Sleep Deprivation (sleep + deprivation)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Paradoxical Sleep Deprivation and Sleep Recovery: Effects on the Hypothalamic,Pituitary,Adrenal Axis Activity, Energy Balance and Body Composition of Rats

JOURNAL OF NEUROENDOCRINOLOGY, Issue 4 2006
D. C. Hipólide
Abstract Numerous studies indicate that sleep deprivation alters energy expenditure. However, this conclusion is drawn from indirect measurements. In the present study, we investigated alterations of energy expenditure, body composition, blood glucose levels, plasma insulin, adrenocorticotropic hormone (ACTH) and corticosterone levels immediately after 4 days of sleep deprivation or after 4 days of sleep recovery. Rats were sleep deprived or maintained in a control environment (groups sleep-deprived/deprivation and control/deprivation). One half of these animals were sacrificed at the end of the deprivation period and the other half was transported to metabolic cages, where they were allowed to sleep freely (groups sleep-deprived/recovery and control/recovery). At the end of the sleep recovery period, these rats were sacrificed. After sleep deprivation, sleep-deprived rats exhibited loss of body weight, augmented energy expenditure and reduced metabolic efficiency compared to control rats. These alterations were normalised during the sleep recovery period. The body composition of sleep-deprived rats was altered insofar as there was a loss of fat content and gain of protein content in the carcass compared to control rats. However, these alterations were not reversed by sleep recovery. Finally, plasma levels of insulin were reduced during the sleep deprivation period in both control and sleep deprived groups compared to the recovery period. After the deprivation period, plasma ACTH and corticosterone levels were increased in sleep-deprived rats compared to control rats, and although ACTH levels were similar between the groups after the sleep recovery period, corticosterone levels remained elevated in sleep-deprived rats after this period. By means of direct measurements of metabolism, our results showed that sleep deprivation produces increased energy expenditure and loss of fat content. Most of the alterations were reversed by sleep recovery, except for corticosterone levels and body composition. [source]


Development and implementation of a noise reduction intervention programme: a pre- and postaudit of three hospital wards

JOURNAL OF CLINICAL NURSING, Issue 23 2009
Annette Richardson
Aims., By developing, implementing and delivering a noise reduction intervention programme, we aimed to attempt to reduce the high noise levels on inpatient wards. Background., Sleep is essential for human survival and sleep deprivation is detrimental to health and well being. Exposure to noise has been found to disrupt sleep in hospitalised patients which is to be expected as noise levels have been measured and reported as high. Design., A primarily nursing focused, multi-method approach, involving development of clinical guidelines, ward environment review and a staff noise awareness and education programme, was used to target mainly nursing staff plus other healthcare staff on three wards within one hospital. Methods., This practice development initiative was carried out in three key phases (1) Preaudit of ward noise levels, (2) The development, implementation and delivery of a noise reduction intervention programme, (3) Postaudit of ward noise levels. Results., Preintervention average peak decibel levels over 24 hours were found to be 96·48 dB(A) and postintervention average peak decibel levels were measured at 77·52 dB(A), representing an overall significant reduction in noise levels (p < 0·001). Conclusions., This study describes one way to reduce peak noise levels on inpatient hospital wards. Relevance to clinical practice., Sleep deprivation is detrimental to patients with acute illness, so any developments to improve patients' sleep are important. Nurses have a key role in leading, developing and implementing changes to reduce peak noise levels on inpatient wards in hospitals. This nurse-led practice development programme has demonstrated how improvements can be achieved by significantly reducing peak noise levels using simple multi-method change strategies. [source]


The effects of one night of sleep deprivation on known-risk and ambiguous-risk decisions

