov (United States)

    Bartick, Melissa; Tomori, Cecília; Ball, Helen L

    2017-10-18

    Concerns about bedsharing as a risk for sudden infant death syndrome and other forms of sleep-associated infant death have gained prominence as a public health issue. Cardboard "baby boxes" are increasingly promoted to prevent infant death through separate sleep, despite no proof of efficacy. However, baby boxes disrupt "breastsleeping" (breastfeeding with co-sleeping) and may undermine breastfeeding. Recommendations enforcing separate sleep are based on 20th century Euro-American social norms for solitary infant sleep and scheduled feedings via bottles of cow's milk-based formula, in contrast to breastsleeping, an evolutionary adaptation facilitating the survival of mammalian infants for millennia. Interventions that aim to prevent bedsharing, such as the cardboard baby box, fail to consider the implications of evolutionary biology or of ethnocentrism in sleep guidance. Moreover, the focus on bedsharing neglects more potent risks such as smoking, drugs, alcohol, formula feeding, and poverty. Distribution of baby boxes may divert resources and attention away from addressing these other risk factors and lead to a false sense of security wherein we overlook that sudden unexplained infant deaths also occur in solitary sleep environments. Recognizing breastsleeping as the evolutionary and cross-cultural norm entails re-evaluating our research and policy priorities, such as providing greater structural support for families, supporting breastfeeding and safe co-sleeping, investigating ways to safely minimize separation for formula-fed infants, and mitigating the potential harms of mother-infant separation when breastsleeping is disrupted. Resources would be better spent addressing such questions rather than on a feel-good solution such as the baby box. © 2017 John Wiley & Sons Ltd.

  16. Experimental observation of a theoretically predicted nonlinear sleep spindle harmonic in human EEG.

    Science.gov (United States)

    Abeysuriya, R G; Rennie, C J; Robinson, P A; Kim, J W

    2014-10-01

    To investigate the properties of a sleep spindle harmonic oscillation previously predicted by a theoretical neural field model of the brain. Spindle oscillations were extracted from EEG data from nine subjects using an automated algorithm. The power and frequency of the spindle oscillation and the harmonic oscillation were compared across subjects. The bicoherence of the EEG was calculated to identify nonlinear coupling. All subjects displayed a spindle harmonic at almost exactly twice the frequency of the spindle. The power of the harmonic scaled nonlinearly with that of the spindle peak, consistent with model predictions. Bicoherence was observed at the spindle frequency, confirming the nonlinear origin of the harmonic oscillation. The properties of the sleep spindle harmonic were consistent with the theoretical modeling of the sleep spindle harmonic as a nonlinear phenomenon. Most models of sleep spindle generation are unable to produce a spindle harmonic oscillation, so the observation and theoretical explanation of the harmonic is a significant step in understanding the mechanisms of sleep spindle generation. Unlike seizures, sleep spindles produce nonlinear effects that can be observed in healthy controls, and unlike the alpha oscillation, there is no linearly generated harmonic that can obscure nonlinear effects. This makes the spindle harmonic a good candidate for future investigation of nonlinearity in the brain. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  17. Duration of activity and mode of action of modafinil: Studies on sleep and wakefulness in humans.

    Science.gov (United States)

    Turner, C; Belyavin, A J; Nicholson, A N

    2014-07-01

    The duration of activity of modafinil was investigated in healthy male volunteers in two double-blind crossover studies. Mode of action was explored using a statistical model concerned with the relationship between total sleep duration and that of rapid eye movement (REM) sleep. Nocturnal sleep (23:00-07:00) followed by next-day performance (09:00-17:00) was studied in 12 subjects administered 100, 200, 300 mg modafinil and placebo, 0.5 h before bedtime. Performance overnight (19:00-08:45) followed by sleep (09:15-15:15) was studied in nine subjects administered 100, 200, 300, 400 mg modafinil, 300 mg caffeine and placebo at 22:15. Modafinil dose-dependently reduced sleep duration (nocturnal: 200 mg, pmodafinil during overnight work varied with dose (200 mg>100 mg; 300, 400 mg>200, 100 mg, caffeine). However, in the study of next-day performance, the enhancement was attenuated at the highest dose (300 mg) by the greater disturbance of prior sleep. These findings indicate that modafinil has a long duration of action, with alerting properties arising predominantly from dopaminergic activity. © The Author(s) 2013.

  18. Sleep Disorders

    Science.gov (United States)

    ... the day, even if you have had enough sleep? You might have a sleep disorder. The most common kinds are Insomnia - a hard time falling or staying asleep Sleep apnea - breathing interruptions during sleep Restless legs syndrome - ...

  19. Investigation into the presence of human papillomavirus in patients with obstructive sleep apnea.

    Science.gov (United States)

    Baldwin, Brett J; Chitale, Dhananjay; Chen, Kang Mei; Worsham, Maria J; Yaremchuk, Kathleen

    2017-05-01

    The human papillomavirus (HPV) is known to infect the tissues of the oropharynx as demonstrated in HPV-positive oropharyngeal squamous cell carcinoma (OPSCC). HPV has also been shown to induce benign lymphoid hypertrophy. We sought to investigate an association between obstructive sleep apnea (OSA) and the presence of HPV in palatine and lingual tonsillar oropharyngeal tissue. Case series with chart review. This retrospective laboratory-based study of oropharyngeal tissue from patients with OSA included patients >18 years old who underwent surgical treatment for OSA at a single institution between January 2012 and May 2014. Surgical specimens of adequate size were analyzed for HPV6, 11, and 16 using real-time quantitative polymerase chain reaction from DNA extracted from formalin-fixed paraffin-embedded tissue blocks. Student t test, Pearson χ2 test, and linear logistic regression were used to assess comparisons of body mass index (BMI), apnea-hypopnea index (AHI), age, and gender between HPV-positive and HPV-negative groups. Of 99 cases included in the study, six were positive for HPV: two with HPV16 and four with HPV6. BMI, AHI, age, and gender showed no significant differences between the HPV-positive and HPV-negative groups. Logistic regression to predict HPV positivity accounting for each variable and multivariate analysis were not statistically significant. Our study did not show HPV to have a statistically significant association with OSA. None of the covariates analyzed (BMI, AHI, gender, age) predicted HPV positivity in surgically resected oropharyngeal tissue from OSA patients. 4 Laryngoscope, 127:1231-1234, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  20. Effects of dietary resveratrol on the sleep-wake cycle in the non-human primate gray mouse lemur (Microcebus murinus).

    Science.gov (United States)

    Pifferi, F; Rahman, A; Languille, S; Auffret, A; Babiloni, C; Blin, O; Lamberty, Y; Richardson, J C; Aujard, F

    2012-04-01

    Converging evidence shows that the non-human primate gray mouse lemur (Microcebus murinus) is ideal for the study of the aging process and for testing the effects of new therapies and dietary interventions on age-associated pathologies. One such dietary supplement is resveratrol (RSV), a dietary polyphenolic compound with several positive effects on metabolic functions and longevity. However, little is known about the effect of RSV on the lemur sleep-wake cycle, which reflects mammalian brain function and health. In the present study, the authors investigated this effect by comparing sleep-wake cycles in adult lemurs based on electroencephalographic (EEG) rhythms. The effect of short-term RSV supplementation on the sleep-wake cycle of mouse lemurs was evaluated in entrained conditions (long-day photoperiods, light:dark 14:10). After 3 wks of RSV supplementation, the animals exhibited a significantly increased proportion of active-wake time, occurring mainly during the resting phase of the sleep-wake cycle (+163%). The increase in active-wake time with RSV supplementation was accompanied by a significant reduction of both paradoxical sleep (-95%) and slow-wave sleep (-38%). These changes mainly occurred during the resting phase of the sleep-wake cycle (RSV supplementation induced negligible changes in active-wake time during the active phase of the sleep-wake cycle). The present data suggest that RSV may be a potent regulator of sleep-wake rhythms and could be of major interest in the study of sleep perturbations associated with aging and neuropathology.

  1. Local sleep and learning.

    Science.gov (United States)

    Huber, Reto; Ghilardi, M Felice; Massimini, Marcello; Tononi, Giulio

    2004-07-01

    Human sleep is a global state whose functions remain unclear. During much of sleep, cortical neurons undergo slow oscillations in membrane potential, which appear in electroencephalograms as slow wave activity (SWA) of sleep. It has been suggested that SWA homeostasis may reflect synaptic changes underlying a cellular need for sleep. If this were so, inducing local synaptic changes should induce local SWA changes, and these should benefit neural function. Here we show that sleep homeostasis indeed has a local component, which can be triggered by a learning task involving specific brain regions. Furthermore, we show that the local increase in SWA after learning correlates with improved performance of the task after sleep. Thus, sleep homeostasis can be induced on a local level and can benefit performance.

  2. The Neuroprotective Aspects of Sleep.

    Science.gov (United States)

    Eugene, Andy R; Masiak, Jolanta

    2015-03-01

    Sleep is an important component of human life, yet many people do not understand the relationship between the brain and the process of sleeping. Sleep has been proven to improve memory recall, regulate metabolism, and reduce mental fatigue. A minimum of 7 hours of daily sleep seems to be necessary for proper cognitive and behavioral function. The emotional and mental handicaps associated with chronic sleep loss as well as the highly hazardous situations which can be contributed to the lack of sleep is a serious concern that people need to be aware of. When one sleeps, the brain reorganizes and recharges itself, and removes toxic waste byproducts which have accumulated throughout the day. This evidence demonstrates that sleeping can clear the brain and help maintain its normal functioning. Multiple studies have been done to determine the effects of total sleep deprivation; more recently some have been conducted to show the effects of sleep restriction, which is a much more common occurrence, have the same effects as total sleep deprivation. Each phase of the sleep cycle restores and rejuvenates the brain for optimal function. When sleep is deprived, the active process of the glymphatic system does not have time to perform that function, so toxins can build up, and the effects will become apparent in cognitive abilities, behavior, and judgment. As a background for this paper we have reviewed literature and research of sleep phases, effects of sleep deprivation, and the glymphatic system of the brain and its restorative effect during the sleep cycle.

  3. Morning and evening physical exercise differentially regulate the autonomic nervous system during nocturnal sleep in humans.

    Science.gov (United States)

    Yamanaka, Yujiro; Hashimoto, Satoko; Takasu, Nana N; Tanahashi, Yusuke; Nishide, Shin-Ya; Honma, Sato; Honma, Ken-Ichi

    2015-11-01

    Effects of daily physical exercise in the morning or in the evening were examined on circadian rhythms in plasma melatonin and core body temperature of healthy young males who stayed in an experimental facility for 7 days under dim light conditions (exercise with a bicycle ergometer at ZT3 or at ZT10 for four consecutive days, where zeitgeber time 0 (ZT0) was the time of wake-up. The rising phase of plasma melatonin rhythm was delayed by 1.1 h without exercise. Phase-delay shifts of a similar extent were detected by morning and evening exercise. But the falling phase shifted only after evening exercise by 1.0 h. The sleep PSG did not change after morning exercise, while Stage 1+2 sleep significantly decreased by 13.0% without exercise, and RE sleep decreased by 10.5% after evening exercise. The nocturnal decline of rectal temperature was attenuated by evening exercise, but not by morning exercise. HRV during sleep changed differentially. Very low frequency (VLF) waves increased without exercise. VLF, low frequency (LF), and high frequency (HF) waves increased after morning exercise, whereas HR increased after evening exercise. Morning exercise eventually enhanced the parasympathetic activity, as indicated by HRV, while evening exercise activated the sympathetic activity, as indicated by increase in heart rate in the following nocturnal sleep. These findings indicated differential effects of morning and evening exercise on the circadian melatonin rhythm, PSG, and HRV. Copyright © 2015 the American Physiological Society.

  4. Effects of dawn simulation on markers of sleep inertia and post-waking performance in humans.

    Science.gov (United States)

    Thompson, Andrew; Jones, Helen; Gregson, Warren; Atkinson, Greg

    2014-05-01

    To examine the effects of a simulated dawn during the last 30 min of sleep on the subsequent dissipation of sleep inertia and changes in simulated work and physical performance. Eight participants, who reported difficulty with morning waking, were administered in a random order to a control (C) and a dawn simulation (DS) trial (starting 30 min prior to waking). Subjective ratings of sleep quality and alertness were obtained alongside measures of cognitive performance (addition and reaction time tasks measured at 5, 30 and 75 min after waking at habitual workday times). Physical performance was also measured 35 min after waking using a self-paced cycling protocol. After waking in DS, perceived sleep quality was 1.16 ± 0.89 (p = 0.01) points higher compared with C. Ratings of alertness were significantly higher in DS than C throughout the testing period (p = 0.04). Cognitive performance improved in both trials as time awake increased (p sleep can increase subjective alertness and improve both cognitive and physical performance after waking.

  5. Central adiposity and the propensity for rehearsal in children

    Directory of Open Access Journals (Sweden)

    Ling FCM

    2011-06-01

    Full Text Available Fiona CM Ling, Rich SW Masters, Clare CW Yu, Alison M McManusInstitute of Human Performance, The University of Hong Kong, Pokfulam, Hong KongBackground: There is increasing evidence that continuous activation of the hypothalamic-pituitary adrenal axis and the central sympathetic nervous system contributes to the pathogenesis of central adiposity via increased psychological stress. The purpose of this study was to examine the link between central adiposity and the propensity for Chinese children to rehearse emotionally upsetting events, a dimension of psychological stress. Additionally, gender differences in this relationship were explored.Methods: Waist circumference, which is a marker of central adiposity and associated risks of developing cardiovascular disease, was measured and the propensity for rehearsal was assessed twice over two consecutive years in Hong Kong Chinese children (n = 194, aged 7–9 years, using a psychometric tool.Results: Children with waist circumference indicative of a risk of cardiovascular disease displayed higher rehearsal scores than children categorized as “not at risk”, as did boys compared with girls. Our results suggest that central adiposity and the propensity for rehearsal of emotionally upsetting events may be linked in Chinese children.Conclusion: Future prospective studies examining the direction of causality between central adiposity and rehearsal can potentially have valuable clinical implications.Keywords: obesity, abdominal, stress, psychological, Hong Kong, child

  6. Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation

    OpenAIRE

    Irwin, DE; Olmstead, R; Carroll, JE

    2015-01-01

    © 2016 Society of Biological Psychiatry. Background Sleep disturbance is associated with inflammatory disease risk and all-cause mortality. Here, we assess global evidence linking sleep disturbance, sleep duration, and inflammation in adult humans. Methods A systematic search of English language publications was performed, with inclusion of primary research articles that characterized sleep disturbance and/or sleep duration or performed experimental sleep deprivation and assessed inflammation...

  7. Cortical deactivation induced by visual stimulation in human slow-wave sleep

    DEFF Research Database (Denmark)

    Born, Alfred Peter; Law, Ian; Lund, Torben E

    2002-01-01

    . It is unresolved whether this negative BOLD response pattern is of developmental neurobiological origin particular to a given age or to a general effect of sleep or sedative drugs. To further elucidate this issue, we used fMRI and positron emission tomography (PET) to study the brain activation pattern during...... that this decrease was secondary to a relative rCBF decrease. Possible mechanisms for the paradoxical response pattern during sleep include an active inhibition of the visual cortex or a disruption of an energy-consuming process...

  8. The relationship between the rate of melatonin excretion and sleep consolidation for locomotive engineers in natural sleep settings

    Directory of Open Access Journals (Sweden)

    Ferguson Sally

    2006-08-01

    Full Text Available Abstract Background The aim of the study was to examine the role that melatonin production plays in the regulation of sleep consolidation in a population of shiftworkers working and sleeping in their natural environments. Methods 253 locomotive engineers (249 male, 4 female, mean age = 39.7 years participated in the study for a 2-week period whilst working their normal roster patterns. Participants recorded details for all sleep periods in a sleep diary and collected urine samples during each day's main sleep period. The samples were subsequently assayed for the metabolite of melatonin in urine, 6-sulphatoxymelatonin (aMT6s, and the rate of excretion during main sleep periods was calculated. Results Separate one-way factorial ANOVAs revealed a significant effect of time of sleep onset on aMT6s excretion rate, sleep duration, and subjective sleep quality. Generally, the rate of aMT6s excretion was lower, sleep duration was shorter, and sleep quality was lower for sleeps initiated during the daytime than for sleeps initiated at night. Conclusion Combined with previous studies linking melatonin production and sleep propensity, and others demonstrating the relationship between sleep consolidation and melatonin production in forced desynchrony protocols, the current results indicate that low production of melatonin may play a role in the poor consolidation of daytime sleep in natural sleep settings.

  9. The Effects of Sleep Deprivation on Pain

    OpenAIRE

    Bernd Kundermann; Jürgen-Christian Krieg; Wolfgang Schreiber; Stefan Lautenbacher

    2004-01-01

    Chronic pain syndromes are associated with alterations in sleep continuity and sleep architecture. One perspective of this relationship, which has not received much attention to date, is that disturbances of sleep affect pain. To fathom this direction of cause, experimental human and animal studies on the effects of sleep deprivation on pain processing were reviewed. According to the majority of the studies, sleep deprivation produces hyperalgesic changes. Furthermore, sleep deprivation can c...

  10. The sequential propensity household projection model

    Directory of Open Access Journals (Sweden)

    Tom Wilson

    2013-04-01

    Full Text Available BACKGROUND The standard method of projecting living arrangements and households in Australia and New Zealand is the 'propensity model', a type of extended headship rate model. Unfortunately it possesses a number of serious shortcomings, including internal inconsistencies, difficulties in setting living arrangement assumptions, and very limited scenario creation capabilities. Data allowing the application of more sophisticated dynamic household projection models are unavailable in Australia. OBJECTIVE The aim was create a projection model to overcome these shortcomings whilst minimising input data requirements and costs, and retaining the projection outputs users are familiar with. METHODS The sequential propensity household projection model is proposed. Living arrangement projections take place in a sequence of calculations, with progressively more detailed living arrangement categories calculated in each step. In doing so the model largely overcomes the three serious deficiencies of the standard propensity model noted above. RESULTS The model is illustrated by three scenarios produced for one case study State, Queensland. They are: a baseline scenario in which all propensities are held constant to demonstrate the effects of population growth and ageing, a housing crisis scenario where housing affordability declines, and a prosperity scenario where families and individuals enjoy greater real incomes. A sensitivity analysis in which assumptions are varied one by one is also presented. CONCLUSIONS The sequential propensity model offers a more effective method of producing household and living arrangement projections than the standard propensity model, and is a practical alternative to dynamic projection models for countries and regions where the data and resources to apply such models are unavailable.

  11. The Transcriptional Repressor DEC2 Regulates Sleep Length in Mammals

    OpenAIRE

    He, Ying; Jones, Christopher R.; Fujiki, Nobuhiro; Xu, Ying; Guo, Bin; Holder, Jimmy L.; Rossner, Moritz J.; Nishino, Seiji; Fu, Ying-Hui

    2009-01-01

    Sleep deprivation can impair human health and performance. Habitual total sleep time and homeostatic sleep response to sleep deprivation are quantitative traits in humans. Genetic loci for these traits have been identified in model organisms, but none of these potential animal models have a corresponding human genotype and phenotype. We have identified a mutation in a transcriptional repressor (hDEC2-P385R) that is associated with a human short sleep phenotype. Activity profiles and sleep rec...

  12. Sex differences in light sensitivity impact on brightness perception, vigilant attention and sleep in humans

    National Research Council Canada - National Science Library

    Sarah L Chellappa; Roland Steiner; Peter Oelhafen; Christian Cajochen

    2017-01-01

    .... Here we investigated potential sex-differences to evening light exposure of 40 lx at 6500 K (blue-enriched) or at 2500 K (non-blue-enriched), and their impact on brightness perception, vigilant attention and sleep physiology...

  13. Independent circadian and sleep/wake regulation of adipokines and glucose in humans.

    Science.gov (United States)

    Shea, Steven A; Hilton, Michael F; Orlova, Christine; Ayers, R Timothy; Mantzoros, Christos S

    2005-05-01

    Leptin and adiponectin play important physiological roles in regulating appetite, food intake, and energy balance and have pathophysiological roles in obesity and anorexia nervosa. To assess the relative contributions of day/night patterns in behaviors (sleep/wake cycle and food intake) and of the endogenous circadian pacemaker on observed day/night patterns of adipokines, in six healthy subjects we measured circulating leptin, soluble leptin receptor, adiponectin, glucose, and insulin levels throughout a constant routine protocol (38 h of wakefulness with constant posture, temperature, and dim light, as well as identical snacks every 2 h) and throughout sleep and fasting periods before and after the constant routine. There were significant endogenous circadian rhythms in leptin, glucose, and insulin, with peaks around the usual time of awakening. Sleep/fasting resulted in additional systematic decreases in leptin, glucose, and insulin, whereas wakefulness/food intake resulted in a systematic increase in leptin. Thus, the day/night pattern in leptin is likely caused by combined effects from the endogenous circadian pacemaker and day/night patterns in behaviors. Our data imply that alterations in the sleep/wake schedule would lead to an increased daily range in circulating leptin, with lowest leptin upon awakening, which, by influencing food intake and energy balance, could be implicated in the increased prevalence of obesity in the shift work population.

  14. Human scalp recorded sigma activity is modulated by slow EEG oscillations during deep sleep.

    NARCIS (Netherlands)

    Fell, J.; Elfadil, H.; Roschke, J.; Burr, W.; Klaver, P.; Elger, C.E.; Fernandez, G.S.E.

    2002-01-01

    The EEG during deep sleep exhibits a distinct cortically generated slow oscillation of around and below 1 Hz which can be distinguished from other delta (0.5-3.5 Hz) activity. Intracranial studies showed that this slow oscillation triggers and groups cortical network firing. In the present study, we

  15. Transdermal Nicotine Patch Effects on EEG Power Spectra and Heart Rate Variability During Sleep of Healthy Male Adults

    OpenAIRE

    Choi, Jong-Bae; Lee, Yu-Jin G.; Jeong, Do-Un

    2017-01-01

    Objective The effect of transdermal nicotine patch on sleep physiology is not well established. The current study aimed to examine the influence of nicotine patch on homeostatic sleep propensity and autonomic nervous system. Methods We studied 16 non-smoking young healthy volunteers with nocturnal polysomnography in a double blind crossover design between sleep with and without nicotine patch. We compared the sleep variables, sleep EEG power spectra, and heart rate variability. Results The ni...

  16. Human performance under sustained operations and acute sleep deprivation conditions: toward a model of controlled attention.

    Science.gov (United States)

    Pilcher, June J; Band, David; Odle-Dusseau, Heather N; Muth, Eric R

    2007-05-01

    Although a number of studies have examined the effects of sleep deprivation on performance, the results are not easily explained. The purpose of the current study was to examine the effects of sustained operations and acute sleep deprivation on tasks that require a wide range of information processing. The current study also provided preliminary data on the use of the controlled attention model to better understand the effects of sleep deprivation. There were 24 college students who were paid to remain awake for one night and complete a variety of cognitive and vigilance tasks. Each task was administered four times during the night, once in each testing session (17:30-21:30, 21:45-01:45, 02:30-06:30, and 06:45-10:45). All tasks were counterbalanced across the testing sessions. The data were converted to z-scores and repeated-measures ANOVAs were completed. Performance did not significantly decrease on the more complex cognitive tasks over the night of sleep deprivation. Performance on the vigilance tasks decreased significantly across the night. Examining the characteristics of the cognitive tasks indicated that although they required different types of processing, they encouraged the participants to remain attentive to and engaged in the task. In contrast, the vigilance tasks were less intrinsically interesting and engaging. Thus, it seems likely that the participants were less capable of maintaining attention on the vigilance tasks than the cognitive tasks. These results indicate that a controlled attention model may be useful in better understanding the effects of sustained operations and sleep deprivation on performance.

  17. Propensity Score Matching within Prognostic Strata

    Science.gov (United States)

    Kelcey, Ben

    2013-01-01

    A central issue in nonexperimental studies is identifying comparable individuals to remove selection bias. One common way to address this selection bias is through propensity score (PS) matching. PS methods use a model of the treatment assignment to reduce the dimensionality of the covariate space and identify comparable individuals. parallel to…

  18. Authoritarian Parenting, Power Distance, and Bullying Propensity

    Science.gov (United States)

    Georgiou, Stelios N.; Stavrinides, Panayiotis; Fousiani, Kyriaki

    2013-01-01

    This study aimed at examining the existing relation among parenting, cultural value orientation, and bullying propensity at school. The participants (N = 231) were early adolescents randomly selected from 11 different schools in urban and rural areas of Cyprus. The results showed that a statistically significant relation exists between parental…

  19. A Dilemmas Task for Eliciting Risk Propensity

    Science.gov (United States)

    Botella, Juan; Narvaez, Maria; Martinez-Molina, Agustin; Rubio, Victor J.; Santacreu, Jose

    2008-01-01

    Risk propensity (RP) is a trait characterized by an increased probability of engaging in behaviors that have some potential danger or harm but also provide an opportunity for some benefit. In the present study, a new RP task with several dilemmas was explored. Each dilemma includes the initial set plus successive approximations for estimating the…

  20. RISKS MANAGEMENT. A PROPENSITY SCORE APPLICATION

    Directory of Open Access Journals (Sweden)

    Constangioara Alexandru

    2008-05-01

    Full Text Available Risk management is relatively unexplored in Romania. Although Romanian specialists dwell on theoretical aspects such as the risks classification and the important distinction between risks and uncertainty the practical relevance of the matter is outside existing studies. Present paper uses a dataset of consumer data to build a propensity scorecard based on relevant quantitative modeling.

  1. Partial REM-sleep deprivation increases the dream-like quality of mentation from REM sleep and sleep onset.

    Science.gov (United States)

    Nielsen, Tore; Stenstrom, Philippe; Takeuchi, Tomoka; Saucier, Sebastien; Lara-Carrasco, Jessica; Solomonova, Elizaveta; Martel, Emilie

    2005-09-01

    Sleep onset (SO) is cognitively and physiologically similar to rapid eye movement (REM) sleep, supporting the notion that REM sleep-related processes are 'covertly' active at this time. The objective was to determine if SO mentation is sensitive to REM sleep deprivation. Two-group cross-sectional design; sleep recordings for 3 nights. Standard sleep laboratory with 24-channel polysomnography recording. Fourteen female, 13 male healthy volunteers (18-41 yrs, mean=24.8 +/- 6.07). On Night 2, half were and half were not partially REM sleep-deprived (REMD), recalled REM mentation, and rated it for dream-like quality (DLQ), sleepiness, and sensory attributes. On Night 3, all were awakened from SO substages 4 and 5 for mentation reports and further ratings. REMD measures were derived from scored sleep tracings. REMD produced increases in DLQ for both REM and SO reports (P REM than for SO mentation (P REM/SO difference. Whereas 2 sensory attributes (presence of self, visual intensity) tended to distinguish the REM-mentation reports of REMD and control subjects, only 1, self-movement, distinguished their SO mentation reports (P REM and SO mentation was associated with increased sleepiness and decreased REM sleep time on Night 2. SO mentation responds to REMD much like REM mentation does, a finding consistent with other work supporting the notion of covert REM-sleep processes at SO. DLQ may be mediated by both increases in REM-sleep propensity and a circadian process indexed by sleepiness ratings.

  2. Cutaneous warming promotes sleep onset.

    NARCIS (Netherlands)

    Raymann, R.J.E.M.; Swaab, D.F.; Someren, E.J.W. van

    2005-01-01

    Sleep occurs in close relation to changes in body temperature. Both the monophasic sleep period in humans and the polyphasic sleep periods in rodents tend to be initiated when core body temperature is declining. This decline is mainly due to an increase in skin blood flow and consequently skin

  3. Sleep education during pregnancy for new mothers.

    Science.gov (United States)

    Kempler, Liora; Sharpe, Louise; Bartlett, Delwyn

    2012-12-17

    There is a high association between disturbed (poor quality) sleep and depression, which has lead to a consensus that there is a bidirectional relationship between sleep and mood. One time in a woman's life when sleep is commonly disturbed is during pregnancy and following childbirth. It has been suggested that sleep disturbance is another factor that may contribute to the propensity for women to become depressed in the postpartum period compared to other periods in their life. Post Natal Depression (PND) is common (15.5%) and associated with sleep disturbance, however, no studies have attempted to provide a sleep-focused intervention to pregnant women and assess whether this can improve sleep, and consequently maternal mood post-partum. The primary aim of this research is to determine the efficacy of a brief psychoeducational sleep intervention compared with a control group to improve sleep management, with a view to reduce depressive symptoms in first time mothers. This randomised controlled trial will recruit 214 first time mothers during the last trimester of their pregnancy. Participants will be randomised to receive either a set of booklets (control group) or a 3 hour psychoeducational intervention that focuses on sleep. The primary outcomes of this study are sleep-related, that is sleep quality and sleepiness for ten months following the birth of the baby. The secondary outcome is depressive symptoms. It is hypothesised that participants in the intervention group will have better sleep quality and sleepiness in the postpartum period than women in the control condition. Further, we predict that women who receive the sleep intervention will have lower depression scores postpartum compared with the control group. This study aims to provide an intervention that will improve maternal sleep in the postpartum period. If sleep can be effectively improved through a brief psychoeducational program, then it may have a protective role in reducing maternal postpartum

  4. REM Sleep Phase Preference in the Crepuscular Octodon degus Assessed by Selective REM Sleep Deprivation

    Science.gov (United States)

    Ocampo-Garcés, Adrián; Hernández, Felipe; Palacios, Adrian G.

    2013-01-01

    Study Objectives: To determine rapid eye movement (REM) sleep phase preference in a crepuscular mammal (Octodon degus) by challenging the specific REM sleep homeostatic response during the diurnal and nocturnal anticrepuscular rest phases. Design: We have investigated REM sleep rebound, recovery, and documented REM sleep propensity measures during and after diurnal and nocturnal selective REM sleep deprivations. Subjects: Nine male wild-captured O. degus prepared for polysomnographic recordings Interventions: Animals were recorded during four consecutive baseline and two separate diurnal or nocturnal deprivation days, under a 12:12 light-dark schedule. Three-h selective REM sleep deprivations were performed, starting at midday (zeitgeber time 6) or midnight (zeitgeber time 18). Measurements and Results: Diurnal and nocturnal REM sleep deprivations provoked equivalent amounts of REM sleep debt, but a consistent REM sleep rebound was found only after nocturnal deprivation. The nocturnal rebound was characterized by a complete recovery of REM sleep associated with an augment in REM/total sleep time ratio and enhancement in REM sleep episode consolidation. Conclusions: Our results support the notion that the circadian system actively promotes REM sleep. We propose that the sleep-wake cycle of O. degus is modulated by a chorus of circadian oscillators with a bimodal crepuscular modulation of arousal and a unimodal promotion of nocturnal REM sleep. Citation: Ocampo-Garcés A; Hernández F; Palacios AG. REM sleep phase preference in the crepuscular Octodon degus assessed by selective REM sleep deprivation. SLEEP 2013;36(8):1247-1256. PMID:23904685

  5. Physical exercise accelerates reentrainment of human sleep-wake cycle but not of plasma melatonin rhythm to 8-h phase-advanced sleep schedule.

    Science.gov (United States)

    Yamanaka, Yujiro; Hashimoto, Satoko; Tanahashi, Yusuke; Nishide, Shin-Ya; Honma, Sato; Honma, Ken-Ichi

    2010-03-01

    Effects of timed physical exercise were examined on the reentrainment of sleep-wake cycle and circadian rhythms to an 8-h phase-advanced sleep schedule. Seventeen male adults spent 12 days in a temporal isolation facility with dim light conditions (sleep schedule was phase-advanced by 8 h from their habitual sleep times for 4 days, which was followed by a free-run session for 6 days, during which the subjects were deprived of time cues. During the shift schedule, the exercise group (n = 9) performed physical exercise with a bicycle ergometer in the early and middle waking period for 2 h each. The control group (n = 8) sat on a chair at those times. Their sleep-wake cycles were monitored every day by polysomnography and/or weight sensor equipped with a bed. The circadian rhythm in plasma melatonin was measured on the baseline day before phase shift: on the 4th day of shift schedule and the 5th day of free-run. As a result, the sleep-onset on the first day of free-run in the exercise group was significantly phase-advanced from that in the control and from the baseline. On the other hand, the circadian melatonin rhythm was significantly phase-delayed in the both groups, showing internal desynchronization of the circadian rhythms. The sleep-wake cycle resynchronized to the melatonin rhythm by either phase-advance or phase-delay shifts in the free-run session. These findings indicate that the reentrainment of the sleep-wake cycle to a phase-advanced schedule occurs independent of the circadian pacemaker and is accelerated by timed physical exercise.

  6. Cortical deactivation induced by visual stimulation in human slow-wave sleep

    DEFF Research Database (Denmark)

    Born, Alfred Peter; Law, Ian; Lund, Torben E

    2002-01-01

    . It is unresolved whether this negative BOLD response pattern is of developmental neurobiological origin particular to a given age or to a general effect of sleep or sedative drugs. To further elucidate this issue, we used fMRI and positron emission tomography (PET) to study the brain activation pattern during...... and polysomnographically verified slow-wave sleep in a separate group of six subjects using H(2)(15)O PET measures of the regional cerebral blood flow (rCBF). This decrease was more rostro-dorsal compared to the relative rCBF increase along the calcarine sulcus found during visual stimulation in the awake state....... This study reconfirms the previously described paradoxical stimulation-correlated negative BOLD signal change in the rostro-medial occipital cortex, expanding this response mode to an age spectrum ranging from the newborn to the adult. Further, the use of complementary brain mapping techniques suggests...

  7. Human regional cerebral blood flow during rapid-eye-movement sleep

    DEFF Research Database (Denmark)

    Madsen, P L; Holm, S; Vorstrup, S

    1991-01-01

    CBF increased by 4% (p less than 0.01) in the associative visual area, while it decreased by 9% (p less than 0.01) in the inferior frontal cortex. The CBF increase in the associative visual area suggests that activation of cerebral structures processing complex visual material is correlated to visual...... dream experiences. On the other hand, the reduced involvement of the inferior frontal cortex observed during REM sleep might explain the poor temporal organization and bizarreness often experienced in dreams....

  8. Sleep and vascular disorders.

    Science.gov (United States)

    Plante, Gérard E

    2006-10-01

    It is not surprising that cardiovascular diseases such as congestive heart failure and coronary insufficiency can give rise to varying degrees of sleep impairment; it is less readily appreciated that certain physiologic events occurring during sleep-as well as long-term unsatisfactory sleep-may cause or increase the risk of cardiovascular conditions such as hypertension, atherosclerosis, stroke, and cardiac arrythmias. Heart rate abnormalities during sleep in normotensive subjects predict later cardiovascular disease, and their early identification alerts the physician to undertake preventive measures. Maneuvers, such as induction of hypoxia, can elicit abnormal blood pressure responses during sleep, and such responses have been used to identify impending cardiovascular problems that could become therapeutic targets. The spontaneously hypertensive rat has been used to examine the effect of sympathetic nervous system (SNS) activity on the heart under a variety of experimental conditions, including quiet and paradoxical sleep. The results have disclosed significant differences between the responses of spontaneously hypertensive rats and normal rats to SNS stimulation. Exploration of other pathophysiologic pathways affected by exposure to light and dark, including those responsive to the cyclic production of melatonin, will improve our understanding of the effect of disruptions of the circadian cycle on cardiovascular function. There is growing evidence that melatonin can influence important processes such as fluid, nitrogen, and acid-base balance. Human subjects whose nocturnal arterial blood pressure fails to show the "normal" decrement during sleep ("nondippers") are also prone to sleep poorly, exhibit increased SNS activity during sleep, and have an increased risk of total and cardiovascular disease mortality. Chronic sleep deficit is now known to be a risk factor for obesity and may contribute to the visceral form of obesity that underlies the metabolic syndrome

  9. Sleep Quiz

    Science.gov (United States)

    ... the radio up will keep the drowsy driver awake. _____5. Narcolepsy is a sleep disorder marked by " ... disturbed sleep. Sleeping during the day in a dark, quiet bedroom and getting exposure to sufficient bright ...

  10. Transdermal Nicotine Patch Effects on EEG Power Spectra and Heart Rate Variability During Sleep of Healthy Male Adults.

    Science.gov (United States)

    Choi, Jong-Bae; Lee, Yu-Jin G; Jeong, Do-Un

    2017-07-01

    The effect of transdermal nicotine patch on sleep physiology is not well established. The current study aimed to examine the influence of nicotine patch on homeostatic sleep propensity and autonomic nervous system. We studied 16 non-smoking young healthy volunteers with nocturnal polysomnography in a double blind crossover design between sleep with and without nicotine patch. We compared the sleep variables, sleep EEG power spectra, and heart rate variability. The night with nicotine patch showed significant increase in sleep latency, wake after sleep onset, and stage 1 sleep; and decrease in total sleep time, sleep efficiency, and percentage of REM sleep. Also, spectral analysis of the sleep EEG in the night with nicotine patch revealed decreased slow wave activity in stage 2 and REM sleep and increased alpha activity in the first NREM-REM sleep cycle. Heart rate variability showed no differences between the 2 nights, but the low to high ratio (a parameter indicative of sympathetic nervous system activity) positively correlated with wake after sleep onset in night with nicotine patch. Transdermal nicotine patch significantly disrupts sleep continuity, sleep architecture, and homeostatic sleep propensity. The overactivation of the sympathetic nervous system may be responsible for these changes.

  11. Youth Attitude Tracking Study: 1999 Propensity and Advertising Report

    National Research Council Canada - National Science Library

    Wilson, Miahael

    2000-01-01

    ... such as their future plans, current events, military recruiting advertising, and media habits. The primary focus of YATS has been to measure enlistment propensity-active duty, Reserve/National Guard, composite, and Service- specific propensity...

  12. Scale-free fluctuations in behavioral performance: delineating changes in spontaneous behavior of humans with induced sleep deficiency

    National Research Council Canada - National Science Library

    Ochab, Jeremi K; Tyburczyk, Jacek; Beldzik, Ewa; Chialvo, Dante R; Domagalik, Aleksandra; Fafrowicz, Magdalena; Gudowska-Nowak, Ewa; Marek, Tadeusz; Nowak, Maciej A; Oginska, Halszka; Szwed, Jerzy

    2014-01-01

    ...: during a week of regular sleep and a week of chronic partial sleep deprivation. After separating activity from rest with a pre-defined activity threshold, we have detected distinct statistical features of duration times of these two states...

  13. Erythroid-Specific Expression of β-globin from Sleeping Beauty-Transduced Human Hematopoietic Progenitor Cells

    Science.gov (United States)

    Sjeklocha, Lucas M.; Park, Chang-Won; Wong, Phillip Y-P; Roney, Mark J.; Belcher, John D.; Kaufman, Dan S.; Vercellotti, Gregory M.; Hebbel, Robert P.; Steer, Clifford J.

    2011-01-01

    Gene therapy for sickle cell disease will require efficient delivery of a tightly regulated and stably expressed gene product to provide an effective therapy. In this study we utilized the non-viral Sleeping Beauty (SB) transposon system using the SB100X hyperactive transposase to transduce human cord blood CD34+ cells with DsRed and a hybrid IHK–β-globin transgene. IHK transduced cells were successfully differentiated into multiple lineages which all showed transgene integration. The mature erythroid cells had an increased β-globin to γ-globin ratio from 0.66±0.08 to 1.05±0.12 (p = 0.05), indicating expression of β-globin from the integrated SB transgene. IHK–β-globin mRNA was found in non-erythroid cell types, similar to native β-globin mRNA that was also expressed at low levels. Additional studies in the hematopoietic K562 cell line confirmed the ability of cHS4 insulator elements to protect DsRed and IHK–β-globin transgenes from silencing in long-term culture studies. Insulated transgenes had statistically significant improvement in the maintenance of long term expression, while preserving transgene regulation. These results support the use of Sleeping Beauty vectors in carrying an insulated IHK–β-globin transgene for gene therapy of sickle cell disease. PMID:22216176

  14. Discrimination of Fearful and Angry Emotional Voices in Sleeping Human Neonates: a Study of the Mismatch Brain Responses

    Directory of Open Access Journals (Sweden)

    Dandan eZhang

    2014-12-01

    Full Text Available Appropriate processing of human voices with different threat-related emotions is of evolutionarily adaptive value for the survival of individuals. Nevertheless, it is still not clear whether the sensitivity to threat-related information is present at birth. Using an oddball paradigm, the current study investigated the neural correlates underlying automatic processing of emotional voices of fear and anger in sleeping neonates. Event-related potential data showed that the frontocentral scalp distribution of the neonatal brain could discriminate fearful voices from angry voices; the mismatch response (MMR was larger in response to the deviant stimuli of anger, compared with the standard stimuli of fear. Furthermore, this fear-anger MMR discrimination was observed only when neonates were in active sleep state. Although the neonates’ sensitivity to threat-related voices is not likely associated with a conceptual understanding of fearful and angry emotions, this special discrimination in early life may provide a foundation for later emotion and social cognition development.

  15. Sleep Disorders

    DEFF Research Database (Denmark)

    Rahbek Kornum, Birgitte; Mignot, Emmanuel

    2014-01-01

    in these networks create sleep disorders, including rapid eye movement sleep behavior disorder, sleep walking, and narcolepsy. Physiological changes associated with sleep can be imbalanced, resulting in excess movements such as periodic leg movements during sleep or abnormal breathing in obstructive sleep apneas......Mammalian sleep has evolved under the influence of the day-night cycle and in response to reproductive needs, food seeking, and predator avoidance, resulting in circadian (predictive) and homeostatic (reactive) regulation. A molecular clock characterized by transcription/translation feedback loops...... mediates circadian regulation of sleep. Misalignment with the rhythm of the sun results in circadian disorders and jet lag. The molecular basis of homeostatic sleep regulation is mostly unknown. A network of mutually inhibitory brain nuclei regulates sleep states and sleep-wake transitions. Abnormalities...

  16. Mechanisms used to restore ventilation after partial upper airway collapse during sleep in humans.

    Science.gov (United States)

    Jordan, Amy S; Wellman, Andrew; Heinzer, Raphael C; Lo, Yu-Lun; Schory, Karen; Dover, Louise; Gautam, Shiva; Malhotra, Atul; White, David P

    2007-10-01

    Most patients with obstructive sleep apnoea (OSA) can restore airflow after an obstructive respiratory event without arousal at least some of the time. The mechanisms that enable this ventilatory recovery are unclear but probably include increased upper airway dilator muscle activity and/or changes in respiratory timing. The aims of this study were to compare the ability to recover ventilation and the mechanisms of compensation following a sudden reduction of continuous positive airway pressure (CPAP) in subjects with and without OSA. Ten obese patients with OSA (mean (SD) apnoea-hypopnoea index 62.6 (12.4) events/h) and 15 healthy non-obese non-snorers were instrumented with intramuscular genioglossus electrodes and a mask/pneumotachograph which was connected to a modified CPAP device that could deliver either continuous positive or negative pressure. During stable non-rapid eye movement sleep the CPAP was repeatedly reduced 2-10 cm H2O below the level required to eliminate flow limitation and was held at this level for 5 min or until arousal from sleep occurred. During reduced CPAP the increases in genioglossus activity (311.5 (49.4)% of baseline in subjects with OSA and 315.4 (76.2)% of baseline in non-snorers, p = 0.9) and duty cycle (123.8 (3.9)% of baseline in subjects with OSA and 118.2 (2.8)% of baseline in non-snorers, p = 0.4) were similar in both groups, yet patients with OSA could restore ventilation without cortical arousal less often than non-snorers (54.1% vs 65.7% of pressure drops, p = 0.04). When ventilatory recovery did not occur, genioglossus muscle and respiratory timing changes still occurred but these did not yield adequate pharyngeal patency/ventilation. Compensatory mechanisms (increased genioglossus muscle activity and/or duty cycle) often restore ventilation during sleep but may be less effective in obese patients with OSA than in non-snorers.

  17. The Effects of Sleep Deprivation on Pain

    Directory of Open Access Journals (Sweden)

    Bernd Kundermann

    2004-01-01

    Full Text Available Chronic pain syndromes are associated with alterations in sleep continuity and sleep architecture. One perspective of this relationship, which has not received much attention to date, is that disturbances of sleep affect pain. To fathom this direction of cause, experimental human and animal studies on the effects of sleep deprivation on pain processing were reviewed. According to the majority of the studies, sleep deprivation produces hyperalgesic changes. Furthermore, sleep deprivation can counteract analgesic effects of pharmacological treatments involving opioidergic and serotoninergic mechanisms of action. The heterogeneity of the human data and the exclusive interest in rapid eye movement sleep deprivation in animals so far do not allow us to draw firm conclusions as to whether the hyperalgesic effects are due to the deprivation of specific sleep stages or whether they result from a generalized disruption of sleep continuity. The significance of opioidergic and serotoninergic processes as mediating mechanisms of the hyperalgesic changes produced by sleep deprivation are discussed.

  18. Sleep-dependent learning and memory consolidation.

    Science.gov (United States)

    Walker, Matthew P; Stickgold, Robert

    2004-09-30

    While the functions of sleep remain largely unknown, one of the most exciting and contentious hypotheses is that sleep contributes importantly to memory. A large number of studies offer a substantive body of evidence supporting this role of sleep in what is becoming known as sleep-dependent memory processing. This review will provide evidence of sleep-dependent memory consolidation and sleep-dependent brain plasticity and is divided into five sections: (1) an overview of sleep stages, memory categories, and the distinct stages of memory development; (2) a review of the specific relationships between sleep and memory, both in humans and animals; (3) a survey of evidence describing sleep-dependent brain plasticity, including human brain imaging studies as well as animal studies of cellular neurophysiology and molecular biology. We close (4) with a consideration of unanswered questions as well as existing arguments against the role of sleep in learning and memory and (5) a concluding summary.

  19. Sleep Characteristics in Children with Growth Hormone Deficiency

    National Research Council Canada - National Science Library

    Verrillo, Elisabetta; Bizzarri, Carla; Cappa, Marco; Bruni, Oliviero; Pavone, Martino; Ferri, Raffaele; Cutrera, Renato

    2011-01-01

    Background/Aims: Growth hormone (GH) is preferentially secreted during slow wave sleep and the interactions between human sleep and the somatotropic system are well documented, although only few studies have investigated the sleep EEG...

  20. Instrumental learning: An animal model for sleep dependent memory enhancement

    NARCIS (Netherlands)

    Leenaars, Cathalijn H. C.; Girardi, Carlos E. N.; Joosten, Ruud N. J. M. A.; Lako, Irene M.; Ruimschotel, Emma; Hanegraaf, Maaike A. J.; Dematteis, Maurice; Feenstra, Matthijs G. P.; van Someren, Eus J. W.

    2013-01-01

    The relationship between learning and sleep is multifaceted; learning influences subsequent sleep characteristics, which may in turn influence subsequent memory. Studies in humans indicate that sleep may not only prevent degradation of acquired memories, but even enhance performance without further

  1. Sleep deprivation impairs spatial retrieval but not spatial learning in the non-human primate grey mouse lemur.

    Directory of Open Access Journals (Sweden)

    Anisur Rahman

    Full Text Available A bulk of studies in rodents and humans suggest that sleep facilitates different phases of learning and memory process, while sleep deprivation (SD impairs these processes. Here we tested the hypothesis that SD could alter spatial learning and memory processing in a non-human primate, the grey mouse lemur (Microcebus murinus, which is an interesting model of aging and Alzheimer's disease (AD. Two sets of experiments were performed. In a first set of experiments, we investigated the effects of SD on spatial learning and memory retrieval after one day of training in a circular platform task. Eleven male mouse lemurs aged between 2 to 3 years were tested in three different conditions: without SD as a baseline reference, 8 h of SD before the training and 8 h of SD before the testing. The SD was confirmed by electroencephalographic recordings. Results showed no effect of SD on learning when SD was applied before the training. When the SD was applied before the testing, it induced an increase of the amount of errors and of the latency prior to reach the target. In a second set of experiments, we tested the effect of 8 h of SD on spatial memory retrieval after 3 days of training. Twenty male mouse lemurs aged between 2 to 3 years were tested in this set of experiments. In this condition, the SD did not affect memory retrieval. This is the first study that documents the disruptive effects of the SD on spatial memory retrieval in this primate which may serve as a new validated challenge to investigate the effects of new compounds along physiological and pathological aging.

  2. Cycle-Triggered Cortical Stimulation during Slow Wave Sleep Facilitates Learning a BMI Task: A Case Report in a Non-Human Primate.

    Science.gov (United States)

    Rembado, Irene; Zanos, Stavros; Fetz, Eberhard E

    2017-01-01

    Slow wave sleep (SWS) has been identified as the sleep stage involved in consolidating newly acquired information. A growing body of evidence has shown that delta (1-4 Hz) oscillatory activity, the characteristic electroencephalographic signature of SWS, is involved in coordinating interaction between the hippocampus and the neocortex and is thought to take a role in stabilizing memory traces related to a novel task. This case report describes a new protocol that uses neuroprosthetics training of a non-human primate to evaluate the effects of surface cortical electrical stimulation triggered from SWS cycles. The results suggest that stimulation phase-locked to SWS oscillatory activity promoted learning of the neuroprosthetic task. This protocol could be used to elucidate mechanisms of synaptic plasticity underlying off-line learning during sleep and offers new insights into the role of brain oscillations in information processing and memory consolidation.

  3. Acupuncture Improves Sleep Conditions of Minipigs Representing Diurnal Animals through an Anatomically Similar Point to the Acupoint (GV20 Effective for Humans

    Directory of Open Access Journals (Sweden)

    Ka-ichiro Takeishi

    2012-01-01

    Full Text Available Acupuncture, an alternative medicine, has been widely applied for people with sleep disturbances; therefore, the effects should be evaluated objectively. Micro-minipigs (MMPigs, the smallest miniature pigs for animal experiments, were used. Acupuncture was performed at two different points: Dafengmen is located on the head and is an anatomically similar point to human-Baihui (GV20, an effective acupoint for sleep disturbances in humans; pig-Baihui is on the back. The procedure was performed as follows: shallow, within 5 mm depth for several seconds; deep, 10–20 mm depth for 20 min. The sleep conditions were evaluated by actigraph, and the amount of catecholamine in pooled urine after acupuncture treatment. MMPigs with deep acupuncture at Dafengmen showed significantly efficient values on actigraph and catecholamine analysis as compared with untreated MMPigs. The effective acupoint for sleep conditions in the porcine model is at an anatomically similar point to humans, rather than the point determined by traditional Chinese medicine.

  4. Sleep inertia.

    Science.gov (United States)

    Tassi, Patricia; Muzet, Alain

    2000-08-01

    Sleep inertia is a transitional state of lowered arousal occurring immediately after awakening from sleep and producing a temporary decrement in subsequent performance. Many factors are involved in the characteristics of sleep inertia. The duration of prior sleep can influence the severity of subsequent sleep inertia. Although most studies have focused on sleep inertia after short naps, its effects can be shown after a normal 8-h sleep period. One of the most critical factors is the sleep stage prior to awakening. Abrupt awakening during a slow wave sleep (SWS) episode produces more sleep inertia than awakening in stage 1 or 2, REM sleep being intermediate. Therefore, prior sleep deprivation usually enhances sleep inertia since it increases SWS. There is no direct evidence that sleep inertia exhibits a circadian rhythm. However, it seems that sleep inertia is more intense when awakening occurs near the trough of the core body temperature as compared to its circadian peak. A more controversial issue concerns the time course of sleep inertia. Depending on the studies, it can last from 1 min to 4 h. However, in the absence of major sleep deprivation, the duration of sleep inertia rarely exceeds 30 min. But all these results should be analysed as a function of type of task and dependent variables. Different cognitive functions are probably not sensitive to the same degree to sleep inertia and special attention should be provided to dependent variables as a result of the cognitive processes under review. Finally, sleep disorders represent risk factors which deserve new insight in treatment strategies to counteract the adverse effects of sleep inertia.

  5. Nonstandard Work Schedules and Developmentally Generative Parenting Practices: An Application of Propensity Score Techniques

    Science.gov (United States)

    Grzywacz, Joseph G.; Daniel, Stephanie S.; Tucker, Jenna; Walls, Jill; Leerkes, Esther

    2011-01-01

    Data from the National Institute for Child Health and Human Development Study of Early Child Care (Phase I) and propensity score techniques were used to determine whether working full time in a nonstandard schedule job during the child's first year predicted parenting practices over 3 years. Results indicated that women who worked full time in a…

  6. BMI, eating habits and sleep in relation to salivary counts of mutans streptococci in children - the IDEFICS Sweden study

    National Research Council Canada - National Science Library

    Arvidsson, Louise; Birkhed, Dowen; Hunsberger, Monica; Lanfer, Anne; Lissner, Lauren; Mehlig, Kirsten; Mårild, Staffan; Eiben, Gabriele

    .... Cross-sectional study investigating salivary counts of MS, BMI Z-score, waist circumference, meal frequency, sugar propensity and sleep duration, in children. West Sweden. Children (n 271) aged 4-11 years...

  7. Skin Temperature Rhythms in Humans Respond to Changes in the Timing of Sleep and Light.

    Science.gov (United States)

    Cuesta, Marc; Boudreau, Philippe; Cermakian, Nicolas; Boivin, Diane B

    2017-06-01

    Body temperature is known to vary with circadian phase and to be influenced by factors that can mask its circadian expression. We wanted to test whether skin temperature rhythms were sensitive to an abrupt shift of the sleep schedule and to the resetting effects of light. Nineteen healthy subjects spent 6 days in time isolation and underwent a simulated night-shift procedure. They were assigned to either a control group ( n = 10) or bright light group ( n = 9) and measurements were taken under a baseline day-oriented schedule and during the 4(th) cycle of a night-oriented schedule. In the bright light group, participants were exposed to a 3-cycle 8-h exposure of ~6,500 lux at night, while the control group remained in dim light conditions (~3 lux). Skin temperature was recorded in 10 and 4 participants from the control and bright light groups, respectively. We found significant circadian rhythms of plasma melatonin, core body temperature (CBT), and skin temperature at baseline for both groups ( p skin temperature following night shifts were significantly phase delayed by about 7 to 9 h ( p skin temperature and subsequent decrease in CBT, in contrast to what has been previously reported. The present study shows that, in constant posture conditions, skin temperature rhythms have an evoked component sensitive to abrupt changes in the timing of sleep. They also comprise an endogenous component that is sensitive to the resetting effects of bright light exposure. These results have applications for the determination of circadian phase, as skin temperature is less intrusive than rectal temperature recordings.

  8. Sleep deprivation impairs object recognition in mice

    NARCIS (Netherlands)

    Palchykova, S; Winsky-Sommerer, R; Meerlo, P; Durr, R; Tobler, Irene

    2006-01-01

    Many studies in animals and humans suggest that sleep facilitates learning, memory consolidation, and retrieval. Moreover, sleep deprivation (SD) incurred after learning, impaired memory in humans, mice, rats, and hamsters. We investigated the importance of sleep and its timing in in object

  9. Genetic variants in human CLOCK associate with total energy intake and cytokine sleep factors in overweight subjects (GOLDN population).

    Science.gov (United States)

    Garaulet, Marta; Lee, Yu-Chi; Shen, Jian; Parnell, Laurence D; Arnett, Donna K; Tsai, Michael Y; Lai, Chao-Qiang; Ordovas, Jose M

    2010-03-01

    Despite the importance of total energy intake in circadian system regulation, no study has related human CLOCK gene polymorphisms and food-intake measures. The aim of this study was to analyze the associations of CLOCK single-nucleotide polymorphisms (SNPs) with food intake and to explore the specific role of the cytokine system. A total of 1100 individual participants in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) study were included. Dietary intake was estimated with a validated questionnaire. Interleukin-6 (IL-6), monocyte chemotactic protein 1 (MCP1), tumor necrosis factor-alpha (TNF-alpha), IL-2 soluble receptor-alpha (IL-2sR-alpha) and adiponectin plasma concentrations were measured. Our results showed that four of five CLOCK SNPs selected were significantly associated with total energy intake (PSNP rs3749474, the energy intake and total fat, protein and carbohydrate intakes were significantly higher in minor allele carriers than in non-carriers. Frequency of the minor allele was greater in subjects with high energy intake than in those with low intake. Subjects with the minor allele were 1.33 times more likely to have high energy intake than non-carriers (95% CI 1.09-1.72, P=0.0350). All CLOCK SNPs were associated with plasma cytokine values, in particular with those that were highly correlated with energy intake: MCP1, IL-6 and adiponectin. Interestingly, minor allele carriers with high energy intake showed decreased cytokine values, which could be related with a lower anorectic effect and decreased sleep in these subjects. In conclusion, we show a novel association of genetic variation at CLOCK with total energy intake, which was particularly relevant for SNP rs3749474. Associations could be mediated through the alteration of cytokine levels that may influence energy intake and sleep pattern.

  10. Partial sleep restriction activates immune response-related gene expression pathways: experimental and epidemiological studies in humans.

    Directory of Open Access Journals (Sweden)

    Vilma Aho

    Full Text Available Epidemiological studies have shown that short or insufficient sleep is associated with increased risk for metabolic diseases and mortality. To elucidate mechanisms behind this connection, we aimed to identify genes and pathways affected by experimentally induced, partial sleep restriction and to verify their connection to insufficient sleep at population level. The experimental design simulated sleep restriction during a working week: sleep of healthy men (N = 9 was restricted to 4 h/night for five nights. The control subjects (N = 4 spent 8 h/night in bed. Leukocyte RNA expression was analyzed at baseline, after sleep restriction, and after recovery using whole genome microarrays complemented with pathway and transcription factor analysis. Expression levels of the ten most up-regulated and ten most down-regulated transcripts were correlated with subjective assessment of insufficient sleep in a population cohort (N = 472. Experimental sleep restriction altered the expression of 117 genes. Eight of the 25 most up-regulated transcripts were related to immune function. Accordingly, fifteen of the 25 most up-regulated Gene Ontology pathways were also related to immune function, including those for B cell activation, interleukin 8 production, and NF-κB signaling (P<0.005. Of the ten most up-regulated genes, expression of STX16 correlated negatively with self-reported insufficient sleep in a population sample, while three other genes showed tendency for positive correlation. Of the ten most down-regulated genes, TBX21 and LGR6 correlated negatively and TGFBR3 positively with insufficient sleep. Partial sleep restriction affects the regulation of signaling pathways related to the immune system. Some of these changes appear to be long-lasting and may at least partly explain how prolonged sleep restriction can contribute to inflammation-associated pathological states, such as cardiometabolic diseases.

  11. Diminished brain glucose metabolism is a significant determinant for falling rates of systemic glucose utilization during sleep in normal humans.

    OpenAIRE

    Boyle, P. J.; J. C. Scott; Krentz, A J; Nagy, R J; Comstock, E; Hoffman, C

    1994-01-01

    Systemic glucose utilization declines during sleep in man. We tested the hypothesis that this decline in utilization is largely accounted for by reduced brain glucose metabolism. 10 normal subjects underwent internal jugular and radial artery cannulation to determine cerebral blood flow by N2O equilibrium technique and to quantitate cross-brain glucose and oxygen differences before and every 3 h during sleep. Sleep stage was graded by continuous electroencephalogram, and systemic glucose turn...

  12. Jaw-opening reflex and corticobulbar motor excitability changes during quiet sleep in non-human primates

    DEFF Research Database (Denmark)

    Yao, Dongyuan; Lavigne, Gilles J.; Lee, Jye-Chang

    2013-01-01

    Study Objective: To test the hypothesis that the reflex and corticobulbar motor excitability of jaw muscles is reduced during sleep. Design: Polysomnographic recordings in the electrophysiological study. Setting: University sleep research laboratories. Participants and Interventions: The reflex...... and corticobulbar motor excitability of jaw muscles was determined during the quiet awake state (QW) and quiet sleep (QS) in monkeys (n = 4). Measurements and Results: During QS sleep, compared to QW periods, both tongue stimulation-evoked jaw-opening reflex peak and root mean square amplitudes were significantly......-evoked activity in the jaw motor system is depressed during QS....

  13. Cerebral O2 metabolism and cerebral blood flow in humans during deep and rapid-eye-movement sleep

    DEFF Research Database (Denmark)

    Madsen, P L; Schmidt, J F; Wildschiødtz, Gordon

    1991-01-01

    It could be expected that the various stages of sleep were reflected in variation of the overall level of cerebral activity and thereby in the magnitude of cerebral metabolic rate of oxygen (CMRO2) and cerebral blood flow (CBF). The elusive nature of sleep imposes major methodological restrictions...... on examination of this question. We have now measured CBF and CMRO2 in young healthy volunteers using the Kety-Schmidt technique with 133Xe as the inert gas. Measurements were performed during wakefulness, deep sleep (stage 3/4), and rapid-eye-movement (REM) sleep as verified by standard polysomnography...

  14. Partial sleep restriction activates immune response-related gene expression pathways: experimental and epidemiological studies in humans.

    Science.gov (United States)

    Aho, Vilma; Ollila, Hanna M; Rantanen, Ville; Kronholm, Erkki; Surakka, Ida; van Leeuwen, Wessel M A; Lehto, Maili; Matikainen, Sampsa; Ripatti, Samuli; Härmä, Mikko; Sallinen, Mikael; Salomaa, Veikko; Jauhiainen, Matti; Alenius, Harri; Paunio, Tiina; Porkka-Heiskanen, Tarja

    2013-01-01

    Epidemiological studies have shown that short or insufficient sleep is associated with increased risk for metabolic diseases and mortality. To elucidate mechanisms behind this connection, we aimed to identify genes and pathways affected by experimentally induced, partial sleep restriction and to verify their connection to insufficient sleep at population level. The experimental design simulated sleep restriction during a working week: sleep of healthy men (N = 9) was restricted to 4 h/night for five nights. The control subjects (N = 4) spent 8 h/night in bed. Leukocyte RNA expression was analyzed at baseline, after sleep restriction, and after recovery using whole genome microarrays complemented with pathway and transcription factor analysis. Expression levels of the ten most up-regulated and ten most down-regulated transcripts were correlated with subjective assessment of insufficient sleep in a population cohort (N = 472). Experimental sleep restriction altered the expression of 117 genes. Eight of the 25 most up-regulated transcripts were related to immune function. Accordingly, fifteen of the 25 most up-regulated Gene Ontology pathways were also related to immune function, including those for B cell activation, interleukin 8 production, and NF-κB signaling (Pimmune system. Some of these changes appear to be long-lasting and may at least partly explain how prolonged sleep restriction can contribute to inflammation-associated pathological states, such as cardiometabolic diseases.

  15. Role of sleep and circadian disruption on energy expenditure and in metabolic predisposition to human obesity and metabolic disease.

    Science.gov (United States)

    McHill, A W; Wright, K P

    2017-02-01

    Weight gain, obesity and diabetes have reached alarming levels in the developed world. Traditional risk factors such as over-eating, poor nutritional choices and lack of exercise cannot fully account for the high prevalence of metabolic disease. This review paper examines the scientific evidence on two novel risk factors that contribute to dys-regulated metabolic physiology: sleep disruption and circadian misalignment. Specifically, fundamental relationships between energy metabolism and sleep and circadian rhythms and the impact of sleep and circadian disruption on metabolic physiology are examined. Millions of individuals worldwide do not obtain sufficient sleep for healthy metabolic function, and many participate in shift work and social activities at times when the internal physiological clock is promoting sleep. These behaviours predispose an individual for poor metabolic health by promoting excess caloric intake in response to reduced sleep, food intake at internal biological times when metabolic physiology is not prepared, decreased energy expenditure when wakefulness and sleep are initiated at incorrect internal biological times, and disrupted glucose metabolism during short sleep and circadian misalignment. In addition to the traditional risk factors of poor diet and exercise, disturbed sleep and circadian rhythms represent modifiable risk factors for prevention and treatment of metabolic disease and for promotion of healthy metabolism. © 2017 World Obesity Federation.