JOURNAL OF SLEEP RESEARCH, Issue 3 2007
BENJAMIN S. MCKENNA
Summary Sleep deprivation has been shown to alter decision-making abilities. The majority of research has utilized fairly complex tasks with the goal of emulating 'real-life' scenarios. Here, we use a Lottery Choice Task (LCT) which assesses risk and ambiguity preference for both decisions involving potential gains and those involving potential losses. We hypothesized that one night of sleep deprivation would make subjects more risk seeking in both gains and losses. Both a control group and an experimental group took the LCT on two consecutive days, with an intervening night of either sleep or sleep deprivation. The control group demonstrated that there was no effect of repeated administration of the LCT. For the experimental group, results showed significant interactions of night (normal sleep versus total sleep deprivation, TSD) by frame (gains versus losses), which demonstrate that following as little as 23 h of TSD, the prototypical response to decisions involving risk is altered. Following TSD, subjects were willing to take more risk than they ordinarily would when they were considering a gain, but less risk than they ordinarily would when they were considering a loss. For ambiguity preferences, there seems to be no direct effect of TSD. These findings suggest that, overall, risk preference is moderated by TSD, but whether an individual is willing to take more or less risk than when well-rested depends on whether the decision is framed in terms of gains or losses. [source]


Impaired decision making following 49 h of sleep deprivation

JOURNAL OF SLEEP RESEARCH, Issue 1 2006
WILLIAM D. S. KILLGORE
Summary Sleep deprivation reduces regional cerebral metabolism within the prefrontal cortex, the brain region most responsible for higher-order cognitive processes, including judgment and decision making. Accordingly, we hypothesized that two nights of sleep loss would impair decision making quality and lead to increased risk-taking behavior on the Iowa Gambling Task (IGT), which mimics real-world decision making under conditions of uncertainty. Thirty-four healthy participants completed the IGT at rested baseline and again following 49.5 h of sleep deprivation. At baseline, volunteers performed in a manner similar to that seen in most samples of healthy normal individuals, rapidly learning to avoid high-risk decks and selecting more frequently from advantageous low-risk decks as the game progressed. After sleep loss, however, volunteers showed a strikingly different pattern of performance. Relative to rested baseline, sleep-deprived individuals tended to choose more frequently from risky decks as the game progressed, a pattern similar to, though less severe than, previously published reports of patients with lesions to the ventromedial prefrontal cortex. Although risky decision making was not related to participant age when tested at rested baseline, age was negatively correlated with advantageous decision making on the IGT, when tested following sleep deprivation (i.e. older subjects made more risky choices). These findings suggest that cognitive functions known to be mediated by the ventromedial prefrontal cortex, including decision making under conditions of uncertainty, may be particularly vulnerable to sleep loss and that this vulnerability may become more pronounced with increased age. [source]


Effects of sleep deprivation on wound healing

JOURNAL OF SLEEP RESEARCH, Issue 3 2005
L. MOSTAGHIMI
Summary Sleep deprivation is widely regarded as a stressor and has been shown to have significant effects on host defences. Severely sleep-deprived rats develop lesions on their paws and tails, suggesting possible deficits in the healing process. The purpose of this study was to assess the impact of rapid eye-movement (REM) sleep deprivation (RSD) on wound healing in a rat model. Male dark-hooded Long-Evans rats, 2,4 months old, were subjected to dorsal application of two sterile punch biopsies, each 3.5 mm in size. Biopsies were performed either immediately before or immediately after 5 days of sleep deprivation. Wound healing in REM sleep-deprived animals was compared with home cage control and yoked control animals. RSD did not produce differences in the rate of healing, regardless of the timing of the biopsy punch. RSD does not appear to have significant effects on wound healing and thus appears to act differently from other types of stressors on wound healing. [source]


A response to ,Patient safety', Levison A, Anaesthesia 2003; 58: 1236 and ,Sleep deprivation and performance', Price S R, Anaesthesia 2003; 58: 1238

ANAESTHESIA, Issue 5 2004
Francis Arnstein
No abstract is available for this article. [source]


Original Article: Maternal sleep deprivation, sedentary lifestyle and cooking smoke: Risk factors for miscarriage: A case control study

AUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 4 2010
Yasindu SAMARAWEERA
Aims:, To determine risk factors for miscarriage. Methods:, A case control study was carried out at the gynaecological wards and antenatal clinics of the De Soysa Maternity Hospital in Sri Lanka. A case was defined as that of mothers with a confirmed diagnosis of partial or full expulsion of the fetus during the first 28 weeks of gestation. Controls comprised ante-natal clinic attendees whose period of gestation was <28 weeks and carrying a viable fetus. Two hundred and thirty cases and 504 controls were selected. A pre-tested interviewer-administered questionnaire and modified life events inventory were used to gather data. Multivariate logistic regression was applied separately for first and second trimester miscarriages and the results were expressed as odds ratios (OR) and as 95% confidence intervals (95%CI). Results:, Sleeping ,8 h/day (OR:3.80, 95%CI:1.01,14.3) was found to be a risk factor for first trimester miscarriage controlling for the effect of period of gestation. Sleeping ,8 h/day (OR:2.04, 95%CI:1.24,3.37), standing ,3 h/day (OR:1.83, 95%CI:1.08,3.10), exposure to cooking smoke (OR:3.83, 95%CI:1.50,9.90) and physical trauma during the pregnancy (OR:43.2, 95%CI:4.55,411.4) were found to be risk factors for second trimester miscarriage controlling for the effect of period of gestation. Conclusions:, Sleep deprivation, a sedentary lifestyle, exposure to cooking smoke and physical trauma during pregnancy were risk factors for miscarriage. Most of the risk factors are therefore modifiable. [source]


Characterization of sleep,wake patterns in a novel transgenic mouse line overexpressing human prepro-orexin/hypocretin

ACTA PHYSIOLOGICA, Issue 3 2010
K. A. Mäkelä
Abstract Aim:, Orexin/hypocretin peptides are expressed in the lateral hypothalamus and involved in the regulation of autonomic functions, energy homeostasis and arousal states. The sleep disorder narcolepsy, which is characterized by excessive daytime sleepiness and occurrence of sudden rapid eye movement (REM) sleep, is associated with a loss of orexin neurones. Our study investigated the effects of orexins on sleep,wake patterns in a novel transgenic mouse line overexpressing the human prepro-orexin (hPPO) gene under the control of its endogenous promoter. Methods:, Orexin overexpression was investigated by PCR, Southern and Western blotting as well as immunohistochemistry. Polysomnographic recordings were performed for analyses of sleep,wake patterns and for electroencephalographic activity during 24 h baseline and during and after 6 h of sleep deprivation (SD). Results:, Transgenic hPPO mice had increased expression of human prepro-orexin (hPPO) and orexin-A in the hypothalamus. Transgene expression decreased endogenous orexin-2 receptors but not orexin-1 receptors in the hypothalamus without affecting orexin receptor levels in the basal forebrain, cortex or hippocampus. Transgenic mice compared with their wild type littermates showed small but significant differences in the amount of waking and slow wave sleep, particularly during the light,dark transition periods, in addition to a slight reduction in REM sleep during baseline and during recovery sleep after SD. Conclusion:, The hPPO-overexpressing mice show a small reduction in REM sleep, in addition to differences in vigilance state amounts in the light/dark transition periods, but overall the sleep,wake patterns of hPPO-overexpressing mice do not significantly differ from their wild type littermates. [source]


Subjective and objective sleep among depressed and non-depressed postnatal women

ACTA PSYCHIATRICA SCANDINAVICA, Issue 2 2009
S. K. Dørheim
Objective:, Women sleep less in the postnatal period and it has been suggested that mothers diagnosed with depression alternatively could be suffering from the effects of chronic sleep deprivation. Method:, From a population-based study, we recruited 42 women, of whom 21 scored ,10 on the Edinburgh Postnatal Depression Scale. Sleep was registered by the Pittsburgh Sleep Quality Index (PSQI), sleep diaries and actigraphy 2 months after delivery. Results:, There were significant differences in subjective sleep measured retrospectively by the PSQI between depressed and non-depressed women. In contrast, there were no significant differences in sleep measured prospectively by sleep diaries and actigraphy. Both depressed and non-depressed women had impaired sleep efficiency (82%) and were awake for about 1.5 h during the night. Primipara had worse sleep, measured by actigraphy, compared with multipara. Conclusion:, Measured objectively and prospectively, women with depression did not have worse sleep than non-depressed women. [source]


Interobserver reliability of visual interpretation of electroencephalograms in children with newly diagnosed seizures