  16. Self-organized dynamical complexity in human wakefulness and sleep: Different critical brain-activity feedback for conscious and unconscious states

    Science.gov (United States)

    Allegrini, Paolo; Paradisi, Paolo; Menicucci, Danilo; Laurino, Marco; Piarulli, Andrea; Gemignani, Angelo

    2015-09-01

    Criticality reportedly describes brain dynamics. The main critical feature is the presence of scale-free neural avalanches, whose auto-organization is determined by a critical branching ratio of neural-excitation spreading. Other features, directly associated to second-order phase transitions, are: (i) scale-free-network topology of functional connectivity, stemming from suprathreshold pairwise correlations, superimposable, in waking brain activity, with that of ferromagnets at Curie temperature; (ii) temporal long-range memory associated to renewal intermittency driven by abrupt fluctuations in the order parameters, detectable in human brain via spatially distributed phase or amplitude changes in EEG activity. Herein we study intermittent events, extracted from 29 night EEG recordings, including presleep wakefulness and all phases of sleep, where different levels of mentation and consciousness are present. We show that while critical avalanching is unchanged, at least qualitatively, intermittency and functional connectivity, present during conscious phases (wakefulness and REM sleep), break down during both shallow and deep non-REM sleep. We provide a theory for fragmentation-induced intermittency breakdown and suggest that the main difference between conscious and unconscious states resides in the backwards causation, namely on the constraints that the emerging properties at large scale induce to the lower scales. In particular, while in conscious states this backwards causation induces a critical slowing down, preserving spatiotemporal correlations, in dreamless sleep we see a self-organized maintenance of moduli working in parallel. Critical avalanches are still present, and establish transient auto-organization, whose enhanced fluctuations are able to trigger sleep-protecting mechanisms that reinstate parallel activity. The plausible role of critical avalanches in dreamless sleep is to provide a rapid recovery of consciousness, if stimuli are highly arousing.

  17. The Effects of Sleep Continuity Disruption on Positive Mood and Sleep Architecture in Healthy Adults.

    Science.gov (United States)

    Finan, Patrick H; Quartana, Phillip J; Smith, Michael T

    2015-11-01

    The purpose of this study was to test an experimental model of the effects of sleep continuity disturbance on sleep architecture and positive mood in order to better understand the mechanisms linking insomnia and depression. Participants were randomized to receive 3 consecutive nights of sleep continuity disruption via forced nocturnal awakenings (FA, n = 21), or one of two control conditions: restricted sleep opportunity (RSO, n = 17) or uninterrupted sleep (US, n = 24). The study was set in an inpatient clinical research suite. Healthy, good-sleeping men and women were included. Polysomnography was used to measure sleep architecture, and mood was assessed via self-report each day. Compared to restricted sleep opportunity controls, forced awakenings subjects had significantly less slow wave sleep (P < 0.05) after the first night of sleep deprivation, and significantly lower positive mood (P < 0.05) after the second night of sleep deprivation. The differential change in slow wave sleep statistically mediated the observed group differences in positive mood (P = 0.002). To our knowledge, this is the first human experimental study to demonstrate that, despite comparable reductions in total sleep time, partial sleep loss from sleep continuity disruption is more detrimental to positive mood than partial sleep loss from delaying bedtime, even when controlling for concomitant increases in negative mood. With these findings, we provide temporal evidence in support of a putative biologic mechanism (slow wave sleep deficit) that could help explain the strong comorbidity between insomnia and depression. © 2015 Associated Professional Sleep Societies, LLC.

  18. SLEEP DEPRIVATION AND CARDIOVASCULAR RISK

    Directory of Open Access Journals (Sweden)

    V. А. Vizir

    2013-06-01

    Full Text Available In a review article extensively discusses the relationship between sleep duration and cardiovascular diseases. Sleep loss is a common condition in developed countries, with evidence showing that people in Western countries are sleeping on average only 6.8 hour per night, 1.5 hour less than a century ago. Although the effect of sleep deprivation on the human body is not completely unexplained, recent epidemiological studies have revealed relationships between sleep deprivation and arterial hypertension, coronary heart disease and diabetes mellitus. Increased sympathetic nervous system activity and changes in melatonin secretion are considered as the main pathophysiological mechanisms involved in the development and progression of cardiovascular disease in patients with insufficient duration of nighttime sleep. Adequate sleep duration may be important for preventing cardiovascular diseases in modern society.

  19. Respiratory syncytial virus (RSV) and its propensity for causing bronchiolitis.

    Science.gov (United States)

    Pickles, Raymond J; DeVincenzo, John P

    2015-01-01

    Infants and young children with acute onset of wheezing and reduced respiratory airflows are often diagnosed with obstruction and inflammation of the small bronchiolar airways, ie bronchiolitis. The most common aetological agents causing bronchiolitis in young children are the respiratory viruses, and of the commonly encountered respiratory viruses, respiratory syncytial virus (RSV) has a propensity for causing bronchiolitis. Indeed, RSV bronchiolitis remains the major reason why previously healthy infants are admitted to hospital. Why RSV infection is such a predominant cause of bronchiolitis is the subject of this review. By reviewing the available histopathology of RSV bronchiolitis, both in humans and relevant animal models, we identify hallmark features of RSV infection of the distal airways and focus attention on the consequences of columnar cell cytopathology occurring in the bronchioles, which directly impacts the development of bronchiolar obstruction, inflammation and disease. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  20. Obstructive Sleep Apnea

    Science.gov (United States)

    ... to find out more. Obstructive Sleep Apnea Obstructive Sleep Apnea Obstructive sleep apnea (OSA) is a serious ... to find out more. Obstructive Sleep Apnea Obstructive Sleep Apnea Obstructive sleep apnea (OSA) is a serious ...

  1. Is Sleep Essential for Neural Plasticity in Humans, and How Does It Affect Motor and Cognitive Recovery?

    Directory of Open Access Journals (Sweden)

    Maurizio Gorgoni

    2013-01-01

    Full Text Available There is a general consensus that sleep is strictly linked to memory, learning, and, in general, to the mechanisms of neural plasticity, and that this link may directly affect recovery processes. In fact, a coherent pattern of empirical findings points to beneficial effect of sleep on learning and plastic processes, and changes in synaptic plasticity during wakefulness induce coherent modifications in EEG slow wave cortical topography during subsequent sleep. However, the specific nature of the relation between sleep and synaptic plasticity is not clear yet. We reported findings in line with two models conflicting with respect to the underlying mechanisms, that is, the “synaptic homeostasis hypothesis” and the “consolidation” hypothesis, and some recent results that may reconcile them. Independently from the specific mechanisms involved, sleep loss is associated with detrimental effects on plastic processes at a molecular and electrophysiological level. Finally, we reviewed growing evidence supporting the notion that plasticity-dependent recovery could be improved managing sleep quality, while monitoring EEG during sleep may help to explain how specific rehabilitative paradigms work. We conclude that a better understanding of the sleep-plasticity link could be crucial from a rehabilitative point of view.

  2. Is sleep essential for neural plasticity in humans, and how does it affect motor and cognitive recovery?

    Science.gov (United States)

    Gorgoni, Maurizio; D'Atri, Aurora; Lauri, Giulia; Rossini, Paolo Maria; Ferlazzo, Fabio; De Gennaro, Luigi

    2013-01-01

    There is a general consensus that sleep is strictly linked to memory, learning, and, in general, to the mechanisms of neural plasticity, and that this link may directly affect recovery processes. In fact, a coherent pattern of empirical findings points to beneficial effect of sleep on learning and plastic processes, and changes in synaptic plasticity during wakefulness induce coherent modifications in EEG slow wave cortical topography during subsequent sleep. However, the specific nature of the relation between sleep and synaptic plasticity is not clear yet. We reported findings in line with two models conflicting with respect to the underlying mechanisms, that is, the "synaptic homeostasis hypothesis" and the "consolidation" hypothesis, and some recent results that may reconcile them. Independently from the specific mechanisms involved, sleep loss is associated with detrimental effects on plastic processes at a molecular and electrophysiological level. Finally, we reviewed growing evidence supporting the notion that plasticity-dependent recovery could be improved managing sleep quality, while monitoring EEG during sleep may help to explain how specific rehabilitative paradigms work. We conclude that a better understanding of the sleep-plasticity link could be crucial from a rehabilitative point of view.

  3. Consequences of sleep deprivation.

    Science.gov (United States)

    Orzeł-Gryglewska, Jolanta

    2010-01-01

    This paper presents the history of research and the results of recent studies on the effects of sleep deprivation in animals and humans. Humans can bear several days of continuous sleeplessness, experiencing deterioration in wellbeing and effectiveness; however, also a shorter reduction in the sleep time may lead to deteriorated functioning. Sleeplessness accounts for impaired perception, difficulties in keeping concentration, vision disturbances, slower reactions, as well as the appearance of microepisodes of sleep during wakefulness which lead to lower capabilities and efficiency of task performance and to increased number of errors. Sleep deprivation results in poor memorizing, schematic thinking, which yields wrong decisions, and emotional disturbances such as deteriorated interpersonal responses and increased aggressiveness. The symptoms are accompanied by brain tissue hypometabolism, particularly in the thalamus, prefrontal, frontal and occipital cortex and motor speech centres. Sleep deficiency intensifies muscle tonus and coexisting tremor, speech performance becomes monotonous and unclear, and sensitivity to pain is higher. Sleeplessness also relates to the changes in the immune response and the pattern of hormonal secretion, of the growth hormone in particular. The risk of obesity, diabetes and cardiovascular disease increases. The impairment of performance which is caused by 20-25 hours of sleeplessness is comparable to that after ethanol intoxication at the level of 0.10% blood alcohol concentration. The consequences of chronic sleep reduction or a shallow sleep repeated for several days tend to accumulate and resemble the effects of acute sleep deprivation lasting several dozen hours. At work, such effects hinder proper performance of many essential tasks and in extreme situations (machine operation or vehicle driving), sleep loss may be hazardous to the worker and his/her environment.

  4. Sleep and Sleep Homeostasis in Mice Lacking the 5-HT2c Receptor

    OpenAIRE

    Frank, Marcos G.; Stryker, Michael P.; Tecott, Laurence H.

    2002-01-01

    Studies in humans and rats indicate that serotonin (5-hydroxytryptamine, 5-HT) receptors are involved in mammalian sleep expression. We investigated the contribution of the 5-HT2c receptor to sleep expression by examining sleep patterns in mice bearing a targeted null mutation of this receptor. 5-HT2c receptor knock-out mice had more wakefulness, several abnormalities in rapid eye movement sleep expression and an enhanced response to sleep deprivation compared with wild-type control mice. The...

  5. Youth Attitude Tracking Study: 1998 Propensity and Advertising Report

    National Research Council Canada - National Science Library

    Wilson, Michael

    2000-01-01

    .... Findings cover results from questions on enlistment propensity, advertising awareness, recruiter contact, slogan recognition, media habits, and Internet usage among 16- to 24- year-old American youth...

  6. Youth Attitude Tracking Study 1997: Propensity and Advertising Report

    National Research Council Canada - National Science Library

    Wilson, Michael

    1998-01-01

    .... Findings cover results from questions on enlistment propensity, advertising awareness, recruiter contact, slogan recognition, media habits, and Internet usage among 16- to 24- year-old American youth...

  7. A nap to recap or how reward regulates hippocampal-prefrontal memory networks during daytime sleep in humans.

    Science.gov (United States)

    Igloi, Kinga; Gaggioni, Giulia; Sterpenich, Virginie; Schwartz, Sophie

    2015-10-16

    Sleep plays a crucial role in the consolidation of newly acquired memories. Yet, how our brain selects the noteworthy information that will be consolidated during sleep remains largely unknown. Here we show that post-learning sleep favors the selectivity of long-term consolidation: when tested three months after initial encoding, the most important (i.e., rewarded, strongly encoded) memories are better retained, and also remembered with higher subjective confidence. Our brain imaging data reveals that the functional interplay between dopaminergic reward regions, the prefrontal cortex and the hippocampus contributes to the integration of rewarded associative memories. We further show that sleep spindles strengthen memory representations based on reward values, suggesting a privileged replay of information yielding positive outcomes. These findings demonstrate that post-learning sleep determines the neural fate of motivationally-relevant memories and promotes a value-based stratification of long-term memory stores.

  8. Rotating waves during human sleep spindles organize global patterns of activity that repeat precisely through the night

    Science.gov (United States)

    Muller, Lyle; Piantoni, Giovanni; Koller, Dominik; Cash, Sydney S; Halgren, Eric; Sejnowski, Terrence J

    2016-01-01

    During sleep, the thalamus generates a characteristic pattern of transient, 11-15 Hz sleep spindle oscillations, which synchronize the cortex through large-scale thalamocortical loops. Spindles have been increasingly demonstrated to be critical for sleep-dependent consolidation of memory, but the specific neural mechanism for this process remains unclear. We show here that cortical spindles are spatiotemporally organized into circular wave-like patterns, organizing neuronal activity over tens of milliseconds, within the timescale for storing memories in large-scale networks across the cortex via spike-time dependent plasticity. These circular patterns repeat over hours of sleep with millisecond temporal precision, allowing reinforcement of the activity patterns through hundreds of reverberations. These results provide a novel mechanistic account for how global sleep oscillations and synaptic plasticity could strengthen networks distributed across the cortex to store coherent and integrated memories. DOI: http://dx.doi.org/10.7554/eLife.17267.001 PMID:27855061

  9. The cognitive cost of sleep lost

    Science.gov (United States)

    McCoy, John G.; Strecker, Robert E.

    2013-01-01

    A substantial body of literature supports the intuitive notion that a good night’s sleep can facilitate human cognitive performance the next day. Deficits in attention, learning & memory, emotional reactivity, and higher-order cognitive processes, such as executive function and decision making, have all been documented following sleep disruption in humans. Thus, whilst numerous clinical and experimental studies link human sleep disturbance to cognitive deficits, attempts to develop valid and reliable rodent models of these phenomena are fewer, and relatively more recent. This review focuses primarily on the cognitive impairments produced by sleep disruption in rodent models of several human patterns of sleep loss/sleep disturbance. Though not an exclusive list, this review will focus on four specific types of sleep disturbance: total sleep deprivation, experimental sleep fragmentation, selective REM sleep deprivation, and chronic sleep restriction. The use of rodent models can provide greater opportunities to understand the neurobiological changes underlying sleep loss induced cognitive impairments. Thus, this review concludes with a description of recent neurobiological findings concerning the neuroplastic changes and putative brain mechanisms that may underlie the cognitive deficits produced by sleep disturbances. PMID:21875679

  10. Sleep Apnea

    Science.gov (United States)

    Sleep apnea is a common disorder that causes your breathing to stop or get very shallow. Breathing ... an hour. The most common type is obstructive sleep apnea. It causes your airway to collapse or ...

  11. Sleep Quiz

    Science.gov (United States)

    ... to ensure that research results lead to health benefits. It works towards this goal by educating health care professionals about sleep disorders and research findings, and translating sleep health ...

  12. A new theoretical approach to the functional meaning of sleep and dreaming in humans based on the maintenance of ‘predictive psychic homeostasis’

    Science.gov (United States)

    Barlow, Peter W.; Baluška, František; Tonin, Paolo; Guescini, Michele; Leo, Giuseppina; Fuxe, Kjell

    2011-01-01

    Different theories have been put forward during the last decade to explain the functional meaning of sleep and dreaming in humans. In the present paper, a new theory is presented which, while taking advantage of these earlier theories, introduces the following new and original aspects:   • Circadian rhythms relevant to various organs of the body affect the reciprocal interactions which operate to maintain constancy of the internal milieu and thereby also affect the sleep/wakefulness cycle. Particular attention is given to the constancy of natraemia and osmolarity and to the permissive role that the evolution of renal function has had for the evolution of the central nervous system and its integrative actions. • The resetting of neuro-endocrine controls at the onset of wakefulness leads to the acquisition of new information and its integration within previously stored memories. This point is dealt with in relation to Moore-Ede’s proposal for the existence of a ’predictive homeostasis’. • The concept of ‘psychic homeostasis’ is introduced and is considered as one of the most important states since it is aimed at the well-being, or eudemonia, of the human psyche. Sleep and dreaming in humans are discussed as important functions for the maintenance of a newly proposed composite state: that of ‘predictive psychic homeostasis’. On the basis of these assumptions, and in accordance with the available neurobiological data, the present paper puts forward the novel hypothesis that sleep and dreaming play important functions in humans by compensating for psychic allostatic overloads. Hence, both consolatory dreams and disturbing nightmares can be part of the vis medicatrix naturae, the natural healing power, in this case, the state of eudemonia. PMID:22448302

  13. A new theoretical approach to the functional meaning of sleep and dreaming in humans based on the maintenance of 'predictive psychic homeostasis'.

    Science.gov (United States)

    Agnati, Luigi F; Barlow, Peter W; Baluška, František; Tonin, Paolo; Guescini, Michele; Leo, Giuseppina; Fuxe, Kjell

    2011-11-01

    Different theories have been put forward during the last decade to explain the functional meaning of sleep and dreaming in humans. In the present paper, a new theory is presented which, while taking advantage of these earlier theories, introduces the following new and original aspects:   • Circadian rhythms relevant to various organs of the body affect the reciprocal interactions which operate to maintain constancy of the internal milieu and thereby also affect the sleep/wakefulness cycle. Particular attention is given to the constancy of natraemia and osmolarity and to the permissive role that the evolution of renal function has had for the evolution of the central nervous system and its integrative actions. • The resetting of neuro-endocrine controls at the onset of wakefulness leads to the acquisition of new information and its integration within previously stored memories. This point is dealt with in relation to Moore-Ede's proposal for the existence of a 'predictive homeostasis'. • The concept of 'psychic homeostasis' is introduced and is considered as one of the most important states since it is aimed at the well-being, or eudemonia, of the human psyche. Sleep and dreaming in humans are discussed as important functions for the maintenance of a newly proposed composite state: that of 'predictive psychic homeostasis'. On the basis of these assumptions, and in accordance with the available neurobiological data, the present paper puts forward the novel hypothesis that sleep and dreaming play important functions in humans by compensating for psychic allostatic overloads. Hence, both consolatory dreams and disturbing nightmares can be part of the vis medicatrix naturae, the natural healing power, in this case, the state of eudemonia.

  14. Sleep and Alertness Management During Military Operations: Questions To Be Answered

    Science.gov (United States)

    2000-03-01

    sleep function. In: C. Stampi (Ed.) Why we nap: evolution, propensity. J Biol Rhythms 1997; 12(6):657-65. chronobiology, and functions of polyphasic ...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO10460 TITLE: Sleep and Alertness Management During Military Operations...Individual Differences in the Adaptability to Irregular Rest-Work Rhythms/Status of the Use of Drugs in Sleep -Wakefulness Management [les Differences entre

  15. An Aß concatemer with altered aggregation propensities

    DEFF Research Database (Denmark)

    Giehm, L; Dal Degan, F; Fraser, P

    2010-01-01

    We present an analysis of the conformational and aggregative properties of an A beta concatemer (Con-Alz) of interest for vaccine development against Alzheimer's disease. Con-Alz consists of 3 copies of the 43 residues of the A beta peptide separated by the P2 and P30 T-cell epitopes from......, but it is unable to assemble into classical amyloid fibrils. Despite its high propensity to aggregate, Con-Alz does not show any significant ability to permeabilize vesicles, which for fibrillating proteins is taken to be a key factor in aggregate cytotoxicity and is attributed to oligomers formed at an early...... stage in the fibrillation process. Physically linking multiple copies of the A beta-peptide may thus sterically restrict Con-Alz against forming cytotoxic oligomers, forcing it instead to adopt a less well-organized assembly of intermeshed polypeptide chains. (C) 2010 Elsevier B.V. All rights reserved....

  16. Probabilities, causes and propensities in physics

    CERN Document Server

    Suárez, Mauricio

    2010-01-01

    This volume defends a novel approach to the philosophy of physics: it is the first book devoted to a comparative study of probability, causality, and propensity, and their various interrelations, within the context of contemporary physics - particularly quantum and statistical physics. The philosophical debates and distinctions are firmly grounded upon examples from actual physics, thus exemplifying a robustly empiricist approach. The essays, by both prominent scholars in the field and promising young researchers, constitute a pioneer effort in bringing out the connections between probabilistic, causal and dispositional aspects of the quantum domain. This book will appeal to specialists in philosophy and foundations of physics, philosophy of science in general, metaphysics, ontology of physics theories, and philosophy of probability.

  17. Spatial predictions of Rhodesian Human African Trypanosomiasis (sleeping sickness prevalence in Kaberamaido and Dokolo, two newly affected districts of Uganda.

    Directory of Open Access Journals (Sweden)

    Nicola A Batchelor

    2009-12-01

    Full Text Available The continued northwards spread of Rhodesian sleeping sickness or Human African Trypanosomiasis (HAT within Uganda is raising concerns of overlap with the Gambian form of the disease. Disease convergence would result in compromised diagnosis and treatment for HAT. Spatial determinants for HAT are poorly understood across small areas. This study examines the relationships between Rhodesian HAT and several environmental, climatic and social factors in two newly affected districts, Kaberamaido and Dokolo. A one-step logistic regression analysis of HAT prevalence and a two-step logistic regression method permitted separate analysis of both HAT occurrence and HAT prevalence. Both the occurrence and prevalence of HAT were negatively correlated with distance to the closest livestock market in all models. The significance of distance to the closest livestock market strongly indicates that HAT may have been introduced to this previously unaffected area via the movement of infected, untreated livestock from endemic areas. This illustrates the importance of the animal reservoir in disease transmission, and highlights the need for trypanosomiasis control in livestock and the stringent implementation of regulations requiring the treatment of cattle prior to sale at livestock markets to prevent any further spread of Rhodesian HAT within Uganda.

  18. Propensity Score Analysis in R: A Software Review

    Science.gov (United States)

    Keller, Bryan; Tipton, Elizabeth

    2016-01-01

    In this article, we review four software packages for implementing propensity score analysis in R: "Matching, MatchIt, PSAgraphics," and "twang." After briefly discussing essential elements for propensity score analysis, we apply each package to a data set from the Early Childhood Longitudinal Study in order to estimate the…

  19. Advanced Issues in Propensity Scores: Longitudinal and Missing Data

    Science.gov (United States)

    Kupzyk, Kevin A.; Beal, Sarah J.

    2017-01-01

    In order to investigate causality in situations where random assignment is not possible, propensity scores can be used in regression adjustment, stratification, inverse-probability treatment weighting, or matching. The basic concepts behind propensity scores have been extensively described. When data are longitudinal or missing, the estimation and…

  20. Sleep, Neuronal Plasticity and Brain Function

    NARCIS (Netherlands)

    Meerlo, Peter; Benca, Ruth M.; Abel, Ted

    2015-01-01

    Sleep is truly one of the biggest mysteries in behavioral neuroscience. Humans spend a substantial portion of their lives asleep, as do all other mammalian and bird species that have been studied to date, yet the functions of sleep remain elusive and continue to be a topic of debate among sleep

  1. Tryptophan-enriched cereal intake improves nocturnal sleep, melatonin, serotonin, and total antioxidant capacity levels and mood in elderly humans.

    Science.gov (United States)

    Bravo, R; Matito, S; Cubero, J; Paredes, S D; Franco, L; Rivero, M; Rodríguez, A B; Barriga, C

    2013-08-01

    Melatonin and serotonin rhythms, which exhibit a close association with the endogenous circadian component of sleep, are attenuated with increasing age. This decrease seems to be linked to sleep alterations in the elderly. Chrononutrition is a field of chronobiology that establishes the principle of consuming foodstuffs at times of the day when they are more useful for health, improving, therefore, biorhythms and physical performance. Our aim was to analyze whether the consumption of cereals enriched with tryptophan, the precursor of both serotonin and melatonin, may help in the reconsolidation of the sleep/wake cycle and counteract depression and anxiety in 35 middle-aged/elderly (aged 55-75 year) volunteers in a simple blind assay. Data were collected for 3 weeks according to the following schedule: The control week participants consumed standard cereals (22.5 mg tryptophan in 30 g cereals per dose) at breakfast and dinner; for the treatment week, cereals enriched with a higher dose of tryptophan (60 mg tryptophan in 30 g cereals per dose) were eaten at both breakfast and dinner; the posttreatment week volunteers consumed their usual diet. Each participant wore a wrist actimeter that logged activity during the whole experiment. Urine was collected to analyze melatonin and serotonin urinary metabolites and to measure total antioxidant capacity. The consumption of cereals containing the higher dose in tryptophan increased sleep efficiency, actual sleep time, immobile time, and decreased total nocturnal activity, sleep fragmentation index, and sleep latency. Urinary 6-sulfatoxymelatonin, 5-hydroxyindoleacetic acid levels, and urinary total antioxidant capacity also increased respectively after tryptophan-enriched cereal ingestion as well as improving anxiety and depression symptoms. Cereals enriched with tryptophan may be useful as a chrononutrition tool for alterations in the sleep/wake cycle due to age.

  2. A review of the effects of hypoxia, sleep deprivation and transcranial magnetic stimulation on EEG activity in humans: challenges for drug discovery for Alzheimer's disease.

    Science.gov (United States)

    Babiloni, Claudio; Del Percio, Claudio; Lizio, Roberta; Infarinato, Francesco; Blin, Olivier; Bartres-Faz, David; Dix, Sophie L; Bentivoglio, Marina; Soricelli, Andrea; Bordet, Regis; Rossini, Paolo M; Richardson, Jill C

    2014-01-01

    Different kinds of challenge can alter cognitive process and electroencephalographic (EEG) rhythms in humans. This can provide an alternative paradigms to evaluate treatment effects in drug discovery. Here, we report recent findings on the effects of challenges represented by sleep deprivation (SD), transient hypoxia, and transcranial magnetic stimulation (TMS) in healthy volunteers on cognitive processes and EEG rhythms to build a knowledge platform for novel research for drug discovery in AD Alzheimer's disease (AD). Sleep pressure enhanced frontal delta rhythms (EEG rhythms typically recorded in AD patients. However, the relationship between the cognitive and EEG effects of such challenges is poorly understood. TMS reversibly interfered with higher brain functions during EEG recordings, but few studies have investigated the relationship between the cognitive and EEG effects of TMS. In conclusion, SD is the most mature challenge model for testing new drugs for AD. Future investigation is needed to better understand the opportunities offered by TMS and hypoxia challenges.

  3. Analysis of the effects of non-supine sleeping positions on the stress, strain, deformation and intraocular pressure of the human eye

    Science.gov (United States)

    Volpe, Peter A.

    This thesis presents analytical models, finite element models and experimental data to investigate the response of the human eye to loads that can be experienced when in a non-supine sleeping position. The hypothesis being investigated is that non-supine sleeping positions can lead to stress, strain and deformation of the eye as well as changes in intraocular pressure (IOP) that may exacerbate vision loss in individuals who have glaucoma. To investigate the quasi-static changes in stress and internal pressure, a Fluid-Structure Interaction simulation was performed on an axisymmetrical model of an eye. Common Aerospace Engineering methods for analyzing pressure vessels and hyperelastic structural walls are applied to developing a suitable model. The quasi-static pressure increase was used in an iterative code to analyze changes in IOP over time.

  4. Sleep, Torpor and Memory Impairment

    Science.gov (United States)

    Palchykova, S.; Tobler, I.

    It is now well known that daily torpor induces a sleep deficit. Djungarian hamsters emerging from this hypometabolic state spend most of the time in sleep. This sleep is characterized by high initial values of EEG slow-wave activity (SWA) that monotonically decline during recovery sleep. These features resemble the changes seen in numerous species during recovery after prolonged wakefulness or sleep deprivation (SD). When hamsters are totally or partially sleep deprived immediately after emerging from torpor, an additional increase in SWA can be induced. It has been therefore postulated, that these slow- waves are homeostatically regulated, as predicted by the two-process model of sleep regulation, and that during daily torpor a sleep deficit is accumulated as it is during prolonged waking. The predominance of SWA in the frontal EEG observed both after SD and daily torpor provides further evidence for the similarity of these conditions. It has been shown in several animal and human studies that sleep can enhance memory consolidation, and that SD leads to memory impairment. Preliminary data obtained in the Djungarian hamster showed that both SD and daily torpor result in object recognition deficits. Thus, animals subjected to SD immediately after learning, or if they underwent an episode of daily torpor between learning and retention, displayed impaired recognition memory for complex object scenes. The investigation of daily torpor can reveal mechanisms that could have important implications for hypometabolic state induction in other mammalian species, including humans.

  5. Effects of cognitive behavioral therapy in patients with depressive disorder and comorbid insomnia: A propensity score-matched outcome study.

    Science.gov (United States)

    Hsu, Hui-Min; Chou, Kuei-Ru; Lin, Kuan-Chia; Chen, Kuan-Yu; Su, Shu-Fang; Chung, Min-Huey

    2015-10-01

    We evaluated the effects of cognitive behavioral therapy for insomnia (CBT-I) in inpatients with a diagnosis of depression and comorbid insomnia. This study used a prospective, parallel-group design. The experimental group received CBT-I for no more than 90 min once weekly for 6 weeks and the control group only have health education manuals for insomnia. The following questionnaires were administered at baseline: the Hamilton Rating Scale for Depression (HAM-D), Dysfunctional Beliefs and Attitudes about Sleep (DBAS), Presleep Arousal Scale (PSAS), Sleep Hygiene Practice (SHP), and Pittsburgh Sleep Quality Index. The questionnaires were readministered after the completion of the 6-wk CBT-I intervention and 1 month following the completion of CBT-I, to determine the effects of the CBT-I intervention over time. The analysis of Generalized Estimation Equations was identified the difference between the experimental group and the control group by controlling for the variables in BZD dose and propensity score of gender, age, and the scores for the DBAS-16, PSAS, SHPS, and HAM-D. Consequently, the significant difference in the PSQI scores was observed at the 1-month follow-up assessment however, no significant intergroup difference in the PSQI scores was found at the completion of the CBT-I intervention between two groups. As a conclusion, we found that overall sleep quality significantly improved in patients who received CBT-I after we controlled for the BZD dose and propensity score, which suggests that CBT-I may represent a useful clinical strategy for improving sleep quality in patients with depression and comorbid insomnia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Voluntary Sleep Loss in Rats

    Science.gov (United States)

    Oonk, Marcella; Krueger, James M.; Davis, Christopher J.

    2016-01-01

    Study Objectives: Animal sleep deprivation (SDEP), in contrast to human SDEP, is involuntary and involves repeated exposure to aversive stimuli including the inability of the animal to control the waking stimulus. Therefore, we explored intracranial self-stimulation (ICSS), an operant behavior, as a method for voluntary SDEP in rodents. Methods: Male Sprague-Dawley rats were implanted with electroencephalography/electromyography (EEG/EMG) recording electrodes and a unilateral bipolar electrode into the lateral hypothalamus. Rats were allowed to self-stimulate, or underwent gentle handling-induced SDEP (GH-SDEP), during the first 6 h of the light phase, after which they were allowed to sleep. Other rats performed the 6 h ICSS and 1 w later were subjected to 6 h of noncontingent stimulation (NCS). During NCS the individual stimulation patterns recorded during ICSS were replayed. Results: After GH-SDEP, ICSS, or NCS, time in nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep increased. Further, in the 24 h after SDEP, rats recovered all of the REM sleep lost during SDEP, but only 75% to 80% of the NREM sleep lost, regardless of the SDEP method. The magnitude of EEG slow wave responses occurring during NREM sleep also increased after SDEP treatments. However, NREM sleep EEG slow wave activity (SWA) responses were attenuated following ICSS, compared to GH-SDEP and NCS. Conclusions: We conclude that ICSS and NCS can be used to sleep deprive rats. Changes in rebound NREM sleep EEG SWA occurring after ICSS, NCS, and GH-SDEP suggest that nonspecific effects of the SDEP procedure differentially affect recovery sleep phenotypes. Citation: Oonk M, Krueger JM, Davis CJ. Voluntary sleep loss in rats. SLEEP 2016;39(7):1467–1479. PMID:27166236

  7. Cutaneous warming promotes sleep onset.

    Science.gov (United States)

    Raymann, Roy J E M; Swaab, Dick F; Van Someren, Eus J W

    2005-06-01

    Sleep occurs in close relation to changes in body temperature. Both the monophasic sleep period in humans and the polyphasic sleep periods in rodents tend to be initiated when core body temperature is declining. This decline is mainly due to an increase in skin blood flow and consequently skin warming and heat loss. We have proposed that these intrinsically occurring changes in core and skin temperatures could modulate neuronal activity in sleep-regulating brain areas (Van Someren EJW, Chronobiol Int 17: 313-54, 2000). We here provide results compatible with this hypothesis. We obtained 144 sleep-onset latencies while directly manipulating core and skin temperatures within the comfortable range in eight healthy subjects under controlled conditions. The induction of a proximal skin temperature difference of only 0.78 +/- 0.03 degrees C (mean +/- SE) around a mean of 35.13 +/- 0.11 degrees C changed sleep-onset latency by 26%, i.e., by 3.09 minutes [95% confidence interval (CI), 1.91 to 4.28] around a mean of 11.85 min (CI, 9.74 to 14.41), with faster sleep onsets when the proximal skin was warmed. The reduction in sleep-onset latency occurred despite a small but significant decrease in subjective comfort during proximal skin warming. The induction of changes in core temperature (delta = 0.20 +/- 0.02 degrees C) and distal skin temperature (delta = 0.74 +/- 0.05 degrees C) were ineffective. Previous studies have demonstrated correlations between skin temperature and sleep-onset latency. Also, sleep disruption by ambient temperatures that activate thermoregulatory defense mechanisms has been shown. The present study is the first to experimentally demonstrate a causal contribution to sleep-onset latency of skin temperature manipulations within the normal nocturnal fluctuation range. Circadian and sleep-appetitive behavior-induced variations in skin temperature might act as an input signal to sleep-regulating systems.

  8. Sleep-Dependent Modulation of Metabolic Rate in Drosophila.

    Science.gov (United States)

    Stahl, Bethany A; Slocumb, Melissa E; Chaitin, Hersh; DiAngelo, Justin R; Keene, Alex C

    2017-08-01

    Dysregulation of sleep is associated with metabolic diseases, and metabolic rate (MR) is acutely regulated by sleep-wake behavior. In humans and rodent models, sleep loss is associated with obesity, reduced metabolic rate, and negative energy balance, yet little is known about the neural mechanisms governing interactions between sleep and metabolism. We have developed a system to simultaneously measure sleep and MR in individual Drosophila, allowing for interrogation of neural systems governing interactions between sleep and metabolic rate. Like mammals, MR in flies is reduced during sleep and increased during sleep deprivation suggesting sleep-dependent regulation of MR is conserved across phyla. The reduction of MR during sleep is not simply a consequence of inactivity because MR is reduced ~30 minutes following the onset of sleep, raising the possibility that CO2 production provides a metric to distinguish different sleep states in the fruit fly. To examine the relationship between sleep and metabolism, we determined basal and sleep-dependent changes in MR is reduced in starved flies, suggesting that starvation inhibits normal sleep-associated effects on metabolic rate. Further, translin mutant flies that fail to suppress sleep during starvation demonstrate a lower basal metabolic rate, but this rate was further reduced in response to starvation, revealing that regulation of starvation-induced changes in MR and sleep duration are genetically distinct. Therefore, this system provides the unique ability to simultaneously measure sleep and oxidative metabolism, providing novel insight into the physiological changes associated with sleep and wakefulness in the fruit fly.

  9. Sleep education during pregnancy for new mothers

    Directory of Open Access Journals (Sweden)

    Kempler Liora

    2012-12-01

    Full Text Available Abstract Background There is a high association between disturbed (poor quality sleep and depression, which has lead to a consensus that there is a bidirectional relationship between sleep and mood. One time in a woman’s life when sleep is commonly disturbed is during pregnancy and following childbirth. It has been suggested that sleep disturbance is another factor that may contribute to the propensity for women to become depressed in the postpartum period compared to other periods in their life. Post Natal Depression (PND is common (15.5% and associated with sleep disturbance, however, no studies have attempted to provide a sleep-focused intervention to pregnant women and assess whether this can improve sleep, and consequently maternal mood post-partum. The primary aim of this research is to determine the efficacy of a brief psychoeducational sleep intervention compared with a control group to improve sleep management, with a view to reduce depressive symptoms in first time mothers. Method This randomised controlled trial will recruit 214 first time mothers during the last trimester of their pregnancy. Participants will be randomised to receive either a set of booklets (control group or a 3hour psychoeducational intervention that focuses on sleep. The primary outcomes of this study are sleep-related, that is sleep quality and sleepiness for ten months following the birth of the baby. The secondary outcome is depressive symptoms. It is hypothesised that participants in the intervention group will have better sleep quality and sleepiness in the postpartum period than women in the control condition. Further, we predict that women who receive the sleep intervention will have lower depression scores postpartum compared with the control group. Discussion This study aims to provide an intervention that will improve maternal sleep in the postpartum period. If sleep can be effectively improved through a brief psychoeducational program, then it may

  10. Central sleep apnea

    Science.gov (United States)

    Sleep apnea - central; Obesity - central sleep apnea; Cheyne-Stokes - central sleep apnea; Heart failure - central sleep apnea ... Central sleep apnea results when the brain temporarily stops sending signals to the muscles that control breathing. The condition ...

  11. Sleep disorders - overview

    Science.gov (United States)

    Insomnia; Narcolepsy; Hypersomina; Daytime sleepiness; Sleep rhythm; Sleep disruptive behaviors; Jet lag ... excessive daytime sleepiness) Problems sticking to a regular sleep schedule (sleep rhythm problem) Unusual behaviors during sleep ( ...

  12. Effect of SCN lesions on sleep in squirrel monkeys: evidence for opponent processes in sleep-wake regulation.

    Science.gov (United States)

    Edgar, D M; Dement, W C; Fuller, C A

    1993-03-01

    Sleep and wakefulness are governed by both the suprachiasmatic nuclei of the hypothalamus (SCN), and a sleep homeostatic process; however, the interaction of these control systems is not well understood. From rodent studies it has been assumed that the SCN promote neither wake nor sleep but gate the homeostatic sleep-promoting process. Yet in humans sleep tendency is lowest during the later waking hours of the day, and sleep duration can be predicted because of the precise circadian timing of waking. Thus in primates, the SCN could assure sleep-wake cycle consolidation by actively promoting or facilitating wakefulness. To evaluate this hypothesis, we examined the sleep-wake and sleep-stage patterns of intact and SCN-lesioned (SCNx) squirrel monkeys maintained in constant light. This diurnal primate has consolidated sleep and wake patterns more similar to man than rodents. Sleep-wake, sleep stages, brain temperature, and drinking circadian rhythms were eliminated, and total sleep time was significantly increased (4.0 hr, P sleep) and REM sleep were not significantly affected by SCN lesions. Increased total sleep time was associated with a reduction in subjective day wake consolidation, as evidenced by substantially shorter wake bout lengths in SCNx monkeys (15 +/- 6 min) as compared to intact monkeys (223 +/- 10 min; P sleep times, and implicate an alternative sleep-wake regulatory model in which an SCN-dependent process actively facilitates the initiation and maintenance of wakefulness and opposes homeostatic sleep tendency during the subjective day in diurnal primates.

  13. The NLRP3 inflammasome modulates sleep and NREM sleep delta power induced by spontaneous wakefulness, sleep deprivation and lipopolysaccharide.

    Science.gov (United States)

    Zielinski, Mark R; Gerashchenko, Dmitry; Karpova, Svetlana A; Konanki, Varun; McCarley, Robert W; Sutterwala, Fayyaz S; Strecker, Robert E; Basheer, Radhika

    2017-05-01

    Both sleep loss and pathogens can enhance brain inflammation, sleep, and sleep intensity as indicated by electroencephalogram delta (δ) power. The pro-inflammatory cytokine interleukin-1 beta (IL-1β) is increased in the cortex after sleep deprivation (SD) and in response to the Gram-negative bacterial cell-wall component lipopolysaccharide (LPS), although the exact mechanisms governing these effects are unknown. The nucleotide-binding domain and leucine-rich repeat protein-3 (NLRP3) inflammasome protein complex forms in response to changes in the local environment and, in turn, activates caspase-1 to convert IL-1β into its active form. SD enhances the cortical expression of the somnogenic cytokine IL-1β, although the underlying mechanism is, as yet, unidentified. Using NLRP3-gene knockout (KO) mice, we provide evidence that NLRP3 inflammasome activation is a crucial mechanism for the downstream pathway leading to increased IL-1β-enhanced sleep. NLRP3 KO mice exhibited reduced non-rapid eye movement (NREM) sleep during the light period. We also found that sleep amount and intensity (δ activity) were drastically attenuated in NLRP3 KO mice following SD (homeostatic sleep response), as well as after LPS administration, although they were enhanced by central administration of IL-1β. NLRP3, ASC, and IL1β mRNA, IL-1β protein, and caspase-1 activity were greater in the somatosensory cortex at the end of the wake-active period when sleep propensity was high and after SD in wild-type but not NLRP3 KO mice. Thus, our novel and converging findings suggest that the activation of the NLRP3 inflammasome can modulate sleep induced by both increased wakefulness and a bacterial component in the brain. Published by Elsevier Inc.

  14. A literature review of economic evaluations for a neglected tropical disease: human African trypanosomiasis ("sleeping sickness").

    Science.gov (United States)

    Sutherland, C Simone; Yukich, Joshua; Goeree, Ron; Tediosi, Fabrizio

    2015-02-01

    Human African trypanosomiasis (HAT) is a disease caused by infection with the parasite Trypanosoma brucei gambiense or T. b. rhodesiense. It is transmitted to humans via the tsetse fly. Approximately 70 million people worldwide were at risk of infection in 1995, and approximately 20,000 people across Africa are infected with HAT. The objective of this review was to identify existing economic evaluations in order to summarise cost-effective interventions to reduce, control, or eliminate the burden of HAT. The studies included in the review were compared and critically appraised in order to determine if there were existing standardised methods that could be used for economic evaluation of HAT interventions or if innovative methodological approaches are warranted. A search strategy was developed using keywords and was implemented in January 2014 in several databases. The search returned a total of 2,283 articles. After two levels of screening, a total of seven economic evaluations were included and underwent critical appraisal using the Scottish Intercollegiate Guidelines Network (SIGN) Methodology Checklist 6: Economic Evaluations. Results from the existing studies focused on the cost-effectiveness of interventions for the control and reduction of disease transmission. Modelling was a common method to forecast long-term results, and publications focused on interventions by category, such as case detection, diagnostics, drug treatments, and vector control. Most interventions were considered cost-effective based on the thresholds described; however, the current treatment, nifurtomix-eflornithine combination therapy (NECT), has not been evaluated for cost-effectiveness, and considerations for cost-effective strategies for elimination have yet to be completed. Overall, the current evidence highlights the main components that play a role in control; however, economic evaluations of HAT elimination strategies are needed to assist national decision makers, stakeholders, and

  15. It's practice, with sleep, that makes perfect: implications of sleep-dependent learning and plasticity for skill performance.

    Science.gov (United States)

    Walker, Matthew P; Stickgold, Robert

    2005-04-01

    Although there is no consensus regarding the functions of sleep, one exciting hypothesis is that sleep contributes importantly to learning and memory. Over the last decade, several studies have provided substantive evidence supporting the role of sleep in memory processing. This article focuses on sleep-dependent learning and brain plasticity in humans, specifically in the development of skill performance that is the foundation of many sports actions. The different forms and stages of human memory are discussed, then evidence of sleep-dependent skill learning and associated sleep-dependent brain plasticity is described. In conclusion, a consideration of the fundamental importance of sleep in real-life skill learning is provided.

  16. Chronic head-down-tilt sleeping as physiological regulator of bone remodelling during diminished muscular activity in humans.

    Science.gov (United States)

    Kakuris, Kostas K; Yaroshenko, Yuri N; Charapakhin, Kirill P; Neofitov, Nikolay H

    2017-07-01

    Head-down-tilt (HDT) sleeping with periodic fluid redistribution (PFR) assumes a significant importance by the possibility of regulating bone remodelling. We hypothesized that HDT sleeping with chronic PFR which expands fluid volume would contribute to and/or increase bone formation. Therefore, we studied the potential benefits of osteogenesis with HDT sleeping of chronic PFR during diminished muscular activity (hypokinesia; HK). Studies were conducted on 40 male healthy volunteers. They were divided into four groups: head-down-tilt sleeping control subjects (HDTSCS), head-down-tilt sleeping hypokinetic subjects (HDTSHS), active control subjects (ACS) and hypokinetic subjects (HKS). The iliac crest cancellous bone and trabecular bone volume and cortical thickness were measured during pre-experimental period of 390 days and experimental period of 360 days. Iliac crest cancellous bone and trabecular bone volume and cortical thickness were increased (Psleeping with PFR on increases formation of bone demonstrating osteogenesis of bone during diminished muscular activity. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  17. NREM Sleep Stage Transitions Control Ultradian REM Sleep Rhythm

    Science.gov (United States)

    Kishi, Akifumi; Yasuda, Hideaki; Matsumoto, Takahisa; Inami, Yasushi; Horiguchi, Jun; Tamaki, Masako; Struzik, Zbigniew R.; Yamamoto, Yoshiharu

    2011-01-01

    Study Objectives: The cyclic sequence of NREM and REM sleep, the so-called ultradian rhythm, is a highly characteristic feature of sleep. However, the mechanisms responsible for the ultradian REM sleep rhythm, particularly in humans, have not to date been fully elucidated. We hypothesize that a stage transition mechanism is involved in the determination of the ultradian REM sleep rhythm. Participants: Ten healthy young male volunteers (age: 22 ± 4 years, range 19–31 years) spent 3 nights in a sleep laboratory. The first was the adaptation night, and the second was the baseline night. On the third night, the subjects received risperidone (1 mg tablet), a central serotonergic and dopaminergic antagonist, 30 min before the polysomnography recording. Measurements and Results: We measured and investigated transition probabilities between waking, REM, and NREM sleep stages (N1, N2, and N3) within the REM-onset intervals, defined as the intervals between the onset of one REM period and the beginning of the next, altered by risperidone. We also calculated the transition intensity (i.e., instantaneous transition rate) and examined the temporal pattern of transitions within the altered REM-onset intervals. We found that when the REM-onset interval was prolonged by risperidone, the probability of transitions from N2 to N3 was significantly increased within the same prolonged interval, with a significant delay and/or recurrences of the peak intensity of transitions from N2 to N3. Conclusions: These results suggest that the mechanism governing NREM sleep stage transitions (from light to deep sleep) plays an important role in determining ultradian REM sleep rhythms. Citation: Kishi A; Yasuda H; Matsumoto T; Inami Y; Horiguchi J; Tamaki M; Struzik ZR; Yamamoto Y. NREM sleep stage transitions control ultradian REM sleep rhythm. SLEEP 2011;34(10):1423-1432. PMID:21966074

  18. Nightmare frequency is related to a propensity for mirror behaviors.

    Science.gov (United States)

    Nielsen, Tore; Powell, Russell A; Kuiken, Don

    2013-12-01

    We previously reported that college students who indicated engaging in frequent dream-enacting behaviors also scored high on a new measure of mirror behaviors, which is the propensity to imitate another person's emotions or actions. Since dream-enacting behaviors are frequently the culmination of nightmares, one explanation for the observed relationship is that individuals who frequently display mirror behaviors are also prone to nightmares. We used the Mirror Behavior Questionnaire (MBQ) and self-reported frequencies of nightmares to assess this possibility. A sample of 480 students, consisting of 188 males (19.2±1.73 years) and 292 females (19.0±1.55 years) enrolled in a first-year university psychology course, participated for course credit. They completed a battery of questionnaires that included the 16-item MBQ, plus an item about nightmare frequency (NMF) in the past 30 days. NMF scores were split to create low, medium, and high NMF groups. MBQ total scores were significantly higher for female than for male subjects, but an interaction revealed that this was true only for Hi-NMF subjects. MBQ Factor 4, Motor Skill Imitation, paralleled this global interaction for females, whereas MBQ Factor 3, Sleepiness/Anger Contagion, was elevated only for Hi-NMF males. Item analyses indicated that Hi- and Med-NMF females scored higher than Lo-NMF females on the 3 items of Factor 4 that reflect voluntary imitation (imitating famous/cartoon voices, being a physically active spectator, and learning new skills by observing), as well as on 2 other items that reflect involuntary imitation (contagious yawning and self-rated empathy). Although Hi- and Lo-NMF males differed most clearly on the sleepiness item of Factor 3, all 3 items on this factor (including anger contagion and contagious yawning) are plausibly associated with perception of and response to social threat. Results provide evidence that among females nightmares are associated with voluntary and involuntary mirror

  19. Sleep-wake cycle effects on sleep stages, and plasma cortisol and growth secretions

    Science.gov (United States)

    1971-01-01

    Studies were made of the effects of various stimuli on sleep stages and of secretion of a number of different hormones during sleep in human subjects. Among the stimuli were vestibular stimulation, the action of L-Dopa, and a three-hour sleep-wake cycle. Hormones observed included plasma cortisol, growth hormone, dehydroisoandrosterone, and luteinizing hormone. Relationships between sleep onset, the presence of Cushing's syndrome or sleep disorders, and ultradian rhythmicity, and hormone secretion were investigated. Sleep patterns and hormone secretion in normal subjects were also studied.

  20. Functional neuroimaging insights into how sleep and sleep deprivation affect memory and cognition.

    Science.gov (United States)

    Chee, Michael W L; Chuah, Lisa Y M

    2008-08-01

    The review summarizes current knowledge about what fMRI has revealed regarding the neurobehavioral correlates of sleep deprivation and sleep-dependent memory consolidation. Functional imaging studies of sleep deprivation have characterized its effects on a number of cognitive domains, the best studied of these being working memory. There is a growing appreciation that it is important to consider interindividual differences in vulnerability to sleep deprivation, task and task difficulty when interpreting imaging results. Our understanding of the role of sleep and the dynamic evolution of offline memory consolidation has benefited greatly from human imaging studies. Both hippocampal-dependent and hippocampal-independent memory systems have been studied. Functional imaging studies contrasting sleep-deprived and well-rested brains provide substantial evidence that sleep is highly important for optimal cognitive function and learning. The experimental paradigms developed to date merit evaluation in clinical settings to determine the impact of sleep disruption in sleep disorders.

  1. Effects of sleep deprivation on prospective memory.

    Science.gov (United States)

    Grundgeiger, Tobias; Bayen, Ute J; Horn, Sebastian S

    2014-01-01

    Sleep deprivation reduces cognitive performance; however, its effects on prospective memory (remembering to perform intended actions) are unknown. One view suggests that effects of sleep deprivation are limited to tasks associated with prefrontal functioning. An alternative view suggests a global, unspecific effect on human cognition, which should affect a variety of cognitive tasks. We investigated the impact of sleep deprivation (25 hours of sleep deprivation vs. no sleep deprivation) on prospective-memory performance in more resource-demanding and less resource-demanding prospective-memory tasks. Performance was lower after sleep deprivation and with a more resource-demanding prospective-memory task, but these factors did not interact. These results support the view that sleep deprivation affects cognition more globally and demonstrate that sleep deprivation increases failures to carry out intended actions, which may have severe consequences in safety-critical situations.

  2. Voluntary Sleep Loss in Rats.

    Science.gov (United States)

    Oonk, Marcella; Krueger, James M; Davis, Christopher J

    2016-07-01

    Animal sleep deprivation (SDEP), in contrast to human SDEP, is involuntary and involves repeated exposure to aversive stimuli including the inability of the animal to control the waking stimulus. Therefore, we explored intracranial self-stimulation (ICSS), an operant behavior, as a method for voluntary SDEP in rodents. Male Sprague-Dawley rats were implanted with electroencephalography/electromyography (EEG/EMG) recording electrodes and a unilateral bipolar electrode into the lateral hypothalamus. Rats were allowed to self-stimulate, or underwent gentle handling-induced SDEP (GH-SDEP), during the first 6 h of the light phase, after which they were allowed to sleep. Other rats performed the 6 h ICSS and 1 w later were subjected to 6 h of noncontingent stimulation (NCS). During NCS the individual stimulation patterns recorded during ICSS were replayed. After GH-SDEP, ICSS, or NCS, time in nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep increased. Further, in the 24 h after SDEP, rats recovered all of the REM sleep lost during SDEP, but only 75% to 80% of the NREM sleep lost, regardless of the SDEP method. The magnitude of EEG slow wave responses occurring during NREM sleep also increased after SDEP treatments. However, NREM sleep EEG slow wave activity (SWA) responses were attenuated following ICSS, compared to GH-SDEP and NCS. We conclude that ICSS and NCS can be used to sleep deprive rats. Changes in rebound NREM sleep EEG SWA occurring after ICSS, NCS, and GH-SDEP suggest that nonspecific effects of the SDEP procedure differentially affect recovery sleep phenotypes. © 2016 Associated Professional Sleep Societies, LLC.

  3. Nap sleep spindle correlates of intelligence.

    Science.gov (United States)

    Ujma, Péter P; Bódizs, Róbert; Gombos, Ferenc; Stintzing, Johannes; Konrad, Boris N; Genzel, Lisa; Steiger, Axel; Dresler, Martin

    2015-11-26

    Sleep spindles are thalamocortical oscillations in non-rapid eye movement (NREM) sleep, that play an important role in sleep-related neuroplasticity and offline information processing. Several studies with full-night sleep recordings have reported a positive association between sleep spindles and fluid intelligence scores, however more recently it has been shown that only few sleep spindle measures correlate with intelligence in females, and none in males. Sleep spindle regulation underlies a circadian rhythm, however the association between spindles and intelligence has not been investigated in daytime nap sleep so far. In a sample of 86 healthy male human subjects, we investigated the correlation between fluid intelligence and sleep spindle parameters in an afternoon nap of 100 minutes. Mean sleep spindle length, amplitude and density were computed for each subject and for each derivation for both slow and fast spindles. A positive association was found between intelligence and slow spindle duration, but not any other sleep spindle parameter. As a positive correlation between intelligence and slow sleep spindle duration in full-night polysomnography has only been reported in females but not males, our results suggest that the association between intelligence and sleep spindles is more complex than previously assumed.

  4. Sleep-related deglutition in children.

    Science.gov (United States)

    Sato, Kiminori; Nakashima, Tadashi

    2007-10-01

    Clearance of the pharynx by deglutition is important in protecting the airway. The pattern of deglutition during sleep was investigated in children. Ten normal human children (8.6 +/- 2.9 years) were examined via time-matched recordings of polysomnography and of surface electromyography (EMG) of the thyrohyoid and suprahyoid muscles. During sleep, deglutition was episodic, and it was absent for long periods. The mean number of swallows per hour (+/- SD) during the total sleep time was 2.8 +/- 1.7 per hour. The mean period of the longest absence of deglutition was 59.7 +/- 20.3 minutes. Most deglutition occurred in association with spontaneous electroencephalographic arousal in rapid eye movement (REM) and non-REM sleep. Deglutition was related to sleep stage. The mean number of swallows per hour was 27.4 +/- 27.4 during stage 1 sleep, 3.1 +/- 3.5 during stage 2 sleep, 2.8 +/- 3.3 during stage 3 sleep, and 0.9 +/- 0.8 during stage 4 sleep. The deeper the sleep stage became, the lower the mean deglutition frequency became. The mean number of swallows per hour was 2.2 +/- 2.1 during REM sleep. The EMG amplitude dropped to the lowest level of recording during REM sleep. Deglutition, a vital function, is infrequent during sleep in children.

  5. Neurobiological linkage between stress and sleep

    Science.gov (United States)

    Sanford, Larry D.; Wellman, Laurie L.

    2012-10-01

    Stress can have a significant negative impact on health and stress-induced alterations in sleep are implicated in both human sleep disorders and in psychiatric disorders in which sleep is affected. We have demonstrated that the amygdala, a region critical for regulating emotion, is a key modulator of sleep. Our current research is focused on understanding how the amygdala and stressful emotion affect sleep and on the role sleep plays in recovery from stress. We have implemented animal models to examine the how stress and stress-related memories impact sleep. Experiencing uncontrollable stress and reminders of uncontrollable stress can produce significant reductions in sleep, in particular rapid eye movement sleep. We are using these models to explore the neurobiology linking stress-related emotion and sleep. This research is relevant for sleep disorders such as insomnia and into mental disorders in which sleep is affected such as post-traumatic stress disorder (PTSD), which is typically characterized by a prominent sleep disturbance in the aftermath of exposure to a psychologically traumatic event.

  6. Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation

    Science.gov (United States)

    Irwin, Michael R.; Olmstead, Richard; Carroll, Judith E.

    2015-01-01

    Background Sleep disturbance is associated with inflammatory disease risk and all-cause mortality. Here, we assess global evidence linking sleep disturbance, sleep duration, and inflammation in adult humans. Methods A systematic search of English language publications was performed, with inclusion of primary research articles that characterized sleep disturbance and/or sleep duration or performed experimental sleep deprivation, and assessed inflammation by levels of circulating markers. Effect sizes (ES) and 95% confidence intervals (CI) were extracted and pooled using a random effect model. Results A total of 72 studies (n>50000) were analyzed with assessment of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor α (TNF). Sleep disturbance was associated with higher levels of CRP (ES 0.12; 95% CI 0.05 – 0.19) and IL-6 (ES 0.20; 95% CI 0.08 – 0.31). Shorter sleep duration, but not the extreme of short sleep, was associated with higher levels of CRP (ES 0.09; 95% CI 0.01 – 0.17) but not IL-6 (ES 0.03; 95% CI −0.09 – 0.14). The extreme of long sleep duration was associated with higher levels of CRP (ES 0.17; 95% CI 0.01 – 0.34) and IL-6 (ES 0.11; 95% CI 0.02 – 0.20). Neither sleep disturbances nor sleep duration was associated with TNF. Neither experimental sleep deprivation nor sleep restriction was associated with CRP, IL-6, or TNF. Some heterogeneity among studies was found, but no evidence of publication bias. Conclusions Sleep disturbance and long sleep duration, but not short sleep duration, are associated with increases in markers of systemic inflammation. PMID:26140821

  7. Sleep Disturbance, Sleep Duration, and Inflammation: A Systematic Review and Meta-Analysis of Cohort Studies and Experimental Sleep Deprivation.

    Science.gov (United States)

    Irwin, Michael R; Olmstead, Richard; Carroll, Judith E

    2016-07-01

    Sleep disturbance is associated with inflammatory disease risk and all-cause mortality. Here, we assess global evidence linking sleep disturbance, sleep duration, and inflammation in adult humans. A systematic search of English language publications was performed, with inclusion of primary research articles that characterized sleep disturbance and/or sleep duration or performed experimental sleep deprivation and assessed inflammation by levels of circulating markers. Effect sizes (ES) and 95% confidence intervals (CI) were extracted and pooled using a random effect model. A total of 72 studies (n > 50,000) were analyzed with assessment of C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor α (TNFα). Sleep disturbance was associated with higher levels of CRP (ES .12; 95% CI = .05-.19) and IL-6 (ES .20; 95% CI = .08-.31). Shorter sleep duration, but not the extreme of short sleep, was associated with higher levels of CRP (ES .09; 95% CI = .01-.17) but not IL-6 (ES .03; 95% CI: -.09 to .14). The extreme of long sleep duration was associated with higher levels of CRP (ES .17; 95% CI = .01-.34) and IL-6 (ES .11; 95% CI = .02-20). Neither sleep disturbances nor sleep duration was associated with TNFα. Neither experimental sleep deprivation nor sleep restriction was associated with CRP, IL-6, or TNFα. Some heterogeneity among studies was found, but there was no evidence of publication bias. Sleep disturbance and long sleep duration, but not short sleep duration, are associated with increases in markers of systemic inflammation. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  8. The validity, reliability, and utility of the iButton® for measurement of body temperature circadian rhythms in sleep/wake research.

    Science.gov (United States)

    Hasselberg, Michael J; McMahon, James; Parker, Kathy

    2013-01-01

    Changes in core body temperature due to heat transfer through the skin have a major influence on sleep regulation. Traditional measures of skin temperature are often complicated by extensive wiring and are not practical for use in normal living conditions. This review describes studies examining the reliability, validity and utility of the iButton®, a wireless peripheral thermometry device, in sleep/wake research. A review was conducted of English language literature on the iButton as a measure of circadian body temperature rhythms associated with the sleep/wake cycle. Seven studies of the iButtton as a measure of human body temperature were included. The iButton was found to be a reliable and valid measure of body temperature. Its application to human skin was shown to be comfortable and tolerable with no significant adverse reactions. Distal skin temperatures were negatively correlated with sleep/wake activity, and the temperature gradient between the distal and proximal skin (DPG) was identified as an accurate physiological correlate of sleep propensity. Methodological issues included site of data logger placement, temperature masking factors, and temperature data analysis. The iButton is an inexpensive, wireless data logger that can be used to obtain a valid measurement of human skin temperature. It is a practical alternative to traditional measures of circadian rhythms in sleep/wake research. Further research is needed to determine the utility of the iButton in vulnerable populations, including those with neurodegenerative disorders and memory impairment and pediatric populations. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. An experimental study on the effect of noise and sleep loss on human performance using the measure of TCI during NPP maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Hyun Jun

    2008-02-15

    There are various stressors in NPP maintenance, such as environmental stressors and work-related stressors. These stressors degrade human performance and increase human error. Stress has not been largely considered as a factor of human error in root cause analyses. Recently, however, regulatory bodies and research institutes have worked to manage the physical condition of the operator and improve the environment and methods of NPP maintenance. These efforts have focused on reducing the incidence of human error due to stress. It is necessary to study how much stress affects human performance before these efforts are complete. The objectives of the present study are to formulate a Task Concentration Index (TCI) based on Electrocardiogram (ECG) signals in order to evaluate the degree to which a person concentrates on a task experimentally. With the TCI, the study will also evaluate the effects of noise and sleep loss on human performance during NPP maintenance tasks. Stress influences the efficiency of information processing and data input and output. Stress and human error are tightly linked in a closed-loop combination. The human body responds to stress by activating the nervous system and specific hormones. Therefore, physiological signals are changed by stress. A spectral analysis of Heart Rate Variability (HRV) provides a noninvasive technique for indirectly measuring sympathetic and parasympathetic modulation during specific tasks. The high-frequency component (HF, 0.15∼0.4Hz) reflects momentary respiration and is mediated by the parasympathetic nervous system. The low-frequency component (LF, 0.04∼0.15Hz) has been interpreted mainly as an indicator of sympathetic influences (especially when expressed in normalized units). When the level of stress is high, the Normalized Low Frequency component (NoLF) of HRV signals is generally higher than the normal state. The difference in NoLF readings between a normal state and during a task could be used to evaluate

  10. Hope, perceived financial risk and propensity for indebtedness

    National Research Council Canada - National Science Library

    Barros, Lucia; Botelho, Delane

    2012-01-01

    ... (MacInnis and Mello, 2005). The authors aim to investigate the relationships among hope, risk perception related to purchasing and consumption and propensity for indebtedness by conducting two empirical studies...

  11. Is the propensity to complain increasing over time?

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn; Thøgersen, John; Poulsen, Carsten Stig

    2006-01-01

    The purpose of this paper is twofold. First we present some of the measurement problems involved in interpreting consumer complaint data. Second we provide some unique longitudinal results on complaint propensity documenting that, in spite of a doubling of the number of cases submitted to the Dan...... to the Danish National Complaints Board, the propensity to complain in Denmark has not increased in the past 25 years. We conclude by discussing how the analysis could be extended from merely describing to explaining the variation in propensity to complain across consumers.......The purpose of this paper is twofold. First we present some of the measurement problems involved in interpreting consumer complaint data. Second we provide some unique longitudinal results on complaint propensity documenting that, in spite of a doubling of the number of cases submitted...