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 5 2006
Hans Stroink MD
The reliability of visual interpretation of electroencephalograms (EEG) is of great importance in assessing the value of this diagnostic tool. We prospectively obtained 50 standard EEGs and 61 EEGs after partial sleep deprivation from 93 children (56 males, 37 females) with a mean age of 6 years 10 months (SE 5mo; range 4mo,15y 7mo) with one or more newly diagnosed, unprovoked seizures. Two clinical neurophysiologists independently classified the background pattern and the presence of epileptiform discharges or focal non-epileptiform abnormalities of each EEG. The agreement was substantial for the interpretation of the EEG as normal or abnormal (kappa 0.66), almost perfect for the presence of epileptiform discharges (kappa 0.83), substantial for the occurrence of an abnormal background pattern (kappa 0.73), and moderate for the presence of focal non-epileptiform discharges (kappa 0.54). In conclusion, the reliability of the visual interpretation of EEGs in children is almost perfect as regards the presence of epileptiform abnormalities, and moderate to substantial for the presence of other abnormalities. [source]


Homeostatic sleep regulation is preserved in mPer1 and mPer2 mutant mice

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2002
Caroline Kopp
Abstract A limited set of genes, Clock, Bmal1, mPer1, mPer2, mCry1 and mCry2, has been shown to be essential for the generation of circadian rhythms in mammals. It has been recently suggested that circadian genes might be involved in sleep regulation. We investigated the role of mPer1 and mPer2 genes in the homeostatic regulation of sleep by comparing sleep of mice lacking mPER1 (mPer1 mutants) or a functional mPER2 (mPer2 mutants), and wild-type controls (WT) after 6 h of sleep deprivation (SD). Our main result showed that after SD, all mice displayed the typical increase of slow-wave activity (SWA; EEG power density between 0.75 and 4 Hz) in nonREM sleep, reflecting the homeostatic response to SD. This increase was more prominent over the frontal cortex as compared to the occipital cortex. The genotypes did not differ in the effect of SD on the occipital EEG, while the effect on the frontal EEG was initially diminished in both mPer mutants. Differences between the genotypes were seen in the 24-h distribution of sleep, reflecting especially the phase advance of motor activity onset observed in mPer2 mutants. While the daily distribution of sleep was modulated by mPer1 and mPer2 genes, sleep homeostasis reflected by the SWA increase after 6-h SD was preserved in the mPer mutants. The results provide further evidence for the independence of the circadian and the homeostatic components underlying sleep regulation. [source]


Functional topography of the human nonREM sleep electroencephalogram

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2001
Luca A. Finelli
Abstract The sleep EEG of healthy young men was recorded during baseline and recovery sleep after 40 h of waking. To analyse the EEG topography, power spectra were computed from 27 derivations. Mean power maps of the nonREM sleep EEG were calculated for 1-Hz bins between 1.0 and 24.75 Hz. Cluster analysis revealed a topographic segregation into distinct frequency bands which were similar for baseline and recovery sleep, and corresponded closely to the traditional frequency bands. Hallmarks of the power maps were the frontal predominance in the delta and alpha band, the occipital predominance in the theta band, and the sharply delineated vertex maximum in the sigma band. The effect of sleep deprivation on EEG topography was determined by calculating the recovery/baseline ratio of the power spectra. Prolonged waking induced an increase in power in the low-frequency range (1,10.75 Hz) which was largest over the frontal region, and a decrease in power in the sigma band (13,15.75 Hz) which was most pronounced over the vertex. The topographic pattern of the recovery/baseline power ratio was similar to the power ratio between the first and second half of the baseline night. These results indicate that changes in sleep propensity are reflected by specific regional differences in EEG power. The predominant increase of low-frequency power in frontal areas may be due to a high ,recovery need' of the frontal heteromodal association areas of the cortex. [source]