  12. Sleep walking

    Science.gov (United States)

    ... during REM sleep, it is part of REM behavior disorder and tends to happen near morning. As people age, they have less N3 sleep. This is why sleepwalking is much more common in children and young adults. The cause of sleepwalking in children is usually ...

  13. Employment propensity: The roles of mental and physical health

    OpenAIRE

    Gail Pacheco; Webber, Don J

    2011-01-01

    This paper presents an investigation into the impacts of mental and physical health on the propensity to be employed. Health status is parameterised using three physical and three mental health indicators. After controlling for various socioeconomic factors, the application of limited dependent variable regression techniques generates results which indicate that activity-limiting physical health and accomplishment-limiting mental health issues significantly affect the propensity to be employe...

  14. A qualitative exploration of adolescent perceptions of healthy sleep in Tucson, Arizona, USA.

    Science.gov (United States)

    Orzech, Kathryn M

    2013-02-01

    Adolescents in the United States are known to be sleep deprived; early school start times, a biological propensity to stay up late, and a variety of wake-inducing activities lead to teens who often do not sleep enough. This chronic lack of sleep has measurable negative effects on health and well-being for adolescents. Though research has documented adolescent sleep behavior, few studies have addressed perceptions of sleep. The purpose of this study was to identify common sources of sleep information for a sample of Southwestern adolescents and examine general message content delivered to adolescents by each source. A convenience sample of 51 adolescents (mean age 14.5) completed a semi-structured, in-person interview between October 2006 and November 2007 in a Tucson, Arizona high school. Participant observation and a brief questionnaire regarding parent behavior were used to triangulate results. Parents, teachers, and in some cases the media stressed the importance of sleep for teens, while friends typically complained of tiredness. Individual experiences of sleep were reported to shape future sleep behavior. Rationales for adequate sleep included value placed on alertness, health, and achievement. Improving sleep in adolescents will not only require further education of the "sleep messengers" about the negative health consequences of inadequate sleep, but a larger cultural shift in how healthy sleep for teenagers is conceived and prioritized by schools, families and adolescents themselves. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Hope, Perceived Financial Risk and Propensity for Indebtedness

    Directory of Open Access Journals (Sweden)

    Lucia Barros

    2012-10-01

    Full Text Available Hope is an important construct in marketing, since it is an antecedent of important marketing variables, such as trust, expectation and satisfaction (MacInnis & Mello, 2005. Specifically, literature suggests that hope plays an important influence in risk perception (MacInnis & Mello, 2005 and propensity for indebtedness (Fleming, 2008. Thus, we aim to investigate the relationships among hope, risk perception related to purchasing and consumption and propensity for indebtedness by conducting two empirical studies. The first is a laboratory experiment, which accessed hope and risk perception of getting a mortgage loan. The second is a survey, investigating university students’ propensity to get indebted to pay for their university tuition, analyzed through the Structural Equations Modeling method. These studies found that higher levels of hope predicted an increase in the propensity to accept the mortgage loan, independent of actual risks, and an increase in the propensity of college students to get indebted to pay for their studies. In addition, the first study suggests that hope may lead to a decrease in risk perception, which, however, wasn’t confirmed by the second study. Finally, this research offers some methodological contributions, using an experimental approach to understand hope and its relationship with perceived financial risk and propensity for indebtedness.

  16. Adolescent Changes in the Homeostatic and Circadian Regulation of Sleep

    OpenAIRE

    Hagenauer, M.H.; Perryman, J.I.; Lee, T. M.; Carskadon, M.A.

    2009-01-01

    Sleep deprivation among adolescents is epidemic. We argue that this sleep deprivation is due in part to pubertal changes in the homeostatic and circadian regulation of sleep. These changes promote a delayed sleep phase that is exacerbated by evening light exposure and incompatible with aspects of modern society, notably early school start times. In this review of human and animal literature, we demonstrate that delayed sleep phase during puberty is likely a common phenomenon in mammals, not s...

  17. Developmental Changes in Sleep Oscillations during Early Childhood

    OpenAIRE

    Eckehard Olbrich; Thomas Rusterholz; Monique K LeBourgeois; Peter Achermann

    2017-01-01

    Although quantitative analysis of the sleep electroencephalogram (EEG) has uncovered important aspects of brain activity during sleep in adolescents and adults, similar findings from preschool-age children remain scarce. This study utilized our time-frequency method to examine sleep oscillations as characteristic features of human sleep EEG. Data were collected from a longitudinal sample of young children (n = 8; 3 males) at ages 2, 3, and 5 years. Following sleep stage scoring, we detected a...

  18. Developmental Changes in Sleep Oscillations during Early Childhood

    OpenAIRE

    Olbrich, Eckehard; Rusterholz, Thomas; Monique K LeBourgeois; ACHERMANN, PETER

    2017-01-01

    Although quantitative analysis of the sleep electroencephalogram (EEG) has uncovered important aspects of brain activity during sleep in adolescents and adults, similar findings from preschool-age children remain scarce. This study utilized our time-frequency method to examine sleep oscillations as characteristic features of human sleep EEG. Data were collected from a longitudinal sample of young children (n=8; 3 males) at ages 2, 3, and 5 years. Following sleep stage scoring, we detected and...

  19. Mathematical models for sleep-wake dynamics: a comparison

    OpenAIRE

    Skeldon, AC; Dijk, D-J; Derks, G.

    2013-01-01

    Sleep is essential for the maintenance of human life, yet many features of sleep are poorly understood and mathematical models are an important tool for probing proposed biological mechanisms. The most well-known mathematical model of sleep regulation, the two-process model, models the sleep-wake cycle by two oscillators: a circadian oscillator and a homeostatic oscillator. An alternative, more recent, model considers the reciprocal interaction of sleep promoting neurons and the ascending aro...

  20. In search of objective components for sleep quality indexing in normal sleep

    OpenAIRE

    Rosipal, Roman; Lewandowski, Achim; Dorffner, Georg

    2013-01-01

    The main goal of this study was to investigate to what extent polysomnographic (PSG) recordings of nocturnal human sleep can provide information about sleep quality in terms of correlation with a set of daytime measures. These measures were designed with the aim of comprising selected quality of night sleep and consist of subjective sleep quality ratings, neuropsychological tests and physiological parameters. First, a factor analysis model was applied to the large number of daytime measures o...

  1. Trait Impulsive Choice Predicts Resistance to Extinction and Propensity to Relapse to Cocaine Seeking: A Bidirectional Investigation

    NARCIS (Netherlands)

    Broos, N.; Diergaarde, L.; Schoffelmeer, A.N.M.; Pattij, T.; de Vries, T.J.

    2012-01-01

    Despite the strong association between impulsivity and addiction in humans, it is still a matter of debate whether impulsive choice predisposes to, or results from, drug dependence. Furthermore, it is unknown whether treating impulsivity can protect against relapse propensity. Therefore, this study

  2. Obesity and sleep disturbances: meaningful sub-typing of obesity.

    Science.gov (United States)

    Vgontzas, Alexandros N; Bixler, Edward O; Chrousos, George P; Pejovic, Slobodanka

    2008-10-01

    Obesity, excessive daytime sleepiness (EDS), and self-reported short sleep duration appear to be on the rise, while there is evidence that obesity and these sleep disorders are strongly connected. In this paper, we review data that challenge the common belief that the sleep apnoea and sleep loss, frequently associated with obesity, are the primary determinants of obesity-related objective daytime sleepiness and subjective fatigue (tiredness without increased sleep propensity). Specifically, obesity is associated with objective and subjective EDS regardless of the presence of sleep apnoea. The association between obesity and EDS was confirmed in recent studies of large random samples of the general population or clinical samples, which showed that the primary determinants of subjective EDS were depression, metabolic disturbances, i.e. obesity/diabetes and insulin resistance, and lack of physical activity, and, secondarily, sleep apnoea or sleep loss. Paradoxically, within the obese, with or without sleep apnoea, those who slept objectively better at night are sleepier (objectively) during the day than those who slept worse. The distinguishing factor between those that slept better vs. those that slept worse appears to be level of emotional stress. Furthermore, many studies reported that obesity is associated with self-reported short sleep duration; however, it appears that short sleep duration is a marker of emotional stress rather than a reflection of true sleep loss. Based on these data, we propose that obesity-related deeper sleep and objective EDS are primarily related to metabolic disturbances, whereas obesity-related poorer sleep and subjective fatigue appear to be the result of psychological distress. Furthermore, based on data from studies in normal controls and patients with sleep disorders, it appears that the interaction of the hypothalamic-pituitary-adrenal (HPA) axis and pro-inflammatory cytokines determines the level of sleep/arousal within the 24-hour

  3. Physiology of normal sleep in adolescents.

    Science.gov (United States)

    Tarokh, Leila; Raffray, Tifenn; Van Reen, Eliza; Carskadon, Mary A

    2010-12-01

    Among the many behavioral changes associated with adolescent development are later bedtimes and less sleep. This article presents an overview of healthy adolescent sleep in humans along with a review of the maturation of homeostatic (process S) and circadian (process C) processes regulating sleep. We propose that maturational changes to the homeostatic and circadian processes push adolescents toward later bedtimes, while societal demands, such as early school start times, result in a pattern of insufficient and ill-timed sleep. The implications of sleep curtailment during this developmental period are discussed.

  4. Sleep Transitions in Hypocretin-Deficient Narcolepsy

    DEFF Research Database (Denmark)

    Sorensen, Gertrud Laura; Knudsen, Stine; Jennum, Poul

    2013-01-01

    Narcolepsy is characterized by instability of sleep-wake, tonus, and rapid eye movement (REM) sleep regulation. It is associated with severe hypothalamic hypocretin deficiency, especially in patients with cataplexy (loss of tonus). As the hypocretin neurons coordinate and stabilize the brain......'s sleep-wake pattern, tonus, and REM flip-flop neuronal centers in animal models, we set out to determine whether hypocretin deficiency and/or cataplexy predicts the unstable sleep-wake and REM sleep pattern of the human phenotype....

  5. Medicines for sleep

    Science.gov (United States)

    Benzodiazepines; Sedatives; Hypnotics; Sleeping pills; Insomnia - medicines; Sleep disorder - medicines ... are commonly used to treat allergies. While these sleep aids are not addictive, your body becomes used ...

  6. Sleep and sedation in the pediatric intensive care unit.

    Science.gov (United States)

    Carno, Margaret-Ann; Connolly, Heidi V

    2005-09-01

    Sleep is an important and necessary function of the human body. Somatic growth and cellular repair occur during sleep. Critically ill children have disturbed sleep while in the pediatric intensive care unit related both to the illness itself and to light, noise, and caregiver activities disrupting an environment conducive to sleep. Medications administered in the pediatric intensive care unit can also disrupt sleep. This article reviews what is known about sleep in the pediatric intensive care unit and the effects of common sedation medications on sleep.

  7. Sleep deprivation and gene expression.

    Science.gov (United States)

    da Costa Souza, Annie; Ribeiro, Sidarta

    2015-01-01

    Sleep occurs in a wide range of animal species as a vital process for the maintenance of homeostasis, metabolic restoration, physiological regulation, and adaptive cognitive functions in the central nervous system. Long-term perturbations induced by the lack of sleep are mostly mediated by changes at the level of transcription and translation. This chapter reviews studies in humans, rodents, and flies to address the various ways by which sleep deprivation affects gene expression in the nervous system, with a focus on genes related to neuronal plasticity, brain function, and cognition. However, the effects of sleep deprivation on gene expression and the functional consequences of sleep loss are clearly not restricted to the cognitive domain but may include increased inflammation, expression of stress-related genes, general impairment of protein translation, metabolic imbalance, and thermal deregulation.

  8. Estimating Adolescent Sleep Need Using Dose-Response Modelling.

    Science.gov (United States)

    Short, Michelle A; Weber, Nathan; Reynolds, Chelsea; Coussens, Scott; Carskadon, Mary A

    2018-01-06

    This study will, (a) estimate the nightly sleep need of human adolescents, (b) determine the time course and severity of sleep-related deficits when sleep is reduced below this optimal quantity, and (c) determine whether sleep restriction perturbs the circadian system as well as the sleep homeostat. Thirty-four adolescents aged 15 to 17 years spent 10 days and 9 nights in the sleep laboratory. Between two baseline nights and two recovery nights with 10-hours' time in bed (TIB) per night, participants experienced either severe sleep restriction (5-hr TIB), moderate sleep restriction (7.5-hr TIB), or no sleep restriction (10-hr TIB) for 5 nights. A 10-minute psychomotor vigilance task (PVT; lapse = response after 500 ms) and the Karolinska Sleepiness Scale were administered every 3 hours during wake. Salivary dim light melatonin onset was calculated at baseline and after 4 nights of each sleep dose to estimate circadian phase. Dose-dependent deficits to sleep duration, circadian phase timing, lapses of attention and subjective sleepiness occurred. Less TIB resulted in less sleep, more lapses of attention, greater subjective sleepiness and larger circadian phase delays. Sleep need estimated from 10-hr TIB sleep opportunities was approximately 9 hours, while modelling PVT lapse data suggested that 9.35 hr of sleep is needed to maintain optimal sustained attention performance. Sleep restriction perturbs homeostatic and circadian systems, leading to dose-dependent deficits to sustained attention and sleepiness. Adolescents require more sleep for optimal functioning than typically obtained.

  9. Effects of thermal environment on sleep and circadian rhythm

    Directory of Open Access Journals (Sweden)

    Okamoto-Mizuno Kazue

    2012-05-01

    Full Text Available Abstract The thermal environment is one of the most important factors that can affect human sleep. The stereotypical effects of heat or cold exposure are increased wakefulness and decreased rapid eye movement sleep and slow wave sleep. These effects of the thermal environment on sleep stages are strongly linked to thermoregulation, which affects the mechanism regulating sleep. The effects on sleep stages also differ depending on the use of bedding and/or clothing. In semi-nude subjects, sleep stages are more affected by cold exposure than heat exposure. In real-life situations where bedding and clothing are used, heat exposure increases wakefulness and decreases slow wave sleep and rapid eye movement sleep. Humid heat exposure further increases thermal load during sleep and affects sleep stages and thermoregulation. On the other hand, cold exposure does not affect sleep stages, though the use of beddings and clothing during sleep is critical in supporting thermoregulation and sleep in cold exposure. However, cold exposure affects cardiac autonomic response during sleep without affecting sleep stages and subjective sensations. These results indicate that the impact of cold exposure may be greater than that of heat exposure in real-life situations; thus, further studies are warranted that consider the effect of cold exposure on sleep and other physiological parameters.

  10. Inter-Individual Differences In Habitual Sleep Timing and Entrained Phase of Endogenous Circadian Rhythms of BMAL1, PER2 and PER3 mRNA in Human Leukocytes

    Science.gov (United States)

    Archer, Simon N.; Viola, Antoine U.; Kyriakopoulou, Vanessa; von Schantz, Malcolm; Dijk, Derk-Jan

    2008-01-01

    Study Objectives: Individual sleep timing differs and is governed partly by circadian oscillators, which may be assessed by hormonal markers, or by clock gene expression. Clock gene expression oscillates in peripheral tissues, including leukocytes. The study objective was to determine whether the endogenous phase of these rhythms, assessed in the absence of the sleep-wake and light-dark cycle, correlates with habitual sleep-wake timing. Design: Observational, cross-sectional. Setting: Home environment and Clinical Research Center. Participants: 24 healthy subjects aged 25.0 ± 3.5 (SD) years. Measurements: Actigraphy and sleep diaries were used to characterize sleep timing. Circadian rhythm phase and amplitude of plasma melatonin, cortisol, and BMAL1, PER2, and PER3 expression were assessed during a constant routine. Results: Circadian oscillations were more robust for PER3 than for BMAL1 or PER2. Average peak timings were 6:05 for PER3, 8:06 for PER2, 15:06 for BMAL1, 4:20 for melatonin, and 10:49 for cortisol. Individual sleep-wake timing correlated with the phases of melatonin and cortisol. Individual PER3 rhythms correlated significantly with sleep-wake timing and the timing of melatonin and cortisol, but those of PER2 and BMAL1 did not reach significance. The correlation between sleep timing and PER3 expression was stronger in individuals homozygous for the variant of the PER3 polymorphism that is associated with morningness. Conclusions: Individual phase differences in PER3 expression during a constant routine correlate with sleep timing during entrainment. PER3 expression in leukocytes represents a useful molecular marker of the circadian processes governing sleep-wake timing. Citation: Archer SN; Viola AU; Kyriakopoulou V; von Schantz M; Dijk DJ. Inter-individual differences in habitual sleep timing and entrained phase of endogenous circadian rhythms of BMAL1, PER2 and PER3 mRNA in human leukocytes. SLEEP 2008;31(5):608-617. PMID:18517031

  11. Effect of chronic stress and sleep deprivation on both flow-mediated dilation in the brachial artery and the intracellular magnesium level in humans.

    Science.gov (United States)

    Takase, Bonpei; Akima, Takashi; Uehata, Akimi; Ohsuzu, Fumitaka; Kurita, Akira

    2004-04-01

    Chronic mental and physical stress has been suggested to be a trigger for cardiovascular events. In addition, a reduction in levels of intracellular magnesium has been reported to cause vasoconstriction while enhancing platelet-dependent thrombosis. The purpose of this study was to investigate whether chronic stress affects endothelial function and intracellular magnesium levels in humans. Flow-mediated dilation (endothelium-dependent vasodilation) and sublingual nitroglycerin-induced dilation (0.3 mg, endothelium-independent vasodilation) were measured in the brachial artery in 30 healthy male college students, aged 22 +/- 1 years, using high-resolution ultrasound both before and immediately after a 4-week final term examination period. Erythrocyte magnesium concentration was measured simultaneously. All students had chronic sleep deprivation for 4 weeks, during which sleep lasted students were under great stress to pass the examination. This condition was considered to be chronic stress. Chronic stress decreased flow-mediated dilation and erythrocyte magnesium concentration (from 7.4 +/- 3.0 to 3.7 +/- 2.3%, p < 0.05; from 5.7 +/- 0.4 to 5.5 +/- 0.4 mg/ml, p < 0.05, respectively). The change in flow-mediated dilation correlated significantly with that of the erythrocyte magnesium concentration (r = 0.43, p < 0.05), but not with nitroglycerin-induced dilation. Chronic stress was found to attenuate endothelial function, which may also be associated with a reduction in the intracellular magnesium level in humans.

  12. Sleep and performance--recent trends.

    Science.gov (United States)

    Himashree, Gidugu; Banerjee, P K; Selvamurthy, W

    2002-01-01

    Sleep and sleep deprivation are intimately related to performance. Sleep management of people working in different sectors of the society like multi shift workers, nurses, doctors, students in professional schools and the armed forces has a great bearing on performance, health and safety of the subject population. The detrimental effects of sleep deprivation on psychological performance are indicated as increased lapsing, cognitive slowing, memory impairment, decrease in vigilance and sustained attention and shift in optimum response capability. Its effects on physical performance are manifested as decline in ability to perform maximal exercise, self-selected walking pace and increase in perceived exertion. Sleep deprivation appears to have no effect in respect of muscle contractile properties and maximum anaerobic power. At high altitude (HA), there is a reduction in NREM sleep with frequent awakening due to hypoxia as a physiological adaptive measure to prevent accentuation of hypoxemia due to sleep-hypoventilation. Total sleep deprivation for 48 hours at high altitude can affect the acclimatization status, thermoregulation efficiency and cognitive functions. The concept of 'sleepiness' has also been studied, as it is an emerging concept for better understanding of the effects of sleep deprivation and its effects on performance. A special mention of sustained operations in the armed forces has been made keeping in mind its uniqueness in challenging the normal sleep-work schedule and its deployment in extreme environment and operational condition. This article reviews in detail the functions of sleep, its requirement and the effects of sleep deprivation on human performance.

  13. A Two-Step Bayesian Approach for Propensity Score Analysis: Simulations and Case Study

    Science.gov (United States)

    Kaplan, David; Chen, Jianshen

    2012-01-01

    A two-step Bayesian propensity score approach is introduced that incorporates prior information in the propensity score equation and outcome equation without the problems associated with simultaneous Bayesian propensity score approaches. The corresponding variance estimators are also provided. The two-step Bayesian propensity score is provided for…

  14. Sleep in Alzheimer's Disease–Beyond Amyloid

    Directory of Open Access Journals (Sweden)

    Jerrah K. Holth

    2017-01-01

    Full Text Available Sleep disorders are prevalent in Alzheimer's disease (AD and a major cause of institutionalization. Like AD pathology, sleep abnormalities can appear years before cognitive decline and may be predictive of dementia. A bidirectional relationship between sleep and amyloid β (Aβ has been well established with disturbed sleep and increased wakefulness leading to increased Aβ production and decreased Aβ clearance; whereas Aβ deposition is associated with increased wakefulness and sleep disturbances. Aβ fluctuates with the sleep-wake cycle and is higher during wakefulness and lower during sleep. This fluctuation is lost with Aβ deposition, likely due to its sequestration into amyloid plaques. As such, Aβ is believed to play a significant role in the development of sleep disturbances in the preclinical and clinical phases of AD. In addition to Aβ, the influence of tau AD pathology is likely important to the sleep disturbances observed in AD. Abnormal tau is the earliest observable AD-like pathology in the brain with abnormal tau phosphorylation in many sleep regulating regions such as the locus coeruleus, dorsal raphe, tuberomammillary nucleus, parabrachial nucleus, and basal forebrain prior to the appearance of amyloid or cortical tau pathology. Furthermore, human tau mouse models exhibit AD-like sleep disturbances and sleep changes are common in other tauopathies including frontotemporal dementia and progressive supranuclear palsy. Together these observations suggest that tau pathology can induce sleep disturbances and may play a large role in the sleep disruption seen in AD. To elucidate the relationship between sleep and AD it will be necessary to not only understand the role of amyloid but also tau and how these two pathologies, together with comorbid pathology such as alpha-synuclein, interact and affect sleep regulation in the brain.

  15. Excessive daytime sleepiness, nocturnal sleep duration and ...

    African Journals Online (AJOL)

    denise

    2011-12-04

    Dec 4, 2011 ... The average adult human sleeps for about 8 of every 24 hours.1. Most of our sleep occurs at night, since we function predominantly during the day and it is necessary to be awake and alert. Under certain conditions, humans are unable to maintain the state of wakefulness needed for daytime functioning.

  16. Health related quality of life among myocardial infarction survivors in the United States: a propensity score matched analysis.

    Science.gov (United States)

    Mollon, Lea; Bhattacharjee, Sandipan

    2017-12-04

    Little is known regarding the health-related quality of life among myocardial infarction (MI) survivors in the United States. The purpose of this population-based study was to identify differences in health-related quality of life domains between MI survivors and propensity score matched controls. This retrospective, cross-sectional matched case-control study examined differences in health-related quality of life (HRQoL) among MI survivors of myocardial infarction compared to propensity score matched controls using data from the 2015 Behavioral Risk Factor Surveillance System (BRFSS) survey. Propensity scores were generated via logistic regression for MI survivors and controls based on gender, race/ethnicity, age, body mass index (BMI), smoking status, and comorbidities. Chi-square tests were used to compare differences between MI survivors to controls for demographic variables. A multivariate analysis of HRQoL domains estimated odds ratios. Life satisfaction, sleep quality, and activity limitations were estimated using binary logistic regression. Social support, perceived general health, perceived physical health, and perceived mental health were estimated using multinomial logistic regression. Significance was set at p 15 days in the month (AOR = 1.63, 95% CI: 1.46-1.83) and poor mental health >15 days in the month (AOR = 1.25, 95% CI: 1.07-1.46) compared to matched controls. There was no difference in survivors compared to controls in level of emotional support (rarely/never: AOR = 0.75, 95% CI: 0.48-1.18; sometimes: AOR = 0.73, 95% CI: 0.41-1.28), hours of recommended sleep (AOR = 1.14, 95% CI: 0.94-1.38), or life satisfaction (AOR = 1.62, 95% CI: 0.99-2.63). MI survivors experienced lower HRQoL on domains of general health, physical health, daily activity, and mental health compared to the general population.

  17. Sleep Apnea (For Parents)

    Science.gov (United States)

    ... Braces Eating Disorders Mitral Valve Prolapse Arrhythmias Obstructive Sleep Apnea KidsHealth > For Parents > Obstructive Sleep Apnea Print ... kids and teens can develop it, too. About Sleep Apnea Sleep apnea happens when a person stops ...

  18. Pediatric sleep apnea

    Science.gov (United States)

    Sleep apnea - pediatric; Apnea - pediatric sleep apnea syndrome; Sleep-disordered breathing - pediatric ... During sleep, all of the muscles in the body become more relaxed. This includes the muscles that help keep ...

  19. Obstructive sleep apnea - adults

    Science.gov (United States)

    Sleep apnea - obstructive - adults; Apnea - obstructive sleep apnea syndrome - adults; Sleep-disordered breathing - adults; OSA - adults ... When you sleep, all of the muscles in your body become more relaxed. This includes the muscles that help keep your ...

  20. Advances in Sleep Studies

    Science.gov (United States)

    ... page please turn JavaScript on. Feature: Sleep Disorders Advances in Sleep Studies Past Issues / Summer 2015 Table ... Disorders / Tips for Getting A Good Night's Sleep / Advances In Sleep Studies Summer 2015 Issue: Volume 10 ...

  1. What Are Sleep Studies?

    Science.gov (United States)

    ... Sleep Studies Related Topics CPAP Narcolepsy Sleep Apnea Sleep Deprivation and Deficiency Send a link to NHLBI to ... away after they are removed. Your doctor will review your sleep study test results and develop a treatment plan ...

  2. Sleep Disorders (PDQ)

    Science.gov (United States)

    ... Sleep disorders are more common in people with cancer. While sleep disorders affect a small number of healthy people, as many as half of patients with cancer have problems sleeping. The sleep disorders ...

  3. Sleep Terrors (Night Terrors)

    Science.gov (United States)

    ... can contribute to sleep terrors, such as: Sleep deprivation and extreme tiredness Stress Sleep schedule disruptions, travel ... such as depression and anxiety In adults, alcohol use Risk factors Sleep terrors are more common if ...

  4. Sleep Problems

    Science.gov (United States)

    ... Drugs to treat Sleep Disorders Tips on using CPAP machine (video) More in For Women Medication Safety ... Emergency Preparedness International Programs News & Events Training & Continuing Education Inspections & Compliance Federal, State & Local Officials Consumers Health ...

  5. Sleep Disorders

    Science.gov (United States)

    ... sufficient to promote a normal circadian rhythm. Avoid sedentary activities during the day. Participate in activities outside ... the name. People with rapid eye movement sleep behavior disorder (RBD) do not have the normal relaxation ...

  6. Refreshing Sleep and Sleep Continuity Determine Perceived Sleep Quality

    Directory of Open Access Journals (Sweden)

    Eva Libman

    2016-01-01

    Full Text Available Sleep quality is a construct often measured, employed as an outcome criterion for therapeutic success, but never defined. In two studies we examined appraised good and poor sleep quality in three groups: a control group, individuals with obstructive sleep apnea, and those with insomnia disorder. In Study 1 we used qualitative methodology to examine good and poor sleep quality in 121 individuals. In Study 2 we examined sleep quality in 171 individuals who had not participated in Study 1 and evaluated correlates and predictors of sleep quality. Across all six samples and both qualitative and quantitative methodologies, the daytime experience of feeling refreshed (nonrefreshed in the morning and the nighttime experience of good (impaired sleep continuity characterized perceived good and poor sleep. Our results clarify sleep quality as a construct and identify refreshing sleep and sleep continuity as potential clinical and research outcome measures.

  7. Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

    Energy Technology Data Exchange (ETDEWEB)

    Miletich, R.S.

    1985-01-01

    The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and /sup 3/H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by ..cap alpha..-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period, phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S/sub 2/ episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. /sup 3/H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system.

  8. Understanding sleep-wake behavior and sleep disorders in children: the value of a model.

    Science.gov (United States)

    Jenni, Oskar G; LeBourgeois, Monique K

    2006-05-01

    Sleep-wake problems such as night wakings, excessive crying, or difficulties in falling asleep are frequent behavioral issues during childhood. Maturational changes in sleep and circadian regulation likely contribute to the development and maintenance of such problems. This review highlights the recent research examining bioregulatory sleep mechanisms during development and provides a model for predicting sleep-wake behavior in young humans. Findings demonstrate that circadian and sleep homeostatic processes exhibit maturational changes during the first two decades of life. The developing interaction of both processes may be a key determinant of sleep-wake and crying behavior in infancy. Evidence shows that the dynamics of sleep homeostatic processes slow down in the course of childhood (i.e., sleep pressure accumulates more slowly with increasing age) enabling children to be awake for consolidated periods during the day. Another current topic is the adolescent sleep phase delay, which appears to be driven primarily by maturational changes in sleep homeostatic and circadian processes. The two-process model of sleep regulation is a valuable framework for understanding and predicting sleep-wake behavior in young humans. Such knowledge is important for improving anticipatory guidance, parental education, and patient care, as well as for developing appropriate social policies.

  9. Sleep Tips: 7 Steps to Better Sleep

    Science.gov (United States)

    ... turn every night. Consider simple tips for better sleep, from setting a sleep schedule to including physical activity in your daily ... factors that can interfere with a good night's sleep — from work stress and family responsibilities to unexpected ...

  10. Comparisons of Portable Sleep Monitors of Different Modalities: Potential as Naturalistic Sleep Recorders

    Directory of Open Access Journals (Sweden)

    Masahiro Matsuo

    2016-07-01

    Full Text Available Background: Humans spend more than a fourth of their life sleeping, and sleep quality has been significantly linked to health. However, the objective examination of ambulatory sleep quality remains a challenge, since sleep is a state of unconsciousness, which limits the reliability of self-reports. Therefore, a non-invasive, continuous, and objective method for the recording and analysis of naturalistic sleep is required.Objective: Portable sleep recording devices provide a suitable solution for the ambulatory analysis of sleep quality. In this study, the performance of two activity-based sleep monitors (Actiwatch and MTN-210 and a single-channel EEG-based sleep monitor (SleepScope were compared in order to examine their reliability for the assessment of sleep quality.Methods: Twenty healthy adults were recruited for this study. First, data from daily activity recorded by Actiwatch and MTN-210 were compared to determine whether MTN-210, a more affordable device, could yield data similar to Actiwatch, the de-facto standard. In addition, sleep detection ability was examined using data obtained by polysomnography as reference. One simple analysis included comparing the sleep/wake detection ability of Actiwatch, MTN-210, and SleepScope. Furthermore, the fidelity of sleep stage determination was examined using SleepScope in finer time resolution. Results: The results indicate that MTN-210 demonstrates an activity pattern comparable to that of Actiwatch, although their sensitivity preferences were not identical. Moreover, MTN-210 provides assessment of sleep duration comparable to that of the wrist-worn Actiwatch when MTN-210 was attached to the body. SleepScope featured superior overall sleep detection performance among the three methods tested. Furthermore, SleepScope was able to provide information regarding sleep architecture, although systemic bias was found. Conclusion: The present results suggest that single-channel EEG-based sleep monitors are

  11. Developmental stability and human violence

    National Research Council Canada - National Science Library

    Bryant Furlow; Steven W. Gangestad; Tara Armijo-Prewitt

    1998-01-01

    ...), is a major source of phenotypic and behavioural variation, yet researchers have largely ignored its potential role in the ontogeny of individual propensities toward human aggression and violence...

  12. Sleep in Othello

    OpenAIRE

    Dimsdale, Joel E.

    2009-01-01

    Some of our best descriptions of sleep disorders come from literature. While Shakespeare is well known for his references to insomnia and sleep walking, his works also demonstrate a keen awareness of many other sleep disorders. This paper examines sleep themes in Shakespeare's play Othello. The play indicates Shakespeare's astute eye for sleep deprivation, sexual parasomnias, and effects of stress and drugs on sleep.

  13. Alternative reproductive tactics and the propensity of hybridization.

    Science.gov (United States)

    Tynkkynen, K; Raatikainen, K J; Häkkilä, M; Haukilehto, E; Kotiaho, J S

    2009-12-01

    One explanation for hybridization between species is the fitness benefits it occasionally confers to the hybridizing individuals. This explanation is possible in species that have evolved alternative male reproductive tactics: individuals with inferior tactics might be more prone to hybridization provided it increases their reproductive success and fitness. Here we experimentally tested whether the propensity of hybridization in the wild depends on male reproductive tactic in Calopteryx splendens damselflies. Counter to our expectation, it was males adopting the superior reproductive tactic (territoriality) that had greatest propensity to hybridize than males adopting the inferior tactics (sneakers and floaters). Moreover, among the territorial males, the most ornamented males had greatest propensity to hybridize whereas the pattern was reversed in the sneaker males. Our results suggest that there is fluctuating selection on male mate discrimination against heterospecific females depending on both ornament size and the male's reproductive tactic.

  14. [Sleep and metabolic disorders].

    Science.gov (United States)

    Micić, Dragan D; Šumarac-Dumanović, Mirjana; Šušić, Veselinka; Pejković, Danica; Polovina, Snežana

    2011-01-01

    In the 20th century, the prevalence of obesity has been increasing worldwide at an alarming rate and it is followed by an increase in the diseases for which obesity is major risk factor, like metabolic syndrome, diabetes type 2 and hypertension. These facts has been resulting in explosion of investigation devoted to explanation of pathogenetic mechanisms of this serious social and medical problems with the main idea to find adequate way of prevention as well as of treatment. Together with the observed epidemy of obesity and Type 2 diabetes, it was found parallel tendency for sleep curtailment, that was confirmed in numerous epidemiological studies, that coincide with its beginning and progress with this two epidemies. This facts lead to investigations with the idea to try to explaine possible mechanisms of the association between sleep curtailment, obesity, type 2 diabetes, metabolic syndrome and polycistic ovary syndrome. Having in mind that insulin resistance is one of the fundamental pathogenetic mechanism in these disorders, numerous studies were done with the aim to explain association between sleep curtailment and insulin resistance in obesity, Type 2 diabetes, metabolic syndrome and polycistic ovary syndrome. It was demonstrated that sleep curtailment may affect energy homeostasis of human organism with the effects on body weight increase through three different ways: appetite increase, prolongation of time for food intake and through decrease of energy expenditure. There are several postulated mechanism for the effect of sleep curtailment on development of insulin resistance as well as for predisposition for Type 2 diabetes. Among possible mechanism are included: increase of sympathetic neuronal acitvity, decreased cerebral utilisation of glucose, increase in evening cortisol values, growth hormone increase and disorder of neuroendocrine control of appetite which increases the risk for getting the body weight. Metabolic systems are of particular interest in

  15. Pathophysiology of Sleep Apnea

    Science.gov (United States)

    Veasey, Sigrid C.; Morgan, Barbara J.; O'Donnell, Christopher P.

    2010-01-01

    Sleep-induced apnea and disordered breathing refers to intermittent, cyclical cessations or reductions of airflow, with or without obstructions of the upper airway (OSA). In the presence of an anatomically compromised, collapsible airway, the sleep-induced loss of compensatory tonic input to the upper airway dilator muscle motor neurons leads to collapse of the pharyngeal airway. In turn, the ability of the sleeping subject to compensate for this airway obstruction will determine the degree of cycling of these events. Several of the classic neurotransmitters and a growing list of neuromodulators have now been identified that contribute to neurochemical regulation of pharyngeal motor neuron activity and airway patency. Limited progress has been made in developing pharmacotherapies with acceptable specificity for the treatment of sleep-induced airway obstruction. We review three types of major long-term sequelae to severe OSA that have been assessed in humans through use of continuous positive airway pressure (CPAP) treatment and in animal models via long-term intermittent hypoxemia (IH): 1) cardiovascular. The evidence is strongest to support daytime systemic hypertension as a consequence of severe OSA, with less conclusive effects on pulmonary hypertension, stroke, coronary artery disease, and cardiac arrhythmias. The underlying mechanisms mediating hypertension include enhanced chemoreceptor sensitivity causing excessive daytime sympathetic vasoconstrictor activity, combined with overproduction of superoxide ion and inflammatory effects on resistance vessels. 2) Insulin sensitivity and homeostasis of glucose regulation are negatively impacted by both intermittent hypoxemia and sleep disruption, but whether these influences of OSA are sufficient, independent of obesity, to contribute significantly to the “metabolic syndrome” remains unsettled. 3) Neurocognitive effects include daytime sleepiness and impaired memory and concentration. These effects reflect

  16. The Sleep Disorder Canine Narcolepsy Is Caused by a Mutation in the Hypocretin ( Orexin) Receptor 2 Gene

    National Research Council Canada - National Science Library

    Lin, Ling; Lin, Xiaoyan; Faraco, Juliette; Li, Robin; Kadotani, Hiroshi; Rogers, William; Qiu, Xiaohong; de Jong, Pieter J; Nishino, Seiji; Mignot, Emmanuel

    1999-01-01

    Narcolepsy is a disabling sleep disorder affecting humans and animals. It is characterized by daytime sleepiness, cataplexy, and striking transitions from wakefulness into rapid eye movement (REM) sleep...

  17. Acute versus chronic partial sleep deprivation in middle-aged people: differential effect on performance and sleepiness.

    Science.gov (United States)

    Philip, Pierre; Sagaspe, Patricia; Prague, Mélanie; Tassi, Patricia; Capelli, Aurore; Bioulac, Bernard; Commenges, Daniel; Taillard, Jacques

    2012-07-01

    To evaluate the effects of acute sleep deprivation and chronic sleep restriction on vigilance, performance, and self-perception of sleepiness. Habitual night followed by 1 night of total sleep loss (acute sleep deprivation) or 5 consecutive nights of 4 hr of sleep (chronic sleep restriction) and recovery night. Eighteen healthy middle-aged male participants (age [(± standard deviation] = 49.7 ± 2.6 yr, range 46-55 yr). Multiple sleep latency test trials, Karolinska Sleepiness Scale scores, simple reaction time test (lapses and 10% fastest reaction times), and nocturnal polysomnography data were recorded. Objective and subjective sleepiness increased immediately in response to sleep restriction. Sleep latencies after the second and third nights of sleep restriction reached levels equivalent to those observed after acute sleep deprivation, whereas Karolinska Sleepiness Scale scores did not reach these levels. Lapse occurrence increased after the second day of sleep restriction and reached levels equivalent to those observed after acute sleep deprivation. A statistical model revealed that sleepiness and lapses did not progressively worsen across days of sleep restriction. Ten percent fastest reaction times (i.e., optimal alertness) were not affected by acute or chronic sleep deprivation. Recovery to baseline levels of alertness and performance occurred after 8-hr recovery night. In middle-aged study participants, sleep restriction induced a high increase in sleep propensity but adaptation to chronic sleep restriction occurred beyond day 3 of restriction. This sleepiness attenuation was underestimated by the participants. One recovery night restores daytime sleepiness and cognitive performance deficits induced by acute or chronic sleep deprivation. Philip P; Sagaspe P; Prague M; Tassi P; Capelli A; Bioulac B; Commenges D; Taillard J. Acute versus chronic partial sleep deprivation in middle-aged people: differential effect on performance and sleepiness. SLEEP 2012;35(7):997-1002.

  18. On the influence of freight trains on humans: a laboratory investigation of the impact of nocturnal low frequency vibration and noise on sleep and heart rate.

    Science.gov (United States)

    Smith, Michael G; Croy, Ilona; Ogren, Mikael; Persson Waye, Kerstin

    2013-01-01

    A substantial increase in transportation of goods on railway may be hindered by public fear of increased vibration and noise leading to annoyance and sleep disturbance. As the majority of freight trains run during night time, the impact upon sleep is expected to be the most serious adverse effect. The impact of nocturnal vibration on sleep is an area currently lacking in knowledge. We experimentally investigated sleep disturbance with the aim to ascertain the impact of increasing vibration amplitude. The impacts of various amplitudes of horizontal vibrations on sleep disturbance and heart rate were investigated in a laboratory study. Cardiac accelerations were assessed using a combination of polysomnography and ECG recordings. Sleep was assessed subjectively using questionnaires. Twelve young, healthy subjects slept for six nights in the sleep laboratory, with one habituation night, one control night and four nights with a variation of vibration exposures whilst maintaining the same noise exposure. With increasing vibration amplitude, we found a decrease in latency and increase in amplitude of heart rate as well as a reduction in sleep quality and increase in sleep disturbance. We concluded that nocturnal vibration has a negative impact on sleep and that the impact increases with greater vibration amplitude. Sleep disturbance has short- and long-term health consequences. Therefore, it is necessary to define levels that protect residents against sleep disruptive vibrations that may arise from night time railway freight traffic.

  19. On the influence of freight trains on humans: a laboratory investigation of the impact of nocturnal low frequency vibration and noise on sleep and heart rate.

    Directory of Open Access Journals (Sweden)

    Michael G Smith

    Full Text Available BACKGROUND: A substantial increase in transportation of goods on railway may be hindered by public fear of increased vibration and noise leading to annoyance and sleep disturbance. As the majority of freight trains run during night time, the impact upon sleep is expected to be the most serious adverse effect. The impact of nocturnal vibration on sleep is an area currently lacking in knowledge. We experimentally investigated sleep disturbance with the aim to ascertain the impact of increasing vibration amplitude. METHODOLOGY/PRINCIPAL FINDINGS: The impacts of various amplitudes of horizontal vibrations on sleep disturbance and heart rate were investigated in a laboratory study. Cardiac accelerations were assessed using a combination of polysomnography and ECG recordings. Sleep was assessed subjectively using questionnaires. Twelve young, healthy subjects slept for six nights in the sleep laboratory, with one habituation night, one control night and four nights with a variation of vibration exposures whilst maintaining the same noise exposure. With increasing vibration amplitude, we found a decrease in latency and increase in amplitude of heart rate as well as a reduction in sleep quality and increase in sleep disturbance. CONCLUSIONS/SIGNIFICANCE: We concluded that nocturnal vibration has a negative impact on sleep and that the impact increases with greater vibration amplitude. Sleep disturbance has short- and long-term health consequences. Therefore, it is necessary to define levels that protect residents against sleep disruptive vibrations that may arise from night time railway freight traffic.

  20. The Time Course of the Probability of Transition Into and Out of REM Sleep

    Science.gov (United States)

    Bassi, Alejandro; Vivaldi, Ennio A.; Ocampo-Garcés, Adrián

    2009-01-01

    Study Objectives: A model of rapid eye movement (REM) sleep expression is proposed that assumes underlying regulatory mechanisms operating as inhomogenous Poisson processes, the overt results of which are the transitions into and out of REM sleep. Design: Based on spontaneously occurring REM sleep episodes (“Episode”) and intervals without REM sleep (“Interval”), 3 variables are defined and evaluated over discrete 15-second epochs using a nonlinear logistic regression method: “Propensity” is the instantaneous rate of into-REM transition occurrence throughout an Interval, “Volatility” is the instantaneous rate of out-of-REM transition occurrence throughout an Episode, and “Opportunity” is the probability of being in non-REM (NREM) sleep at a given time throughout an Interval, a requisite for transition. Setting: 12:12 light:dark cycle, isolated boxes. Participants: Sixteen male Sprague-Dawley rats Interventions: None. Spontaneous sleep cycles. Measurements and Results: The highest levels of volatility and propensity occur, respectively, at the very beginning of Episodes and Intervals. The new condition stabilizes rapidly, and variables reach nadirs at minute 1.25 and 2.50, respectively. Afterward, volatility increases markedly, reaching values close to the initial level. Propensity increases moderately, the increment being stronger through NREM sleep bouts occurring at the end of long Intervals. Short-term homeostasis is evidenced by longer REM sleep episodes lowering propensity in the following Interval. Conclusions: The stabilization after transitions into Episodes or Intervals and the destabilization after remaining for some time in either condition may be described as resulting from continuous processes building up during Episodes and Intervals. These processes underlie the overt occurrence of transitions. Citation: Bassi A; Vivaldi EA; Ocampo-Garcées A. The time course of the probability of transition into and out of REM sleep. SLEEP 2009

  1. Event-related potentials during forced awakening: a tool for the study of acute sleep inertia.

    Science.gov (United States)

    Bastuji, Hélène; Perrin, Fabien; Garcia-Larrea, Luis

    2003-09-01

    Sleep propensity and sleep inertia were assessed in 43 patients with excessive daytime sleepiness (EDS) and 21 sleep-deprived controls, using a forced awakening test under continuous electroencephalographic (EEG) recording. Event-related potentials (ERPs) were first obtained in waking, while participants performed a target detection auditory task. Subjects were then allowed to take a nap with lights off and sleep latency was calculated. After 3 min of continuous sleep, frequent and rare tones were suddenly presented again (and ERPs recorded) in a forced awakening condition, which was repeated a second time if patients fell asleep. ERPs in pre-nap wakefulness did not differ in patients and controls. On forced awakening, almost half (48%) of EDS patients retained morphologically normal ERPs, but showed a significant delay of P300 relative to waking. In the other half of the patients (and none of the controls), the N200/P300 complex to targets was replaced on forced awakening by high-amplitude negative waves ('sleep negativities'). Single subject analysis showed that 65% of patients had abnormal responses during forced awakening (significant P3 delay or sleep negativities), while only three of them (7%) had abnormal ERPs on wakefulness. The presence of sleep negativities was associated with shorter sleep latencies and increased target detection errors on forced awakening. Sleep negativities were more prevalent in narcolepsy and idiopathic hypersomnia than in EDS associated to psychiatric disorders. By combining sleep latency and ERP measures, the forced awakening test provided a robust and relatively rapid tool (45-60 min) to evaluate both sleep propensity and sleep inertia within a single recording session. The test allows each subject to act as his/her own control, thus increasing sensitivity. In the present series, it proved to be much more discriminative than waking ERPs alone to demonstrate specific abnormalities in patients complaining of excessive daytime

  2. Partial sleep deprivation by environmental noise increases food intake and body weight in obesity resistant rats

    OpenAIRE

    Mavanji, Vijayakumar; Teske, Jennifer A.; Billington, Charles J.; Kotz, Catherine M.

    2013-01-01

    Objective Sleep-restriction in humans increases risk for obesity, but previous rodent studies show weight loss following sleep deprivation, possibly due to stressful-methods used to prevent sleep. Obesity-resistant (OR) rats exhibit consolidated-sleep and resistance to weight-gain. We hypothesized that sleep disruption by a less-stressful method would increase body weight, and examined effect of partial sleep deprivation (PSD) on body weight in OR and Sprague-Dawley (SD) rats. Design and Meth...

  3. Refreshing Sleep and Sleep Continuity Determine Perceived Sleep Quality

    OpenAIRE

    Eva Libman; Catherine Fichten; Laura Creti; Kerry Conrod; Dieu-Ly Tran; Roland Grad; Mary Jorgensen; Rhonda Amsel; Dorrie Rizzo; Marc Baltzan; Alan Pavilanis; Sally Bailes

    2016-01-01

    Sleep quality is a construct often measured, employed as an outcome criterion for therapeutic success, but never defined. In two studies we examined appraised good and poor sleep quality in three groups: a control group, individuals with obstructive sleep apnea, and those with insomnia disorder. In Study 1 we used qualitative methodology to examine good and poor sleep quality in 121 individuals. In Study 2 we examined sleep quality in 171 individuals who had not participated in Study 1 and ev...

  4. Thermoregulatory effect in humans of suppressed endogenous melatonin by pre-sleep bright-light exposure in a cold environment.

    Science.gov (United States)

    Ishibashi, Keita; Arikura, Satoshi; Kozaki, Tomoaki; Higuchi, Shigekazu; Yasukouchi, Akira

    2010-06-01

    This study investigated the physiological function of suppressed melatonin through thermoregulation in a cold environment. Interactions between thermoregulation directly affected by exposure to a cold environment and indirectly affected by endogenous melatonin suppression by bright-light exposure were examined. Ten male subjects were exposed to two different illumination intensities (30 and 5000 lux) for 4.5 h, and two different ambient temperatures (15 and 27 degrees C) for 2 h before sleep under dark and thermoneutral conditions. Salivary melatonin level was suppressed by bright light (p cold ambient temperature (p cold exposure than thermoneutral conditions (cold: -0.54 +/- 0.07 degrees C/h; thermoneutral: -0.16 +/- 0.03 degrees C/h; p cold exposure masked the circadian rhythm with a precipitous decrease in T(re). A significant correlation between the T(re) nadir and melatonin level (r = -0.774, p cold exposure. These results suggest that suppressed endogenous melatonin inhibits the downregulation of the body temperature set-point during sleep.

  5. Melanin-concentrating hormone (MCH: a new sleep factor?

    Directory of Open Access Journals (Sweden)

    Pablo eTorterolo

    2011-03-01

    Full Text Available Neurons that utilize the neuropeptide melanin-concentrating hormone (MCH as a neuromodulator are mainly located in the lateral hypothalamus and the incerto-hypothalamic area, and have widespread projections throughout the brain. While the biological functions of this neuropeptide are exerted in humans through two metabotropic receptors, the MCHR1 and MCHR2, only the MCHR1 is present in rodents. Recently, it has been shown that the MCHergic system is involved in the control of sleep. We can summarize the experimental findings as follows:1. The areas related to the control of sleep and wakefulness have an important density of MCHergic fibers and receptors.2. MCHergic neurons are active during sleep, especially during REM sleep.3. Genetically-modified animals without MCH have less REM sleep, notably under conditions of negative energy balance. 4. Systemically administered MCHR1 antagonists reduce sleep. 5. Intraventricular microinjection of MCH increases both slow wave sleep (SWS and REM sleep; however, the increment in REM sleep is more pronounced.6. Microinjection of MCH into the dorsal raphe nucleus increases REM sleep time. REM seep is inhibited by immunoneutralization of MCH within this nucleus.7. Microinjection of MCH in the nucleus pontis oralis of the cat enhances REM sleep time and reduces REM sleep latency.All these data strongly suggest that MCH has a potent role in the promotion of sleep. Although both SWS and REM sleep are facilitated by MCH, REM sleep seems to be more sensitive to MCH modulation.

  6. Propensity Skor Agirliklandirma Yonteminde Denge Metriklerinin Performansi Uzerine Benzetim Calismasi

    Directory of Open Access Journals (Sweden)

    OSMAN DEMIR

    2017-09-01

    Full Text Available Objective: In the situation that randomization is not avaliable, to minimize the biasness in treatment arm assignments, the use of propensity score weighting method and the assessment of performances related to results obtained from generalized boosted and multinomial logistic regression (MLR of propensity score weighting are aimed. Method: Results obtained from MLR and GBM are to compare with the help of a simulation study. In simulation study, data with n=500, 1000, 2000 sample size will be derived using 1000 repetitions on seven scenarios with three categorized treatment group, continuous outcome variable and continuous/binary covariates. The propensity weights will be found with the help of Propensity scores obtained from MLR and GBM and using these weights, the balance will be assessed using balance metrics with average treatment effect estimation (ATE. In study, “twang” package in R program is used. Results: As the number of samples increases, the balance values decreases more, so it seems that the biasness has fallen. As the scenarios become more complex, GBM produces better balance results. There are better results for MLR at main effect model. Trimming or removing excess weights ensures improving of balance. [J Contemp Med 2017; 7(3.000: 265-277

  7. Analysis of consumers propensity towards foreign product: A survey ...

    African Journals Online (AJOL)

    This study is an empirical analysis of consumers' propensity to buy foreign goods, despite the fact that such goods are equally produced in domestic firms. The product that was taken into consideration was shoe. To elicit data for the study, questions were formulated and administered to 1412 respondents in Cross River and ...

  8. Lane-changing model with dynamic consideration of driver's propensity

    Science.gov (United States)

    Wang, Xiaoyuan; Wang, Jianqiang; Zhang, Jinglei; Ban, Xuegang Jeff

    2015-07-01

    Lane-changing is the driver's selection result of the satisfaction degree in different lane driving conditions. There are many different factors influencing lane-changing behavior, such as diversity, randomicity and difficulty of measurement. So it is hard to accurately reflect the uncertainty of drivers' lane-changing behavior. As a result, the research of lane-changing models is behind that of car-following models. Driver's propensity is her/his emotion state or the corresponding preference of a decision or action toward the real objective traffic situations under the influence of various dynamic factors. It represents the psychological characteristics of the driver in the process of vehicle operation and movement. It is an important factor to influence lane-changing. In this paper, dynamic recognition of driver's propensity is considered during simulation based on its time-varying discipline and the analysis of the driver's psycho-physic characteristics. The Analytic Hierarchy Process (AHP) method is used to quantify the hierarchy of driver's dynamic lane-changing decision-making process, especially the influence of the propensity. The model is validated using real data. Test results show that the developed lane-changing model with the dynamic consideration of a driver's time-varying propensity and the AHP method are feasible and with improved accuracy.

  9. Propensity for Voluntary Travel Behavior Changes: An Experimental Analysis

    DEFF Research Database (Denmark)

    Meloni, Italo; Sanjust, Benedetta; Sottile, Eleonora

    2013-01-01

    In this paper we analyze individual propensity to voluntary travel behavior change combining concepts from theory of change with the methodologies deriving from behavioral models. In particular, following the theory of voluntary changes, we set up a two-week panel survey including soft measure im...

  10. Learning and Propensity for Changing the Job Situation during Downsizing

    Science.gov (United States)

    Gustavsson, Maria

    2012-01-01

    Purpose: The purpose of this paper is to investigate individuals' learning and propensity for changing their job situation during downsizing in a company. Design/methodology/approach: A case study was carried out in an industrial company that had undergone major downsizing to adapt to changes in production. Approximately 100 employees retrained at…

  11. Maternal propensity for infections and risk of childhood asthma

    DEFF Research Database (Denmark)

    Stokholm, Jakob; Sevelsted, Astrid; Bønnelykke, Klaus

    2014-01-01

    antibiotic use is a surrogate marker of a mother's general propensity for infections as the underlying link between a mother's use of antibiotics and risk of asthma in the offspring. FUNDING: The Danish Council for Strategic Research, The Lundbeck Foundation, The Pharmacy Foundation of 1991, the Danish...... Medical Research Council, and National Finance Act....

  12. Propensity of Unqualified Audit Reports and Auditors' Independence ...

    African Journals Online (AJOL)

    First Lady

    2013-06-30

    Jun 30, 2013 ... the audit (McGrath, Siegel, Dunfee, Glazer and Jaenicke, 2004:39). The audit report communicates the auditor's findings to outsiders and plays a crucial role in warning financial statements users of impeding problems with the. Propensity of Unqualified Audit reports and Auditors‟ Independence in Nigeria ...

  13. Psychological Factors Predicting Risk-Taking Propensity of Poultry ...

    African Journals Online (AJOL)

    ... (Sd=10.70) were randomly selected among members of Poultry Farmers Association of Nigeria (POFAN), Ibadan Branch. Using a correlational design, the following measures were used: Performance Failure Appraisal Inventory (PFAI), Need for achievement scale, Locus of Control Behaviour and Risk-taking propensity.

  14. Propensity score matching and unmeasured covariate imbalance: A simulation study

    NARCIS (Netherlands)

    Ali, M. Sanni|info:eu-repo/dai/nl/345709497; Groenwold, Rolf H.H.; Belitser, Svetlana V.; Hoes, Arno W.; De Boer, A.|info:eu-repo/dai/nl/075097346; Klungel, Olaf H.|info:eu-repo/dai/nl/181447649

    2014-01-01

    Background: Selecting covariates for adjustment or inclusion in propensity score (PS) analysis is a trade-off between reducing confounding bias and a risk of amplifying residual bias by unmeasured confounders. Objectives: To assess the covariate balancing properties of PS matching with respect to

  15. One's sex, sleep, and posttraumatic stress disorder

    Directory of Open Access Journals (Sweden)

    Kobayashi Ihori

    2012-12-01

    Full Text Available Abstract Women are approximately twice as likely as men to develop posttraumatic stress disorder (PTSD after trauma exposure. Mechanisms underlying this difference are not well understood. Although sleep is recognized to have a critical role in PTSD and physical and psychological health more generally, research into the role of sleep in PTSD sex differences has been only recent. In this article, we review both animal and human studies relevant to sex differences in sleep and PTSD with an emphasis on the roles of sex hormones. Sleep impairment including insomnia, trauma-related nightmares, and rapid-eye-movement (REM sleep fragmentation has been observed in individuals with chronic and developing PTSD, suggesting that sleep impairment is a characteristic of PTSD and a risk factor for its development. Preliminary findings suggested sex specific patterns of sleep alterations in developing and established PTSD. Sleep maintenance impairment in the aftermath of trauma was observed in women who subsequently developed PTSD, and greater REM sleep fragmentation soon after trauma was associated with developing PTSD in both sexes. In chronic PTSD, reduced deep sleep has been found only in men, and impaired sleep initiation and maintenance with PTSD have been found in both sexes. A limited number of studies with small samples have shown that sex hormones and their fluctuations over the menstrual cycle influenced sleep as well as fear extinction, a process hypothesized to be critical to the pathogenesis of PTSD. To further elucidate the possible relationship between the sex specific patterns of PTSD-related sleep alterations and the sexually dimorphic risk for PTSD, future studies with larger samples should comprehensively examine effects of sex hormones and the menstrual cycle on sleep responses to trauma and the risk/resilience for PTSD utilizing various methodologies including fear conditioning and extinction paradigms and animal models.

  16. Post-combat invincibility: violent combat experiences are associated with increased risk-taking propensity following deployment.

    Science.gov (United States)

    Killgore, William D S; Cotting, Dave I; Thomas, Jeffrey L; Cox, Anthony L; McGurk, Dennis; Vo, Alexander H; Castro, Carl A; Hoge, Charles W

    2008-10-01

    Combat exposure is associated with increased rates of mental health problems such as post-traumatic stress disorder, depression, and anxiety when Soldiers return home. Another important health consequence of combat exposure involves the potential for increased risk-taking propensity and unsafe behavior among returning service members. Survey responses regarding 37 different combat experiences were collected from 1252 US Army Soldiers immediately upon return home from combat deployment during Operation Iraqi Freedom. A second survey that included the Evaluation of Risks Scale (EVAR) and questions about recent risky behavior was administered to these same Soldiers 3 months after the initial post-deployment survey. Combat experiences were reduced to seven factors using principal components analysis and used to predict post-deployment risk-propensity scores. Although effect sizes were small, specific combat experiences, including greater exposure to violent combat, killing another person, and contact with high levels of human trauma, were predictive of greater risk-taking propensity after homecoming. Greater exposure to these combat experiences was also predictive of actual risk-related behaviors in the preceding month, including more frequent and greater quantities of alcohol use and increased verbal and physical aggression toward others. Exposure to violent combat, human trauma, and having direct responsibility for taking the life of another person may alter an individual's perceived threshold of invincibility and slightly increase the propensity to engage in risky behavior upon returning home after wartime deployment. Findings highlight the importance of education and counseling for returning service members to mitigate the public health consequences of elevated risk-propensity associated with combat exposure.

  17. Effects of partial sleep deprivation on slow waves during non-rapid eye movement sleep: A high density EEG investigation.

    Science.gov (United States)

    Plante, David T; Goldstein, Michael R; Cook, Jesse D; Smith, Richard; Riedner, Brady A; Rumble, Meredith E; Jelenchick, Lauren; Roth, Andrea; Tononi, Giulio; Benca, Ruth M; Peterson, Michael J

    2016-02-01

    Changes in slow waves during non-rapid eye movement (NREM) sleep in response to acute total sleep deprivation are well-established measures of sleep homeostasis. This investigation utilized high-density electroencephalography (hdEEG) to examine topographic changes in slow waves during repeated partial sleep deprivation. Twenty-four participants underwent a 6-day sleep restriction protocol. Spectral and period-amplitude analyses of sleep hdEEG data were used to examine changes in slow wave energy, count, amplitude, and slope relative to baseline. Changes in slow wave energy were dependent on the quantity of NREM sleep utilized for analysis, with widespread increases during sleep restriction and recovery when comparing data from the first portion of the sleep period, but restricted to recovery sleep if the entire sleep episode was considered. Period-amplitude analysis was less dependent on the quantity of NREM sleep utilized, and demonstrated topographic changes in the count, amplitude, and distribution of slow waves, with frontal increases in slow wave amplitude, numbers of high-amplitude waves, and amplitude/slopes of low amplitude waves resulting from partial sleep deprivation. Topographic changes in slow waves occur across the course of partial sleep restriction and recovery. These results demonstrate a homeostatic response to partial sleep loss in humans. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  18. Effects of partial sleep deprivation on slow waves during non-rapid eye movement sleep: a high density EEG investigation

    Science.gov (United States)

    Plante, David T.; Goldstein, Michael R.; Cook, Jesse D.; Smith, Richard; Riedner, Brady A.; Rumble, Meredith E.; Jelenchick, Lauren; Roth, Andrea; Tononi, Giulio; Benca, Ruth M.; Peterson, Michael J.

    2015-01-01

    Objective Changes in slow waves during non-rapid eye movement (NREM) sleep in response to acute total sleep deprivation are well-established measures of sleep homeostasis. This investigation utilized high-density electroencephalography (hdEEG) to examine topographic changes in slow waves during repeated partial sleep deprivation. Methods Twenty-four participants underwent a 6-day sleep restriction protocol. Spectral and period-amplitude analyses of sleep hdEEG data were used to examine changes in slow wave energy, count, amplitude, and slope relative to baseline. Results Changes in slow wave energy were dependent on the quantity of NREM sleep utilized for analysis, with widespread increases during sleep restriction and recovery when comparing data from the first portion of the sleep period, but restricted to recovery sleep if the entire sleep episode was considered. Period-amplitude analysis was less dependent on the quantity of NREM sleep utilized, and demonstrated topographic changes in the count, amplitude, and distribution of slow waves, with frontal increases in slow wave amplitude, numbers of high-amplitude waves, and amplitude/slopes of low amplitude waves resulting from partial sleep deprivation. Conclusions Topographic changes in slow waves occur across the course of partial sleep restriction and recovery. Significance These results demonstrate a homeostatic response to partial sleep loss in humans. PMID:26596212

  19. Thermal environment and sleep in winter shelter-analogue settings

    Science.gov (United States)

    Mochizuki, Yosuke; Maeda, Kazuki; Nabeshima, Yuki; Tsuzuki, Kazuyo

    2017-10-01

    We aimed to examine sleep in shelter-analogue settings in winter to determine the sleep and environmental conditions in evacuation shelters. Twelve young healthy students took part in the sleep study of two nights for seven hours from 0 AM to 7 AM in a gymnasium. One night the subject used a pair of futons and on the other the subject used emergency supplies consisting of four blankets and a set of portable partitions. Air temperature, humidity were measured around the sleeping subjects through the night. Sleep parameters, skin temperature, microclimate temperature, rectal temperature, and heart rate of the subjects were continuously measured and recorded during the sleeping period. The subjects completed questionnaires relating to thermal comfort and subjective sleep before and after sleep. The sleep efficiency indices were lower when the subjects slept using the blankets. As the microclimate temperature between the human body and blanket was lower, mean skin temperature was significantly lower in the case of blankets.