Sleep and the metabolic syndrome

EXPERIMENTAL PHYSIOLOGY, Issue 1 2007
Robert Wolk
The metabolic syndrome represents a clustering of several interrelated risk factors of metabolic origin that are thought to increase cardiovascular risk. It is still uncertain whether this clustering results from multiple underlying risk factors or whether it has a single cause. One metabolic abnormality that may underlie several clinical characteristics of the metabolic syndrome is insulin resistance. This review discusses the evidence that sleep disturbances (obstructive sleep apnoea, sleep deprivation and shift work) may independently lead to the development of both insulin resistance and individual clinical components of the metabolic syndrome. The converse may also be true, in that metabolic abnormalities associated with the metabolic syndrome and insulin resistance may potentially exacerbate sleep disorders. The notion that sleep disturbances exert detrimental metabolic effects may help explain the increasing prevalence of the metabolic syndrome and insulin resistance in the general population and may have important implications for population-based approaches to combat the increasing epidemic of metabolic and cardiovascular disease. [source]


Circadian rhythm disturbances in depression,

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2008
Anne Germain
Abstract Objective The aim of this article is to review progress in understanding the mechanisms that underlie circadian and sleep rhythms, and their role in the pathogenesis and treatment of depression. Methods Literature was selected principally by Medline searches, and additional reports were identified based on ongoing research activities in the authors' laboratory. Results Many physiological processes show circadian rhythms of activity. Sleep and waking are the most obvious circadian rhythms in mammals. There is considerable evidence that circadian and sleep disturbances are important in the pathophysiology of mood disorders. Depressed patients often show altered circadian rhythms, sleep disturbances, and diurnal mood variation. Chronotherapies, including bright light exposure, sleep deprivation, and social rhythm therapies, may be useful adjuncts in non-seasonal and seasonal depression. Antidepressant drugs have marked effects on circadian processes and sleep. Conclusions Recent progress in understanding chronobiological and sleep regulation mechanisms may provide novel insights and avenues into the development of new pharmacological and behavioral treatment strategies for mood disorders. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Development and implementation of a noise reduction intervention programme: a pre- and postaudit of three hospital wards

JOURNAL OF CLINICAL NURSING, Issue 23 2009
Annette Richardson
Aims., By developing, implementing and delivering a noise reduction intervention programme, we aimed to attempt to reduce the high noise levels on inpatient wards. Background., Sleep is essential for human survival and sleep deprivation is detrimental to health and well being. Exposure to noise has been found to disrupt sleep in hospitalised patients which is to be expected as noise levels have been measured and reported as high. Design., A primarily nursing focused, multi-method approach, involving development of clinical guidelines, ward environment review and a staff noise awareness and education programme, was used to target mainly nursing staff plus other healthcare staff on three wards within one hospital. Methods., This practice development initiative was carried out in three key phases (1) Preaudit of ward noise levels, (2) The development, implementation and delivery of a noise reduction intervention programme, (3) Postaudit of ward noise levels. Results., Preintervention average peak decibel levels over 24 hours were found to be 96·48 dB(A) and postintervention average peak decibel levels were measured at 77·52 dB(A), representing an overall significant reduction in noise levels (p < 0·001). Conclusions., This study describes one way to reduce peak noise levels on inpatient hospital wards. Relevance to clinical practice., Sleep deprivation is detrimental to patients with acute illness, so any developments to improve patients' sleep are important. Nurses have a key role in leading, developing and implementing changes to reduce peak noise levels on inpatient wards in hospitals. This nurse-led practice development programme has demonstrated how improvements can be achieved by significantly reducing peak noise levels using simple multi-method change strategies. [source]


Systematic review on the effectiveness of caffeine abstinence on the quality of sleep

JOURNAL OF CLINICAL NURSING, Issue 1 2009
Celia WM Sin
Aim., The aim of the present study is to review the effects of caffeine abstinence on the quality of sleep. Background., Insomnia is a common problem and abstinence from caffeine is the most popular component in sleep hygiene advice. However, there have been inconsistent results relating to the effectiveness of caffeine abstinence in improving sleep. Design., Systematic review. Methods., We browsed several electronic databases and reference lists of articles about the correlation of caffeine consumption and sleep deprivation. We selected the articles according to predefined inclusion and exclusion criteria. Two reviewers assessed the quality of trials, which were selected according to the Jadad quality assessment scale. We included the trials scoring three or above in the systematic review and extracted their data. We assessed the heterogeneity of the studies before we considered whether or not to combine the studies' results. Results., Three randomised control trials fulfilled the selection criteria among which two trials scored ,3 on the Jadad scale. We included these two trials in our systematic review. The designs and outcome measurements of these two trials were not homogeneous, therefore, we did not combine their results. Instead, we conducted a critical appraisal. In one trial, caffeine abstinence was associated with significant lengthening of sleep duration (p < 0·01) and better sleep quality (p < 0·05). In another trial, subjects had less difficulty falling asleep on days when they drank decaffeinated coffee (p < 0·05). Conclusions., The results showed that caffeine abstinence for a whole day could improve sleep quality. Thus, health practitioners were recommended to include caffeine abstinence in the instructions for sleep hygiene. Relevance to clinical practice., This study demonstrates the effectiveness of caffeine abstinence in improving sleep quality. It provides evidence for the practice of including caffeine abstinence in sleep hygiene advice. [source]


Sleep and Rest Regulation in Young and Old Oestrogen-Deficient Female Mice

JOURNAL OF NEUROENDOCRINOLOGY, Issue 8 2006
V. V. Vyazovskiy
The effect of circulating oestrogen deficiency on sleep regulation and locomotor activity was investigated in aromatase cytochrome P450 deficient mice (ArKO) and wild-type (WT) controls. Sleep was recorded in 3-month old mice during a 24-h baseline day, 6-h sleep deprivation (SD) and 18-h recovery, and activity was recorded at the age of 3, 9 and 12 months. In mice deficient of oestrogen, the total amount of sleep per 24 h was the same as in WT controls. However, in ArKO mice, sleep was enhanced in the dark period at the expense of sleep in the light phase, and was more fragmented than sleep in WT mice. This redistribution of sleep resulted in a damped amplitude of slow-wave activity (SWA; power between 0.75,4.0 Hz) in non-rapid eye movement sleep across 24 h. After SD, the rebound of sleep and SWA was similar between the genotypes, suggesting that oestrogen deficiency does not affect the mechanisms maintaining the homeostatic balance between the amount of sleep and its intensity. Motor activity decreased with age in both genotypes and was lower in ArKO mice compared to WT at all three ages. After SD, the amount of rest in 3-month old WT mice increased above baseline and was more consolidated. Both effects were less pronounced in ArKO mice, reflecting the baseline differences between the genotypes. The results indicate that despite the pronounced redistribution of sleep and motor activity in oestrogen deficient mice, the basic homeostatic mechanisms of sleep regulation in ArKO mice remain intact. [source]


Paradoxical Sleep Deprivation and Sleep Recovery: Effects on the Hypothalamic,Pituitary,Adrenal Axis Activity, Energy Balance and Body Composition of Rats

JOURNAL OF NEUROENDOCRINOLOGY, Issue 4 2006
D. C. Hipólide
Abstract Numerous studies indicate that sleep deprivation alters energy expenditure. However, this conclusion is drawn from indirect measurements. In the present study, we investigated alterations of energy expenditure, body composition, blood glucose levels, plasma insulin, adrenocorticotropic hormone (ACTH) and corticosterone levels immediately after 4 days of sleep deprivation or after 4 days of sleep recovery. Rats were sleep deprived or maintained in a control environment (groups sleep-deprived/deprivation and control/deprivation). One half of these animals were sacrificed at the end of the deprivation period and the other half was transported to metabolic cages, where they were allowed to sleep freely (groups sleep-deprived/recovery and control/recovery). At the end of the sleep recovery period, these rats were sacrificed. After sleep deprivation, sleep-deprived rats exhibited loss of body weight, augmented energy expenditure and reduced metabolic efficiency compared to control rats. These alterations were normalised during the sleep recovery period. The body composition of sleep-deprived rats was altered insofar as there was a loss of fat content and gain of protein content in the carcass compared to control rats. However, these alterations were not reversed by sleep recovery. Finally, plasma levels of insulin were reduced during the sleep deprivation period in both control and sleep deprived groups compared to the recovery period. After the deprivation period, plasma ACTH and corticosterone levels were increased in sleep-deprived rats compared to control rats, and although ACTH levels were similar between the groups after the sleep recovery period, corticosterone levels remained elevated in sleep-deprived rats after this period. By means of direct measurements of metabolism, our results showed that sleep deprivation produces increased energy expenditure and loss of fat content. Most of the alterations were reversed by sleep recovery, except for corticosterone levels and body composition. [source]