  20. Time delay between cardiac and brain activity during sleep transitions

    Science.gov (United States)

    Long, Xi; Arends, Johan B.; Aarts, Ronald M.; Haakma, Reinder; Fonseca, Pedro; Rolink, Jérôme

    2015-04-01

    Human sleep consists of wake, rapid-eye-movement (REM) sleep, and non-REM (NREM) sleep that includes light and deep sleep stages. This work investigated the time delay between changes of cardiac and brain activity for sleep transitions. Here, the brain activity was quantified by electroencephalographic (EEG) mean frequency and the cardiac parameters included heart rate, standard deviation of heartbeat intervals, and their low- and high-frequency spectral powers. Using a cross-correlation analysis, we found that the cardiac variations during wake-sleep and NREM sleep transitions preceded the EEG changes by 1-3 min but this was not the case for REM sleep transitions. These important findings can be further used to predict the onset and ending of some sleep stages in an early manner.

  1. Trait impulsive choice predicts resistance to extinction and propensity to relapse to cocaine seeking: a bidirectional investigation.

    Science.gov (United States)

    Broos, Nienke; Diergaarde, Leontien; Schoffelmeer, Anton Nm; Pattij, Tommy; De Vries, Taco J

    2012-05-01

    Despite the strong association between impulsivity and addiction in humans, it is still a matter of debate whether impulsive choice predisposes to, or results from, drug dependence. Furthermore, it is unknown whether treating impulsivity can protect against relapse propensity. Therefore, this study explored the bidirectional relationship between impulsive choice and cocaine taking and seeking in rat behavioral models. In experiment 1, to determine whether impulsive choice predisposes to cocaine taking or seeking, rats were selected based on trait impulsivity in a delayed reward task and subsequently compared on various stages of cocaine self-administration (SA). To examine the consequence of cocaine intake on impulsive choice, impulsivity was monitored once a week throughout various stages of cocaine SA. To determine whether treating impulsive choice can protect against relapse propensity, in experiment 2, impulsive choice was manipulated by pharmacological interventions and cocaine-associated contextual cues. Trait impulsive choice as determined in experiment 1 predicted high extinction resistance and enhanced propensity to context-induced relapse in the cocaine SA model, whereas cocaine intake did not alter impulsive choice. Furthermore, acute changes in impulsive choice were not related to rates of context-induced relapse. Taken together, the current data indicate that trait impulsive choice predicts persistent cocaine seeking during extinction and enhanced propensity to relapse, whereas acute manipulations of impulsive choice had no favorable outcomes on relapse measures. These observations suggest that trait impulsivity can be used as a predictive factor for addiction liability, but treating this impulsivity does not necessarily protect against relapse.

  2. Trait Impulsive Choice Predicts Resistance to Extinction and Propensity to Relapse to Cocaine Seeking: A Bidirectional Investigation

    Science.gov (United States)

    Broos, Nienke; Diergaarde, Leontien; Schoffelmeer, Anton NM; Pattij, Tommy; De Vries, Taco J

    2012-01-01

    Despite the strong association between impulsivity and addiction in humans, it is still a matter of debate whether impulsive choice predisposes to, or results from, drug dependence. Furthermore, it is unknown whether treating impulsivity can protect against relapse propensity. Therefore, this study explored the bidirectional relationship between impulsive choice and cocaine taking and seeking in rat behavioral models. In experiment 1, to determine whether impulsive choice predisposes to cocaine taking or seeking, rats were selected based on trait impulsivity in a delayed reward task and subsequently compared on various stages of cocaine self-administration (SA). To examine the consequence of cocaine intake on impulsive choice, impulsivity was monitored once a week throughout various stages of cocaine SA. To determine whether treating impulsive choice can protect against relapse propensity, in experiment 2, impulsive choice was manipulated by pharmacological interventions and cocaine-associated contextual cues. Trait impulsive choice as determined in experiment 1 predicted high extinction resistance and enhanced propensity to context-induced relapse in the cocaine SA model, whereas cocaine intake did not alter impulsive choice. Furthermore, acute changes in impulsive choice were not related to rates of context-induced relapse. Taken together, the current data indicate that trait impulsive choice predicts persistent cocaine seeking during extinction and enhanced propensity to relapse, whereas acute manipulations of impulsive choice had no favorable outcomes on relapse measures. These observations suggest that trait impulsivity can be used as a predictive factor for addiction liability, but treating this impulsivity does not necessarily protect against relapse. PMID:22318198

  3. Effects of sustained sleep restriction on mitogen-stimulated cytokines, chemokines and T helper 1/ T helper 2 balance in humans.

    Directory of Open Access Journals (Sweden)

    John Axelsson

    Full Text Available BACKGROUND: Recent studies suggest that acute sleep deprivation disrupts cellular immune responses by shifting T helper (Th cell activity towards a Th2 cytokine profile. Since little is known about more long-term effects, we investigated how five days of sleep restriction would affect pro-inflammatory, chemotactic, Th1- and Th2 cytokine secretion. METHODS: Nine healthy males participated in an experimental sleep protocol with two baseline sleep-wake cycles (sleep 23.00-07.00 h followed by 5 days with restricted sleep (03.00-07.00 h. On the second baseline day and on the fifth day with restricted sleep, samples were drawn every third hour for determination of cytokines/chemokines (tumor necrosis factor alpha (TNF-α, interleukin (IL -1β, IL-2, IL-4 and monocyte chemoattractant protein-1 (MCP-1 after in vitro stimulation of whole blood samples with the mitogen phytohemagglutinin (PHA. Also leukocyte numbers, mononuclear cells and cortisol were analysed. RESULTS: 5-days of sleep restriction affected PHA-induced immune responses in several ways. There was a general decrease of IL-2 production (p<.05. A shift in Th1/Th2 cytokine balance was also evident, as determined by a decrease in IL2/IL4 ratio. No other main effects of restricted sleep were shown. Two significant interactions showed that restricted sleep resulted in increased TNF-α and MCP-1 in the late evening and early night hours (p's<.05. In addition, all variables varied across the 24 h day. CONCLUSIONS: 5-days of sleep restriction is characterized by a shift towards Th2 activity (i.e. lower 1L-2/IL-4 ratio which is similar to the effects of acute sleep deprivation and psychological stress. This may have implications for people suffering from conditions characterized by excessive Th2 activity like in allergic disease, such as asthma, for whom restricted sleep could have negative consequences.

  4. Sleep health of healthcare workers in Kano, Nigeria | Kolo | Nigerian ...

    African Journals Online (AJOL)

    Background: The relevance of sleep in the life of a human being cannot be overemphasized in terms of physical and mental well-being. Among several factors that can affect the sleep health of an individual occupation have been found to play a prominent role. The literature is still scanty with regard to sleep studies in our ...

  5. Sleep disturbance associated factors in menopausal women

    Directory of Open Access Journals (Sweden)

    Hamid Haghani

    2011-09-01

    Full Text Available Background: Sleep is necessary in life and approximately 1/3 of human life is devoted to sleep. One of the most common problems in menopausal women is sleep disturbance. The aim of this study was to determine frequency of sleep disorders and its related factors in 50 – 60 years old women Methods: A cross-sectional, descriptive study was conducted on 200 eligible women who referred to selected health centers of Tehran University of Medical Sciences (TUMS. Demographic form, ten-point slide to review sexual satisfaction and Pittsburg Sleep Quality Index Questioner (PSQI were used for data collection. Data was analyzed using ANOVA, t-test, and Pearson correlation tests.Results: The mean age of women was 53.6±3.6 year, menopause age 47.8±4, number of children 4.76±2 and partner age was 57.99±6.6. 34.5% of women were satisfied from their sexual relationship and their score was 8-10. Rate of sleep disturbances in this group was about 70%. The results showed that between four variables: economical status, occupation, partner occupation and educational status were significantly associated with sleep disturbance (P=0.002. There was not significant difference between other demographic information and sleep disturbance.Conclusion: The results show high prevalence of sleep disturbance symptoms among menopausal women. According to the relationship between some personal characters and sleep disturbance, health care providers need to consider these variables.

  6. Sleep after Learning Aids Memory Recall

    Science.gov (United States)

    Born, Jan; Gais, Steffen; Lucas, Brian

    2006-01-01

    In recent years, the effect of sleep on memory consolidation has received considerable attention. In humans, these studies concentrated mainly on procedural types of memory, which are considered to be hippocampus-independent. Here, we show that sleep also has a persisting effect on hippocampus-dependent declarative memory. In two experiments, we…

  7. Regular Sleep Makes for Happier College Students

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_166856.html Regular Sleep Makes for Happier College Students When erratic snoozers improve shut-eye habits, ... Health and Human Services. More Health News on College Health Healthy Sleep Recent Health News Related MedlinePlus Health Topics College ...

  8. Sleep patterns and sleep disturbances across pregnancy.

    Science.gov (United States)

    Mindell, Jodi A; Cook, Rae Ann; Nikolovski, Janeta

    2015-04-01

    This study sought to characterize sleep patterns and sleep problems in a large sample of women across all months of pregnancy. A total of 2427 women completed an Internet-based survey that included the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, vitality scale of the Short Form 36 Health Survey (SF-36), Insomnia Severity Index (ISI), Berlin questionnaire, International Restless Legs Syndrome (IRLS) question set, and a short version of the Pregnancy Symptoms Inventory (PSI). Across all months of pregnancy, women experienced poor sleep quality (76%), insufficient nighttime sleep (38%), and significant daytime sleepiness (49%). All women reported frequent nighttime awakenings (100%), and most women took daytime naps (78%). Symptoms of insomnia (57%), sleep-disordered breathing (19%), and restless legs syndrome (24%) were commonly endorsed, with no difference across the month of pregnancy for insomnia, sleep-disorder breathing, daytime sleepiness, or fatigue. In addition, high rates of pregnancy-related symptoms were found to disturb sleep, especially frequent urination (83%) and difficulty finding a comfortable sleep position (79%). Women experience significant sleep disruption, inadequate sleep, and high rates of symptoms of sleep disorder throughout pregnancy. These results suggest that all women should be screened and treated for sleep disturbances throughout pregnancy, especially given the impact of inadequate sleep and sleep disorders on fetal, pregnancy, and postpartum outcomes. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Unsupervised online classifier in sleep scoring for sleep deprivation studies.

    Science.gov (United States)

    Libourel, Paul-Antoine; Corneyllie, Alexandra; Luppi, Pierre-Hervé; Chouvet, Guy; Gervasoni, Damien

    2015-05-01

    This study was designed to evaluate an unsupervised adaptive algorithm for real-time detection of sleep and wake states in rodents. We designed a Bayesian classifier that automatically extracts electroencephalogram (EEG) and electromyogram (EMG) features and categorizes non-overlapping 5-s epochs into one of the three major sleep and wake states without any human supervision. This sleep-scoring algorithm is coupled online with a new device to perform selective paradoxical sleep deprivation (PSD). Controlled laboratory settings for chronic polygraphic sleep recordings and selective PSD. Ten adult Sprague-Dawley rats instrumented for chronic polysomnographic recordings. The performance of the algorithm is evaluated by comparison with the score obtained by a human expert reader. Online detection of PS is then validated with a PSD protocol with duration of 72 hours. Our algorithm gave a high concordance with human scoring with an average κ coefficient > 70%. Notably, the specificity to detect PS reached 92%. Selective PSD using real-time detection of PS strongly reduced PS amounts, leaving only brief PS bouts necessary for the detection of PS in EEG and EMG signals (4.7 ± 0.7% over 72 h, versus 8.9 ± 0.5% in baseline), and was followed by a significant PS rebound (23.3 ± 3.3% over 150 minutes). Our fully unsupervised data-driven algorithm overcomes some limitations of the other automated methods such as the selection of representative descriptors or threshold settings. When used online and coupled with our sleep deprivation device, it represents a better option for selective PSD than other methods like the tedious gentle handling or the platform method. © 2015 Associated Professional Sleep Societies, LLC.

  10. The Role of Sleep in Changing Our Minds: A Psychologist's Discussion of Papers on Memory Reactivation and Consolidation in Sleep

    Science.gov (United States)

    Cartwright, Rosalind D.

    2004-01-01

    The group of papers on memory reactivation and consolidation during sleep included in this volume represents cutting edge work in both animals and humans. They support that the two types of sleep serve different necessary functions. The role of slow wave sleep (SWS) is reactivation of the hippocampal-neocortical circuits activated during a waking…

  11. Mobile phones and sleep - A review

    Science.gov (United States)

    Supe, Sanjay S.

    2010-01-01

    The increasing use of mobile phones has raised concerns regarding the potential health effects of exposure to the radiofrequency electromagnetic fields. An increasing amount research related to mobile phone use has focussed on the possible effects of mobile phone exposure on human brain activity and function. In particular, the use of sleep research has become a more widely used technique for assessing the possible effects of mobile phones on human health and wellbeing especially in the investigation of potential changes in sleep architecture resulting from mobile phone use. Acute exposure to a mobile phone prior to sleep significantly enhances electroencephalogram spectral power in the sleep spindle frequency range. This mobile phone-induced enhancement in spectral power is largely transitory and does not linger throughout the night. Furthermore, a reduction in rapid eye movement sleep latency following mobile phone exposure was also found, although interestingly, neither this change in rapid eye movement sleep latency or the enhancement in spectral power following mobile phone exposure, led to changes in the overall quality of sleep. In conclusion, a short exposure to the radiofrequency electromagnetic fields emitted by a mobile phone handset immediately prior to sleep is sufficient to induce changes in brain activity in the initial part of sleep. The consequences or functional significance of this effect are currently unknown and it would be premature to draw conclusions about possible health consequences.

  12. Improved Mental Acuity Forecasting with an Individualized Quantitative Sleep Model

    OpenAIRE

    Winslow, Brent D.; Nam Nguyen; Venta, Kimberly E.

    2017-01-01

    Sleep impairment significantly alters human brain structure and cognitive function, but available evidence suggests that adults in developed nations are sleeping less. A growing body of research has sought to use sleep to forecast cognitive performance by modeling the relationship between the two, but has generally focused on vigilance rather than other cognitive constructs affected by sleep, such as reaction time, executive function, and working memory. Previous modeling efforts have also ut...

  13. Effects of sleep deprivation on neural functioning: an integrative review

    OpenAIRE

    Boonstra, T.W.; Stins, J. F.; Daffertshofer, A; Beek, P. J.

    2007-01-01

    Abstract. Sleep deprivation has a broad variety of effects on human performance and neural functioning that manifest themselves at different levels of description. On a macroscopic level, sleep deprivation mainly affects executive functions, especially in novel tasks. Macroscopic and mesoscopic effects of sleep deprivation on brain activity include reduced cortical responsiveness to incoming stimuli, reflecting reduced attention. On a microscopic level, sleep deprivation is associated with in...

  14. Total sleep deprivation decreases flow experience and mood status

    OpenAIRE

    Kaida K; Niki K

    2013-01-01

    Kosuke Kaida, Kazuhisa NikiHuman Technology Research Institute, National Institute of Advanced Industrial Science and Technology, Ibaraki, JapanBackground: The purpose of this study was to examine the effect of sleep deprivation on flow experience.Methods: Sixteen healthy male volunteers of mean age 21.4±1.59 (21–24) years participated in two experimental conditions, ie, sleep-deprivation and normal sleep. In the sleep-deprived condition, participants stayed awake at home...

  15. Bed-sharing and co-sleeping : research overview.

    OpenAIRE

    Ball, Helen L.

    2009-01-01

    This review examines the issue of babies sleeping with their parents. Beginning with an anthropological perspective, the biological underpinnings of parent-baby sleep contact are explored, as are crosscultural practices. The relationship between baby sleeping and feeding practices in the UK is considered along with the safety aspects of bed-sharing. Key points: • Parent-baby sleep contact is a predictable human behaviour based on our species’ evolutionary ...

  16. Age-Related Reduction of Recovery Sleep and Arousal Threshold in Drosophila

    Science.gov (United States)

    Vienne, Julie; Spann, Ryanne; Guo, Fang; Rosbash, Michael

    2016-01-01

    Study Objectives: Physiological studies show that aging affects both sleep quality and quantity in humans, and sleep complaints increase with age. Along with knowledge about the negative effects of poor sleep on health, understanding the enigmatic relationship between sleep and aging is important. Because human sleep is similar to Drosophila (fruit fly) sleep in many ways, we addressed the effects of aging on sleep in this model organism. Methods: Baseline sleep was recorded in five different Drosophila genotypes raised at either 21°C or 25°C. The amount of sleep recovered was then investigated after a nighttime of sleep deprivation (12 h) and after chronic sleep deprivation (3 h every night for multiple nights). Finally, the effects of aging on arousal, namely, sensitivity to neuronal and mechanical stimuli, were studied. Results: We show that fly sleep is affected by age in a manner similar to that of humans and other mammals. Not only do older flies of several genotypes have more fragmented sleep and reduced total sleep time compared to young flies, but older flies also fail to recover as much sleep after sleep deprivation. This suggests either lower sleep homeostasis and/or a failure to properly recover sleep. Older flies also show a decreased arousal threshold, i.e., an increased response to neuronal and mechanical wake-promoting stimuli. The reduced threshold may either reflect or cause the reduced recovery sleep of older flies compared to young flies after sleep deprivation. Conclusions: Further studies are certainly needed, but we suggest that the lower homeostatic sleep drive of older flies causes their decreased arousal threshold. Citation: Vienne J, Spann R, Guo F, Rosbash M. Age-related reduction of recovery sleep and arousal threshold in Drosophila. SLEEP 2016;39(8):1613–1624. PMID:27306274

  17. Sleep characteristics in children with growth hormone deficiency.

    Science.gov (United States)

    Verrillo, Elisabetta; Bizzarri, Carla; Cappa, Marco; Bruni, Oliviero; Pavone, Martino; Ferri, Raffaele; Cutrera, Renato

    2011-01-01

    Growth hormone (GH) is preferentially secreted during slow wave sleep and the interactions between human sleep and the somatotropic system are well documented, although only few studies have investigated the sleep EEG in children with GH deficiency (GHD). The aim of this study was to evaluate the sleep structure of children with dysregulation of the GH/insulin-like growth factor axis. Laboratory polysomnographic sleep recordings were obtained from 10 GHD children and 20 normal healthy age-matched children. The classical sleep parameters were evaluated together with sleep microstructure, by means of the cyclic alternating pattern (CAP), in GHD patients and compared to the control group. GHD children showed a significant decrease in total sleep time, sleep efficiency, movement time and in non-rapid eye movement sleep stage 2. Although some indicators of sleep fragmentation were increased in GHD children, we found a general decrease in EEG arousability represented by a significant global decrease in the CAP rate, involving all CAP A phase subtypes. The analysis of sleep microstructure by means of CAP, in children with GHD, showed a reduction of transient EEG amplitude oscillations. Further studies are needed in order to better clarify whether GH therapy is able to modify sleep microstructure in GHD children, and the relationships between sleep microstructure, hormonal secretion and neurocognitive function in these patients. Copyright © 2011 S. Karger AG, Basel.

  18. Cues of fatigue: effects of sleep deprivation on facial appearance.

    Science.gov (United States)

    Sundelin, Tina; Lekander, Mats; Kecklund, Göran; Van Someren, Eus J W; Olsson, Andreas; Axelsson, John

    2013-09-01

    To investigate the facial cues by which one recognizes that someone is sleep deprived versus not sleep deprived. Experimental laboratory study. Karolinska Institutet, Stockholm, Sweden. Forty observers (20 women, mean age 25 ± 5 y) rated 20 facial photographs with respect to fatigue, 10 facial cues, and sadness. The stimulus material consisted of 10 individuals (five women) photographed at 14:30 after normal sleep and after 31 h of sleep deprivation following a night with 5 h of sleep. Ratings of fatigue, fatigue-related cues, and sadness in facial photographs. The faces of sleep deprived individuals were perceived as having more hanging eyelids, redder eyes, more swollen eyes, darker circles under the eyes, paler skin, more wrinkles/fine lines, and more droopy corners of the mouth (effects ranging from b = +3 ± 1 to b = +15 ± 1 mm on 100-mm visual analog scales, P sleep deprivation (P sleep deprivation, nor associated with judgements of fatigue. In addition, sleep-deprived individuals looked sadder than after normal sleep, and sadness was related to looking fatigued (P sleep deprivation affects features relating to the eyes, mouth, and skin, and that these features function as cues of sleep loss to other people. Because these facial regions are important in the communication between humans, facial cues of sleep deprivation and fatigue may carry social consequences for the sleep deprived individual in everyday life.

  19. Is sleep deprivation a contributor to obesity in children?

    Science.gov (United States)

    Chaput, Jean-Philippe

    2016-03-01

    Chronic lack of sleep (called "sleep deprivation") is common in modern societies with 24/7 availability of commodities. Accumulating evidence supports the role of reduced sleep as contributing to the current obesity epidemic in children and youth. Longitudinal studies have consistently shown that short sleep duration is associated with weight gain and the development of obesity. Recent experimental studies have reported that sleep restriction leads to weight gain in humans. Increased food intake appears to be the main mechanism by which insufficient sleep results in weight gain. Voluntary sleep restriction has been shown to increase snacking, the number of meals eaten per day, and the preference for energy-dense foods. Although the causes of sleep loss in the pediatric population are numerous, more research looking at screen exposure before bedtime and its effects on sleep is needed given the pervasiveness of electronic media devices in today's environment. Health professionals should routinely ask questions about sleep and promote a good night's sleep because insufficient sleep impacts activity and eating behaviors. Future research should examine the clinical benefits of increasing sleep duration on eating behaviors and body weight control and determine the importance of adequate sleep to improve the treatment of obesity.

  20. Role of sleep timing in caloric intake and BMI.

    Science.gov (United States)

    Baron, Kelly G; Reid, Kathryn J; Kern, Andrew S; Zee, Phyllis C

    2011-07-01

    Sleep duration has been linked to obesity and there is also an emerging literature in animals demonstrating a relationship between the timing of feeding and weight regulation. However, there is a paucity of research evaluating timing of sleep and feeding on weight regulation in humans. The goal of this study was to evaluate the role of sleep timing in dietary patterns and BMI. Participants included 52 (25 females) volunteers who completed 7 days of wrist actigraphy and food logs. Fifty-six percent were "normal sleepers" (midpoint of sleep ≥5:30 AM). Late sleepers had shorter sleep duration, later sleep onset and sleep offset and meal times. Late sleepers consumed more calories at dinner and after 8:00 PM, had higher fast food, full-calorie soda and lower fruit and vegetable consumption. Higher BMI was associated with shorter sleep duration, later sleep timing, caloric consumption after 8:00 PM, and fast food meals. In multivariate models, sleep timing was independently associated with calories consumed after 8:00 PM and fruit and vegetable consumption but did not predict BMI after controlling for sleep duration. Calories consumed after 8:00 PM predicted BMI after controlling for sleep timing and duration. These findings indicate that caloric intake after 8:00 PM may increase the risk of obesity, independent of sleep timing and duration. Future studies should investigate the biological and social mechanisms linking timing of sleep and feeding in order to develop novel time-based interventions for weight management.

  1. Sleep duration is affected by social relationships among sleeping partners in wild Japanese macaques.

    Science.gov (United States)

    Mochida, Koji; Nishikawa, Mari

    2014-03-01

    Co-sleeping behaviour, such as sharing a sleeping site or bed, should play an important role in determining sleep structure in mammals by mitigating predation pressure and harsh abiotic conditions during sleep. Although environmental factors surrounding sleeping sites have been studied, there is very little information on the effects of the social environment within the site on sleep in animals other than humans. Here, we quantified the duration of nighttime sleep of wild primates during behavioural observations. Wild Japanese macaques (Macaca fuscata yakui) form clusters at sleeping sites, where they huddle with group members. Macaques slept for longer when huddled in sleeping clusters with natal members than in those with non-natal members. A high degree of synchronisation of wakefulness in pairs of macaques huddling in non-natal clusters suggested that their sleep was often interrupted by the wakefulness of huddling members at night. Our results suggest that familiarity and closeness to huddling partners influence sleep duration. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Adolescent changes in the homeostatic and circadian regulation of sleep.

    Science.gov (United States)

    Hagenauer, M H; Perryman, J I; Lee, T M; Carskadon, M A

    2009-01-01

    Sleep deprivation among adolescents is epidemic. We argue that this sleep deprivation is due in part to pubertal changes in the homeostatic and circadian regulation of sleep. These changes promote a delayed sleep phase that is exacerbated by evening light exposure and incompatible with aspects of modern society, notably early school start times. In this review of human and animal literature, we demonstrate that delayed sleep phase during puberty is likely a common phenomenon in mammals, not specific to human adolescents, and we provide insight into the mechanisms underlying this phenomenon.

  3. [Impact of sleep debt on physiological rhythms].

    Science.gov (United States)

    Spiegel, K; Leproult, R; Van Cauter, E

    2003-11-01

    Sleep loss due to voluntary bedtime curtailment has become a hallmark of modern society. Even though sleep deprivation in rodents has been shown to result in death, it was until a few years ago thought that sleep loss results in increased sleepiness and decreased cognitive performance but has little or no adverse effects on human health. We measured sleep and 24-hour hormonal profiles in 11 healthy young males after 6 days of sleep restriction (4-hour bedtime) and after 6 days of sleep recovery (12-hour bedtime). At the end of sleep restriction, we observed reduced amounts of slow wave sleep (SWS) and rapid eye movement (REM) sleep and an alteration in the temporal distribution of these sleep stages, i.e. an increased pressure for REM sleep at the beginning of the sleep period and a decrease in the amount of slow wave activity (SWA) during the first sleep cycle. These later abnormalities are usually observed in depression. In addition, numerous alterations in the 24-hour hormonal profiles were observed in the state of sleep debt. The amount of melatonin secreted was reduced because of a delay in the onset of the nocturnal secretion and a reduction in the value of the acrophase. If the overall 24-hour cortisol profile was preserved, sleep restriction was associated with increased cortisol levels in late afternoon and evening hours and the duration of the quiescent period was reduced. The 24-hour mean TSH levels were reduced and the nocturnal TSH elevation was markedly dampened, most likely as a result of elevated levels of thyroid hormones. The acrophase of the 24-hour leptin profile occurred earlier, the amplitude of the rhythm and the overall mean levels were reduced. The nocturnal elevation of prolactin levels was abrupt but of short duration and the 24-hour mean levels were decreased. A pulse of growth hormone occurred prior to sleep onset, therefore affecting SWA distribution at the beginning of the sleep period. Since these alterations are qualitatively and

  4. The role of sleep in changing our minds: A psychologist's discussion of papers on memory reactivation and consolidation in sleep

    OpenAIRE

    Cartwright, Rosalind D.

    2004-01-01

    The group of papers on memory reactivation and consolidation during sleep included in this volume represents cutting edge work in both animals and humans. They support that the two types of sleep serve different necessary functions. The role of slow wave sleep (SWS) is reactivation of the hippocampal-neocortical circuits activated during a waking learning period, while REM sleep is responsible for the consolidation of this new learning into long-term memory. These studies provide further insi...

  5. Strategies for Getting Enough Sleep

    Science.gov (United States)

    ... the NHLBI on Twitter. Strategies for Getting Enough Sleep You can take steps to improve your sleep ... Rate This Content: NEXT >> Updated: June 7, 2017 Sleep Infographic Sleep Disorders & Insufficient Sleep: Improving Health through ...

  6. Sleep Fragmentation Exacerbates Mechanical Hypersensitivity and Alters Subsequent Sleep-Wake Behavior in a Mouse Model of Musculoskeletal Sensitization

    Science.gov (United States)

    Sutton, Blair C.; Opp, Mark R.

    2014-01-01

    Study Objectives: Sleep deprivation, or sleep disruption, enhances pain in human subjects. Chronic musculoskeletal pain is prevalent in our society, and constitutes a tremendous public health burden. Although preclinical models of neuropathic and inflammatory pain demonstrate effects on sleep, few studies focus on musculoskeletal pain. We reported elsewhere in this issue of SLEEP that musculoskeletal sensitization alters sleep of mice. In this study we hypothesize that sleep fragmentation during the development of musculoskeletal sensitization will exacerbate subsequent pain responses and alter sleep-wake behavior of mice. Design: This is a preclinical study using C57BL/6J mice to determine the effect on behavioral outcomes of sleep fragmentation combined with musculoskeletal sensitization. Methods: Musculoskeletal sensitization, a model of chronic muscle pain, was induced using two unilateral injections of acidified saline (pH 4.0) into the gastrocnemius muscle, spaced 5 days apart. Musculoskeletal sensitization manifests as mechanical hypersensitivity determined by von Frey filament testing at the hindpaws. Sleep fragmentation took place during the consecutive 12-h light periods of the 5 days between intramuscular injections. Electroencephalogram (EEG) and body temperature were recorded from some mice at baseline and for 3 weeks after musculoskeletal sensitization. Mechanical hypersensitivity was determined at preinjection baseline and on days 1, 3, 7, 14, and 21 after sensitization. Two additional experiments were conducted to determine the independent effects of sleep fragmentation or musculoskeletal sensitization on mechanical hypersensitivity. Results: Five days of sleep fragmentation alone did not induce mechanical hypersensitivity, whereas sleep fragmentation combined with musculoskeletal sensitization resulted in prolonged and exacerbated mechanical hypersensitivity. Sleep fragmentation combined with musculoskeletal sensitization had an effect on

  7. Sleep deprivation and daily torpor impair object recognition in Djungarian hamsters

    NARCIS (Netherlands)

    Palchykova, S; Crestani, F; Meerlo, P; Tobler, Irene

    2006-01-01

    Sleep has been shown to play a facilitating role in memory consolidation, whereas sleep deprivation leads to performance impairment both in humans and rodents. The effects of 4-h sleep deprivation on recognition memory were investigated in the Djungarian hamster (Phodopus sungorus). Because sleep

  8. Electroencephalogram Power Density and Slow Wave Sleep as a Function of Prior Waking and Circadian Phase

    NARCIS (Netherlands)

    Dijk, Derk-Jan; Brunner, Daniel P.; Beersma, Domien G.M.; Borbély, Alexander A.

    1990-01-01

    Human sleep electroencephalograms, recorded in four experiments, were subjected to spectral analysis. Waking prior to sleep varied from 12 to 36 h and sleep was initiated at different circadian phases. Power density of delta and theta frequencies in rapid-eye-movement (REM) sleep and non-REM (NREM)

  9. Snoring and Sleep Apnea

    Science.gov (United States)

    ... dentist, or oral surgeon with expertise in sleep dentistry. In some patients, significant weight loss can also ... Link: Treatment Options for Adults with Snoring Link: Pediatric Sleep Disordered Breathing/Obstructive Sleep Apnea Link: Pediatric ...

  10. Side Effects: Sleep Problems

    Science.gov (United States)

    Sleep problems are a common side effect during cancer treatment. Learn how a polysomnogram can assess sleep problems. Learn about the benefits of managing sleep disorders in men and women with cancer.

  11. Sleep and Chronic Disease

    Science.gov (United States)

    ... Search The CDC Cancel Submit Search The CDC Sleep and Sleep Disorders Note: Javascript is disabled or is not ... Data Source Projects and Partners Resources For Clinicians Sleep and Chronic Disease Recommend on Facebook Tweet Share ...

  12. Sleep and your health

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000871.htm Sleep and your health To use the sharing features ... in a number of ways. Why You Need Sleep Sleep gives your body and brain time to ...

  13. Sleep Apnea Information Page

    Science.gov (United States)

    ... Page You are here Home » Disorders » All Disorders Sleep Apnea Information Page Sleep Apnea Information Page What research is being done? ... Institutes of Health (NIH) conduct research related to sleep apnea in laboratories at the NIH, and also ...

  14. Sleep and Newborns

    Science.gov (United States)

    ... of Braces Eating Disorders Mitral Valve Prolapse Arrhythmias Sleep and Newborns KidsHealth > For Parents > Sleep and Newborns ... night it is. How Long Will My Newborn Sleep? Newborns should get 14 to 17 hours of ...

  15. Sleep paralysis and psychopathology

    African Journals Online (AJOL)

    hypnagogic paralysis) or from sleep to wakefulness. (hypnopompic paralysis). It is considered to be a parasomnia related to rapid eye movement (REM) sleep because it tends to occur during awakenings from REM sleep and its pathophysiology.

  16. Irregular sleep (image)

    Science.gov (United States)

    ... sleep and wakefulness which disrupt the normal daily sleep-wake cycle. It may be caused by brain dysfunction or not following a normal sleep schedule, ultimately leading to a pattern of insomnia ...

  17. What Is Sleep Apnea?

    Science.gov (United States)

    ... have type 2 diabetes. Hormonal changes in sleep deprivation. We know that sleep deprivation decreases the response of the body to insulin , ... with sleep apnea who finds it hard to use your CPAP machine? This study is assessing whether ...

  18. Brain Basics: Understanding Sleep

    Science.gov (United States)

    ... and more deeply after a period of sleep deprivation. Factors that influence your sleep-wake needs include ... noise, produce light that stimulates melatonin production, and use gentle vibrations to help us sleep and wake. ...

  19. Influence of polyvinylpyrrolidone on aggregation propensity of coated spheroids.

    Science.gov (United States)

    Wong, T; Heng, P; Yeo, T; Chan, L

    2002-08-21

    The influence of polyvinylpyrrolidone (PVP), a commonly used binder and adhesive, on the aggregation of spheroids coated with hydroxypropylmethylcellulose (HPMC) was studied. The aggregation propensities of spheroids coated by HPMC alone and by HPMC with polyethylene glycol (PEG) were compared with those coated by HPMC with PVP and the viscosity of the coating solutions determined. The coating was conducted at a maximum spray rate of 11 g/min to avoid premature termination of the coating process at higher spray rates due to uncontrollable aggregation of spheroids. PVP was able to reduce the extent of aggregation of spheroids. It was more effective in reducing spheroid aggregation than PEG. The reduction in spheroid aggregation propensity was ascribed to viscosity lowering effects of PVP. The viscosity of the coating solutions determined over the temperature range of 28-58 degrees C was found to increase in the following order: HPMC-PVP

  20. Psychological vulnerabilities and propensities for involvement in violent extremism.

    Science.gov (United States)

    Borum, Randy

    2014-01-01

    Research on the psychology of terrorism has argued against the idea that most terrorist behavior is caused by mental illness or by a terrorist personality. This article suggests an alternative line of inquiry - an individual psychology of terrorism that explores how otherwise normal mental states and processes, built on characteristic attitudes, dispositions, inclinations, and intentions, might affect a person's propensity for involvement with violent extremist groups and actions. It uses the concepts of "mindset" - a relatively enduring set of attitudes, dispositions, and inclinations - and worldview as the basis of a psychological "climate," within which various vulnerabilities and propensities shape ideas and behaviors in ways that can increase the person's risk or likelihood of involvement in violent extremism. Copyright © 2014 John Wiley & Sons, Ltd.

  1. Statin use and kidney cancer outcomes: A propensity score analysis.

    Science.gov (United States)

    Nayan, Madhur; Finelli, Antonio; Jewett, Michael A S; Juurlink, David N; Austin, Peter C; Kulkarni, Girish S; Hamilton, Robert J

    2016-11-01

    Studies evaluating the association between statin use and survival outcomes in renal cell carcinoma have demonstrated conflicting results. Our objective was to evaluate this association in a large clinical cohort by using propensity score methods to reduce confounding from measured covariates. We performed a retrospective review of 893 patients undergoing nephrectomy for unilateral, M0 renal cell carcinoma between 2000 and 2014 at a tertiary academic center. Inverse probability of treatment weights were derived from a propensity score model based on clinical, surgical, and pathological characteristics. We used Cox proportional hazard models to evaluate the association between statin use and disease-free survival, cancer-specific survival, and overall survival in the sample weighted by the inverse probability of treatment weights. A secondary analysis was performed matching statin users 1:1 to statin nonusers on the propensity score. Of the 893 patients, 259 (29%) were on statins at the time of surgery. Median follow-up was 47 months (interquartile range: 20-80). Statin use was not significantly associated with disease-free survival (hazard ratio [HR] = 1.09, 95% CI: 0.65-1.81), cancer-specific survival (HR = 0.90, 95% CI: 0.40-2.01), or overall survival (HR = 0.89, 95% CI: 0.55-1.44). Similar results were observed when using propensity score matching. The present study found no significant association between statin use and kidney cancer outcomes. Population-based studies are needed to further evaluate the role of statins in kidney cancer therapy. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Analysis of EEG activity during sleep - brain hemisphere symmetry of two classes of sleep spindles

    Science.gov (United States)

    Smolen, Magdalena M.

    2009-01-01

    This paper presents automatic analysis of some selected human electroencephalographic patterns during deep sleep using the Matching Pursuit (MP) algorithm. The periodicity of deep sleep EEG patterns was observed by calculating autocorrelation functions of their percentage contributions. The study confirmed the increasing trend of amplitude-weighted average frequency of sleep spindles from frontal to posterior derivations. The dominant frequencies from the left and the right brain hemisphere were strongly correlated.

  3. Slow wave and REM sleep deprivation effects on explicit and implicit memory during sleep.

    OpenAIRE

    Casey, Sarah; Solomons, Luke C.; Steier, Joerg Sebastian; Kabra, Neeraj; Burnside, Anna; Pengo, Martino F; Moxham, John; Goldstein, Laura Hilary; Kopelman, M D

    2016-01-01

    Objective: It has been debated whether different stages in the human sleep cycle preferentially mediate the consolidation of explicit and implicit memories, or whether all of the stages in succession are necessary for optimal consolidation. Here we investigated whether the selective deprivation of slow wave sleep (SWS) or rapid eye movement (REM) sleep over an entire night would have a specific effect on consolidation in explicit and implicit memory tasks. Method: Participants completed a set...

  4. Sleep Medicine Textbook

    OpenAIRE

    Bassetti, Claudio; Dogas, Zoran; Peigneux, Philippe

    2014-01-01

    The Sleep Medicine Textbook provides comprehensive, all-in-one educational material (550 pages) structured around the Catalogue of knowledge and skills for sleep medicine (Penzel et al. 2014, Journal of Sleep Research). Written by experts in the field and published by the ESRS, it provides an European approach to sleep medicine education, and represents the knowledge-base for the ESRS-endorsed sleep medicine examinations.The book is available at http://www.esrs.eu/esrs/sleep-medicine-textbook...

  5. Irregular sleep/wake patterns are associated with poorer academic performance and delayed circadian and sleep/wake timing.

    Science.gov (United States)

    Phillips, Andrew J K; Clerx, William M; O'Brien, Conor S; Sano, Akane; Barger, Laura K; Picard, Rosalind W; Lockley, Steven W; Klerman, Elizabeth B; Czeisler, Charles A

    2017-06-12

    The association of irregular sleep schedules with circadian timing and academic performance has not been systematically examined. We studied 61 undergraduates for 30 days using sleep diaries, and quantified sleep regularity using a novel metric, the sleep regularity index (SRI). In the most and least regular quintiles, circadian phase and light exposure were assessed using salivary dim-light melatonin onset (DLMO) and wrist-worn photometry, respectively. DLMO occurred later (00:08 ± 1:54 vs. 21:32 ± 1:48; p sleep propensity rhythm peaked later (06:33 ± 0:19 vs. 04:45 ± 0:11; p academic performance and SRI was observed. These findings show that irregular sleep and light exposure patterns in college students are associated with delayed circadian rhythms and lower academic performance. Moreover, the modeling results reveal that light-based interventions may be therapeutically effective in improving sleep regularity in this population.

  6. An Examination of the Developmental Propensity Model of Conduct Problems

    Science.gov (United States)

    Rhee, Soo Hyun; Friedman, Naomi P.; Corley, Robin P.; Hewitt, John K.; Hink, Laura K.; Johnson, Daniel P.; Watts, Ashley K. Smith; Young, Susan E.; Robinson, JoAnn; Waldman, Irwin D.; Zahn-Waxler, Carolyn

    2015-01-01

    The present study tested specific hypotheses advanced by the developmental propensity model of the etiology of conduct problems in the Colorado Longitudinal Twin Study, a prospective, longitudinal, genetically informative sample. High negative emotionality, low behavioral inhibition, low concern and high disregard for others, and low cognitive ability assessed during toddlerhood (age 14 to 36 months) were examined as predictors of conduct problems in later childhood and adolescence (age 4 to 17 years). Each hypothesized antisocial propensity dimension predicted conduct problems, but some predictions may be context specific or due to method covariance. The most robust predictors were observed disregard for others (i.e., responding to others’ distress with active, negative responses such as anger and hostility), general cognitive ability, and language ability, which were associated with conduct problems reported by parents, teachers, and adolescents, and change in observed negative emotionality (i.e., frustration tolerance), which was associated with conduct problems reported by teachers and adolescents. Furthermore, associations between the most robust early predictors and later conduct problems were influenced by the shared environment rather than genes. We conclude that shared environmental influences that promote disregard for others and detract from cognitive and language development during toddlerhood also predispose individuals to conduct problems in later childhood and adolescence. The identification of those shared environmental influences common to early antisocial propensity and later conduct problems is an important future direction, and additional developmental behavior genetic studies examining the interaction between children’s characteristics and socializing influences on conduct problems are needed. PMID:26653135

  7. Dynamics of Sleep Stage Transitions in Health and Disease

    Science.gov (United States)

    Kishi, Akifumi; Struzik, Zbigniew R.; Natelson, Benjamin H.; Togo, Fumiharu; Yamamoto, Yoshiharu

    2007-07-01

    Sleep dynamics emerges from complex interactions between neuronal populations in many brain regions. Annotated sleep stages from electroencephalography (EEG) recordings could potentially provide a non-invasive way to obtain valuable insights into the mechanisms of these interactions, and ultimately into the very nature of sleep regulation. However, to date, sleep stage analysis has been restricted, only very recently expanding the scope of the traditional descriptive statistics to more dynamical concepts of the duration of and transitions between vigilance states and temporal evaluation of transition probabilities among different stages. Physiological and/or pathological implications of the dynamics of sleep stage transitions have, to date, not been investigated. Here, we study detailed duration and transition statistics among sleep stages in healthy humans and patients with chronic fatigue syndrome, known to be associated with disturbed sleep. We find that the durations of waking and non-REM sleep, in particular deep sleep (Stages III and IV), during the nighttime, follow a power-law probability distribution function, while REM sleep durations follow an exponential function, suggestive of complex underlying mechanisms governing the onset of light sleep. We also find a substantial number of REM to non-REM transitions in humans, while this transition is reported to be virtually non-existent in rats. Interestingly, the probability of this REM to non-REM transition is significantly lower in the patients than in controls, resulting in a significantly greater REM to awake, together with Stage I to awake, transition probability. This might potentially account for the reported poor sleep quality in the patients because the normal continuation of sleep after either the lightest or REM sleep is disrupted. We conclude that the dynamical transition analysis of sleep stages is useful for elucidating yet-to-be-determined human sleep regulation mechanisms with a

  8. The distracted mind on the wheel: Overall propensity to mind wandering is associated with road crash responsibility.

    Directory of Open Access Journals (Sweden)

    Cédric Gil-Jardiné

    Full Text Available The role of distractions on attentional lapses that place road users in higher risk of crash remains poorly understood. We aimed to assess the respective impact of (i mind wandering trait (propensity to mind wander in the everyday life as measured with a set of 4 questions on the proportion of time spent mind wandering in 4 different situations and (ii mind wandering state (disturbing thoughts just before the crash on road crash risk using a comparison between responsible and non-responsible drivers. 954 drivers injured in a road crash were interviewed at the adult emergency department of the Bordeaux university hospital in France (2013-2015. Responsibility for the crash, mind wandering (trait/state, external distraction, alcohol use, psychotropic drug use, and sleep deprivation were evaluated. Based on questionnaire reports, 39% of respondents were classified with a mind wandering trait and 13% reported a disturbing thought just before the crash. While strongly correlated, mind wandering state and trait were independently associated with responsibility for a traffic crash (State: OR = 2.51, 95% CI: 1.64-3.83 and Trait: OR = 1.62, 95% CI: 1.22-2.16 respectively. Self-report of distracting thoughts therefore did not capture the entire risk associated with the propensity of the mind to wander, either because of under-reported thoughts and/or other deleterious mechanisms to be further explored.

  9. Biomechanical properties of the human upper airway and their effect on its behavior during breathing and in obstructive sleep apnea.

    Science.gov (United States)

    Bilston, Lynne E; Gandevia, Simon C

    2014-02-01

    The upper airway is a complex, multifunctional, dynamic neuromechanical system. Its patency during breathing requires moment-to-moment coordination of neural and mechanical behavior and varies with posture. Failure to continuously recruit and coordinate dilator muscles to counterbalance the forces that act to close the airway results in hypopneas or apneas. Repeated failures lead to obstructive sleep apnea (OSA). Obesity and anatomical variations, such as retrognathia, increase the likelihood of upper airway collapse by altering the passive mechanical behavior of the upper airway. This behavior depends on the mechanical properties of each upper airway tissue in isolation, their geometrical arrangements, and their physiological interactions. Recent measurements of respiratory-related deformation of the airway wall have shown that there are different patterns of airway soft tissue movement during the respiratory cycle. In OSA patients, airway dilation appears less coordinated compared with that in healthy subjects (matched for body mass index). Intrinsic mechanical properties of airway tissues are altered in OSA patients, but the factors underlying these changes have yet to be elucidated. How neural drive to the airway dilators relates to the biomechanical behavior of the upper airway (movement and stiffness) is still poorly understood. Recent studies have highlighted that the biomechanical behavior of the upper airway cannot be simply predicted from electromyographic activity (electromyogram) of its muscles.

  10. Sleep Disturbances in Depression.

    Science.gov (United States)

    Murphy, Michael J; Peterson, Michael J

    2015-03-01

    Major depressive disorder is frequently accompanied by sleep disturbances such as insomnia or hypersomnia and polysomnographic sleep findings of increased rapid-eye-movement sleep and decreased slow wave sleep. For many patients, insomnia persists even after mood symptoms have been adequately treated. These patients have poorer outcomes than patients without sleep problems. These outcomes suggest that overlapping neural mechanisms regulate sleep and mood. Treatment of these patients can incorporate sedating antidepressants, nonbenzodiazepine γ-aminobutyric acid agonists, and cognitive behavioral therapy. Sleep restriction has been found to improve mood in depressed patients; however, the benefits typically disappear after recovery sleep. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Age-Related Reduction of Recovery Sleep and Arousal Threshold in Drosophila.

    Science.gov (United States)

    Vienne, Julie; Spann, Ryanne; Guo, Fang; Rosbash, Michael

    2016-08-01

    Physiological studies show that aging affects both sleep quality and quantity in humans, and sleep complaints increase with age. Along with knowledge about the negative effects of poor sleep on health, understanding the enigmatic relationship between sleep and aging is important. Because human sleep is similar to Drosophila (fruit fly) sleep in many ways, we addressed the effects of aging on sleep in this model organism. Baseline sleep was recorded in five different Drosophila genotypes raised at either 21°C or 25°C. The amount of sleep recovered was then investigated after a nighttime of sleep deprivation (12 h) and after chronic sleep deprivation (3 h every night for multiple nights). Finally, the effects of aging on arousal, namely, sensitivity to neuronal and mechanical stimuli, were studied. We show that fly sleep is affected by age in a manner similar to that of humans and other mammals. Not only do older flies of several genotypes have more fragmented sleep and reduced total sleep time compared to young flies, but older flies also fail to recover as much sleep after sleep deprivation. This suggests either lower sleep homeostasis and/or a failure to properly recover sleep. Older flies also show a decreased arousal threshold, i.e., an increased response to neuronal and mechanical wake-promoting stimuli. The reduced threshold may either reflect or cause the reduced recovery sleep of older flies compared to young flies after sleep deprivation. Further studies are certainly needed, but we suggest that the lower homeostatic sleep drive of older flies causes their decreased arousal threshold. © 2016 Associated Professional Sleep Societies, LLC.

  12. Effects of daytime food intake on memory consolidation during sleep or sleep deprivation.

    Directory of Open Access Journals (Sweden)

    Nina Herzog

    Full Text Available Sleep enhances memory consolidation. Bearing in mind that food intake produces many metabolic signals that can influence memory processing in humans (e.g., insulin, the present study addressed the question as to whether the enhancing effect of sleep on memory consolidation is affected by the amount of energy consumed during the preceding daytime. Compared to sleep, nocturnal wakefulness has been shown to impair memory consolidation in humans. Thus, a second question was to examine whether the impaired memory consolidation associated with sleep deprivation (SD could be compensated by increased daytime energy consumption. To these aims, 14 healthy normal-weight men learned a finger tapping sequence (procedural memory and a list of semantically associated word pairs (declarative memory. After the learning period, standardized meals were administered, equaling either ∼50% or ∼150% of the estimated daily energy expenditure. In the morning, after sleep or wakefulness, memory consolidation was tested. Plasma glucose was measured both before learning and retrieval. Polysomnographic sleep recordings were performed by electroencephalography (EEG. Independent of energy intake, subjects recalled significantly more word pairs after sleep than they did after SD. When subjects stayed awake and received an energy oversupply, the number of correctly recalled finger sequences was equal to those seen after sleep. Plasma glucose did not differ among conditions, and sleep time in the sleep conditions was not influenced by the energy intake interventions. These data indicate that the daytime energy intake level affects neither sleep's capacity to boost the consolidation of declarative and procedural memories, nor sleep's quality. However, high energy intake was followed by an improved procedural but not declarative memory consolidation under conditions of SD. This suggests that the formation of procedural memory is not only triggered by sleep but is also

  13. Effects of daytime food intake on memory consolidation during sleep or sleep deprivation.

    Science.gov (United States)

    Herzog, Nina; Friedrich, Alexia; Fujita, Naoko; Gais, Steffen; Jauch-Chara, Kamila; Oltmanns, Kerstin M; Benedict, Christian

    2012-01-01

    Sleep enhances memory consolidation. Bearing in mind that food intake produces many metabolic signals that can influence memory processing in humans (e.g., insulin), the present study addressed the question as to whether the enhancing effect of sleep on memory consolidation is affected by the amount of energy consumed during the preceding daytime. Compared to sleep, nocturnal wakefulness has been shown to impair memory consolidation in humans. Thus, a second question was to examine whether the impaired memory consolidation associated with sleep deprivation (SD) could be compensated by increased daytime energy consumption. To these aims, 14 healthy normal-weight men learned a finger tapping sequence (procedural memory) and a list of semantically associated word pairs (declarative memory). After the learning period, standardized meals were administered, equaling either ∼50% or ∼150% of the estimated daily energy expenditure. In the morning, after sleep or wakefulness, memory consolidation was tested. Plasma glucose was measured both before learning and retrieval. Polysomnographic sleep recordings were performed by electroencephalography (EEG). Independent of energy intake, subjects recalled significantly more word pairs after sleep than they did after SD. When subjects stayed awake and received an energy oversupply, the number of correctly recalled finger sequences was equal to those seen after sleep. Plasma glucose did not differ among conditions, and sleep time in the sleep conditions was not influenced by the energy intake interventions. These data indicate that the daytime energy intake level affects neither sleep's capacity to boost the consolidation of declarative and procedural memories, nor sleep's quality. However, high energy intake was followed by an improved procedural but not declarative memory consolidation under conditions of SD. This suggests that the formation of procedural memory is not only triggered by sleep but is also sensitive to the

  14. Executive Risk Propensity and Accounting Conservatism Through the Lens of Life History Theory

    DEFF Research Database (Denmark)

    Holm, Morten; Schneider, Melanie L.

    First, we intend to investigate the impact of CFO risk propensity on accounting conservatism. Second, we will examine the role of CEOs in this context. By drawing on life history theory, we propose variables reflecting executive risk propensity. Based on this, we hypothesize that CFO risk...... propensity is negatively associated with accounting conservatism. Additionally, we hypothesize that CEO risk propensity exerts a moderating effect on this association. To test our hypotheses, we will conduct multivariate analyses based on a sample of Danish panel data. By utilizing innovative proxies...... for risk propensity, we intend to expand research on executives´ influence on accounting conservatism (Francis et al. [2015])....

  15. Medical Imaging for Understanding Sleep Regulation

    Science.gov (United States)

    Wong, Kenneth

    2011-10-01

    Sleep is essential for the health of the nervous system. Lack of sleep has a profound negative effect on cognitive ability and task performance. During sustained military operations, soldiers often suffer from decreased quality and quantity of sleep, increasing their susceptibility to neurological problems and limiting their ability to perform the challenging mental tasks that their missions require. In the civilian sector, inadequate sleep and overt sleep pathology are becoming more common, with many detrimental impacts. There is a strong need for new, in vivo studies of human brains during sleep, particularly the initial descent from wakefulness. Our research team is investigating sleep using a combination of magnetic resonance imaging (MRI), positron emission tomography (PET), and electroencephalography (EEG). High resolution MRI combined with PET enables localization of biochemical processes (e.g., metabolism) to anatomical structures. MRI methods can also be used to examine functional connectivity among brain regions. Neural networks are dynamically reordered during different sleep stages, reflecting the disconnect with the waking world and the essential yet unconscious brain activity that occurs during sleep.[4pt] In collaboration with Linda Larson-Prior, Washington University; Alpay Ozcan, Virginia Tech; Seong Mun, Virginia Tech; and Zang-Hee Cho, Gachon University.

  16. Autoimmune rheumatic disease and sleep: a review.

    Science.gov (United States)

    Sangle, Shirish R; Tench, Colin M; D'Cruz, David P

    2015-11-01

    Sleep has an important role to play in the human immune system and it is critical in the restoration and maintenance of homeostasis. Sleep deprivation and disorders may have a profound impact on health, well being and the ability to resist infection. Autoimmune rheumatic diseases are multisystem disorders that involve complicated hormonal and immunological pathophysiology. Previous studies have suggested that sleep deprivation may lead to immunological disturbance in experimental mouse models. Sleep disorders may trigger immune system abnormalities inducing autoantibody production, possibly leading to the development of autoimmune disease such as systemic lupus erythematosus, scleroderma or rheumatoid arthritis. Indeed, in experimental models, it has been suggested that sleep deprivation may induce the onset of autoimmune disease. Chronic deprivation of sleep is common in modern society and has been seen in various autoimmune inflammatory rheumatic diseases. We have reviewed various aspects of sleep deprivation and sleep apnoea syndrome, and their effects on the immune system and their relevance to autoimmune diseases. We hope that these data will encourage greater awareness of the role that improved sleep hygiene may play in the management of these rheumatic diseases.

  17. Mobile phones and sleep - A review

    National Research Council Canada - National Science Library

    Supe, Sanjay S

    2010-01-01

    .... In particular, the use of sleep research has become a more widely used technique for assessing the possible effects of mobile phones on human health and wellbeing especially in the investigation...

  18. Altered sleep-wake cycles and physical performance in athletes.

    Science.gov (United States)

    Reilly, Thomas; Edwards, Ben

    2007-02-28

    Sleep-waking cycles are fundamental in human circadian rhythms and their disruption can have consequences for behaviour and performance. Such disturbances occur due to domestic or occupational schedules that do not permit normal sleep quotas, rapid travel across multiple meridians and extreme athletic and recreational endeavours where sleep is restricted or totally deprived. There are methodological issues in quantifying the physiological and performance consequences of alterations in the sleep-wake cycle if the effects on circadian rhythms are to be separated from the fatigue process. Individual requirements for sleep show large variations but chronic reduction in sleep can lead to immuno-suppression. There are still unanswered questions about the sleep needs of athletes, the role of 'power naps' and the potential for exercise in improving the quality of sleep.

  19. CHILDREN NUTRITION AND SLEEP: IS THERE A CONNECTION?

    Directory of Open Access Journals (Sweden)

    S. G. Gribakin

    2014-01-01

    Full Text Available Human and especially children sleep is an important and complicated physiological phenomenon. The questions of the nature of sleep are studied by a relatively new field of science — somnology. The quality of sleep influences behavioral reactions as well as cognitive functions. Profound studies of sleep phenomenon were started in the middle of the 20th century. Formation of diurnal rhythm of sleep and wakefulness takes place in children during the first months of life. It is established that certain nutrients (tryptophan and serotonin, which are the sources of melatonin, complex carbohydrates, long-chain polyunsaturated fatty acids etc. along with external factors participate in development of circadian rhythms of sleep and wakefulness. Those nutrients which can influence on formation of sleep/wakefulness rhythms were named «chrononutrients». The article describes the methods of sleep characteristics study in children and influence of certain nutrients on these characteristics.

  20. A new function of rapid eye movement sleep: improvement of muscular efficiency.

    Science.gov (United States)

    Cai, Zi-Jian

    2015-05-15

    Previously I demonstrated that the slow wave sleep (SWS) functioned to adjust the emotional balance disrupted by emotional memories randomly accumulated during waking, while the rapid eye movement (REM) sleep played the opposite role. Many experimental results have unambiguously shown that various emotional memories are processed during REM sleep. In this article, it is attempted to combine this confirmed function of REM sleep with the atonic state unique to REM sleep, and to integrate a new theory suggesting that improvement of muscular efficiency be a new function of REM sleep. This new function of REM sleep is more advantageous than the function of REM sleep in emotional memories and disinhibited drives to account for the phylogenetic variations of REM sleep, especially the absence of REM sleep in dolphins and short duration of REM sleep in birds in contrary to that in humans and rodents, the absence of penile erections in REM sleep in armadillo, as well as the higher voltage in EEG during REM sleep in platypus and ostrich. Besides, this new function of REM sleep is also advantageous to explain the association of REM sleep with the atonic episodes in SWS, the absence of drastic menopausal change in duration of REM sleep, and the effects of ambient temperature on the duration of REM sleep. These comparative and experimental evidences support the improvement of muscular efficiency as a new and major function of REM sleep. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Sleep: A Health Imperative

    Science.gov (United States)

    Luyster, Faith S.; Strollo, Patrick J.; Zee, Phyllis C.; Walsh, James K.

    2012-01-01

    Chronic sleep deficiency, defined as a state of inadequate or mistimed sleep, is a growing and underappreciated determinant of health status. Sleep deprivation contributes to a number of molecular, immune, and neural changes that play a role in disease development, independent of primary sleep disorders. These changes in biological processes in response to chronic sleep deficiency may serve as etiological factors for the development and exacerbation of cardiovascular and metabolic diseases and, ultimately, a shortened lifespan. Sleep deprivation also results in significant impairments in cognitive and motor performance which increase the risk of motor vehicle crashes and work-related injuries and fatal accidents. The American Academy of Sleep Medicine and the Sleep Research Society have developed this statement to communicate to national health stakeholders the current knowledge which ties sufficient sleep and circadian alignment in adults to health. Citation: Luyster FS; Strollo PJ; Zee PC; Walsh JK. Sleep: a health imperative. SLEEP 2012;35(6):727-734. PMID:22654183

  2. College residential sleep environment.

    Science.gov (United States)

    Sexton-Radek, Kathy; Hartley, Andrew

    2013-12-01

    College students regularly report increased sleep disturbances as well as concomitant reductions in performance (e.g., academic grades) upon entering college. Sleep hygiene refers to healthy sleep practices that are commonly used as first interventions in sleep disturbances. One widely used practice of this sort involves arranging the sleep environment to minimize disturbances from excessive noise and light at bedtime. Communal sleep situations such as those in college residence halls do not easily support this intervention. Following several focus groups, a questionnaire was designed to gather self-reported information on sleep disturbances in a college population. The present study used The Young Adult Sleep Environment Inventory (YASEI) and sleep logs to investigate the sleep environment of college students living in residential halls. A summary of responses indicated that noise and light are significant sleep disturbances in these environments. Recommendations are presented related to these findings.

  3. Brain-specific interleukin-1 receptor accessory protein in sleep regulation.

    Science.gov (United States)

    Taishi, Ping; Davis, Christopher J; Bayomy, Omar; Zielinski, Mark R; Liao, Fan; Clinton, James M; Smith, Dirk E; Krueger, James M

    2012-03-01

    Interleukin (IL)-1β is involved in several brain functions, including sleep regulation. It promotes non-rapid eye movement (NREM) sleep via the IL-1 type I receptor. IL-1β/IL-1 receptor complex signaling requires adaptor proteins, e.g., the IL-1 receptor brain-specific accessory protein (AcPb). We have cloned and characterized rat AcPb, which shares substantial homologies with mouse AcPb and, compared with AcP, is preferentially expressed in the brain. Furthermore, rat somatosensory cortex AcPb mRNA varied across the day with sleep propensity, increased after sleep deprivation, and was induced by somnogenic doses of IL-1β. Duration of NREM sleep was slightly shorter and duration of REM sleep was slightly longer in AcPb knockout than wild-type mice. In response to lipopolysaccharide, which is used to induce IL-1β, sleep responses were exaggerated in AcPb knockout mice, suggesting that, in normal mice, inflammation-mediated sleep responses are attenuated by AcPb. We conclude that AcPb has a role in sleep responses to inflammatory stimuli and, possibly, in physiological sleep regulation.

  4. Sleep disorders in pregnancy

    Directory of Open Access Journals (Sweden)

    Lopes Eliane Aversa

    2004-01-01

    Full Text Available CONTEXT: The precise function of sleep in animals and human beings is still unknown, and any sort of physical, social or psychological variation may change the normal sleep-wake cycle. PURPOSE: This research aims is to determine the sleep disorders (SD for each of the three trimesters of the pregnancy comparing them to the pre-pregnancy state (PG. METHOD: SD were investigated in three hundred pregnant women 11- to 40-years-old through with a brief clinical interview based on directed questions. One hundred pregnant women were considered for each trimester. RESULTS: The rate of pregnant women with insomnia increased by 23% in the 2nd trimester (p< 0.005; the rate for excessive daytime sleepiness (EDS by 15% in the 1st trimester (p<0.003, 55% in the 2nd trimester (p<0.001 and by 14% in the 3rd trimester (p<0.002; the rate for mild sleepiness increased by 33% in the 2nd trimester (p<0.002 and by 48% in the 3rd trimester (p<0.001; the rate for specific awakenings increased by 63% in the 1st trimester, by 80% in the 2nd trimester and by 84% in the 3rd trimester (p<0.001. CONCLUSION: SD were more frequent during pregnancy comparatively to PG state, mostly at the expenses of EDS and specific awakenings.

  5. Loneliness is associated with sleep fragmentation in a communal society.

    Science.gov (United States)

    Kurina, Lianne M; Knutson, Kristen L; Hawkley, Louise C; Cacioppo, John T; Lauderdale, Diane S; Ober, Carole

    2011-11-01

    Loneliness has been shown to predict poor health. One hypothesized mechanism is that lonely individuals do not sleep as well as individuals who feel more connected to others. Our goal was to test whether loneliness is associated with sleep fragmentation or sleep duration. Cross-sectional study. Members of a traditional, communal, agrarian society living in South Dakota. Ninety-five participants (mean age 39.8 years, 55% female) who were ≥ 19 years of age at the study's inception. Not applicable. We conducted interviews querying loneliness, depression, anxiety, and stress, as well as subjective sleep quality and daytime sleepiness. Study participants wore a wrist actigraph for one week to measure objective sleep properties; the two studied here were sleep fragmentation and sleep duration. Higher loneliness scores were associated with significantly higher levels of sleep fragmentation (β = 0.073, t = 2.55, P = 0.01), controlling for age, sex, body mass index, risk of sleep apnea, and negative affect (a factor comprising symptoms of depression and anxiety, and perceived stress). Loneliness was not associated with sleep duration or with either subjective sleep measure. Loneliness was a significant predictor of sleep fragmentation. Humans' social nature may partly be manifest through our dependence on feeling secure in our social environment to sleep well.

  6. [The neurobiology of sleep and its influence on memory].

    Science.gov (United States)

    Ertuğrul, Aygün; Rezaki, Murat

    2004-01-01

    Recent developments in neuroscience have increased our knowledge of the physiology of sleep and dreaming, and thus the number of studies about the influence of sleep on learning and memory have increased rapidly. In this review the objective is to assess the relationship between sleep and memory considering the evidence regarding the neurobiology of sleep and dreaming. This is a retrospective literature review and the relevant studies from the l