Increased turnover of Na-K ATPase molecules in rat brain after rapid eye movement sleep deprivation

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2003
Sudipta Majumdar
Abstract It has been shown that rapid eye movement (REM) sleep deprivation increases Na-K ATPase activity. Based on kinetic study, it was proposed that increased activity was due to enhanced turnover of enzyme molecules. To test this, anti-,1 Na-K ATPase monoclonal antibody (mAb 9A7) was used to label Na-K ATPase molecules. These labeled enzymes were quantified on neuronal membrane by two methods: histochemically on neurons in tissue sections from different brain areas, and by Western blot analysis in control and REM sleep-deprived rat brains. The specific enzyme activity was also estimated and found to be increased, as in previous studies. The results confirmed our hypothesis that after REM sleep deprivation, increased Na-K ATPase activity was at least partly due to increased turnover of Na-K ATPase molecules in the rat brain. © 2003 Wiley-Liss, Inc. [source]


A Selective Review of Maternal Sleep Characteristics in the Postpartum Period

JOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 1 2009
Lauren P. Hunter
ABSTRACT Objective: To determine the current knowledge of postpartum womens' sleep patterns, sleep disturbances, consequences of sleep disturbances, and known strategies for prevention in order to provide best practice recommendations for health care providers. Data Sources: A literature search from 1969 through February 2008 was conducted using the CINHL, Index of Allied Health Literature, Ovid, PsycINFO, and PubMed electronic databases in addition to reference lists from selected articles and other key references. Search terms included sleep, postpartum, sleep deprivation, and sleep disturbance. Study Selection: A critical review of all relevant articles from the data sources was conducted with attention to the needs of postpartum womens' sleep and implications for health care providers. Data Extraction: Literature was reviewed and organized into groups with similar characteristics. Data Synthesis: An integrative review of the literature summarized the current state of research related to sleep alterations in postpartum women. Conclusions: Postpartum women experience altered sleep patterns that may lead to sleep disturbances. The most common reasons for sleep disturbances are related to newborn sleep and feeding patterns. Although present, the relationships among sleep disturbance, fatigue, and depression in postpartum women lack clarity due to their ambiguous definitions and the variety of the studies conducted. Providers should encourage prenatal education that assists the couple in developing strategies for decreasing postpartum sleep deprivation. Alterations of in-hospital care and home care should be incorporated to improve the new family's sleep patterns. [source]


Adolescents' Sleep Behaviors and Perceptions of Sleep

JOURNAL OF SCHOOL HEALTH, Issue 5 2009
Heather Noland MEd
ABSTRACT Background:, Sleep duration affects the health of children and adolescents. Shorter sleep durations have been associated with poorer academic performance, unintentional injuries, and obesity in adolescents. This study extends our understanding of how adolescents perceive and deal with their sleep issues. Methods:, General education classes were randomly selected from a convenience sample of three high schools in the Midwest. Three hundred eighty-four ninth- to twelfth-grade students (57%) completed a self-administered valid and reliable questionnaire on sleep behaviors and perceptions of sleep. Results:, Most respondents (91.9%) obtained inadequate sleep (, 9 hours) on most school nights of the week, with 10% reporting less than 6 hours of sleep each week night. The majority indicated that not getting enough sleep had the following effects on them: being more tired during the day (93.7%), having difficulty paying attention (83.6%), lower grades (60.8%), increase in stress (59.0%), and having difficulty getting along with others (57.7%). Some students reported engaging in harmful behaviors to help them sleep: taking sleeping pills (6.0%), smoking a cigarette to relax (5.7%), and drinking alcohol in the evening (2.9%). Students who received fewer hours of sleep were significantly more likely to report being stressed (p = .02) and were more likely to be overweight (p = .04). Conclusions:, Inadequate sleep time may be contributing to adolescent health problems such as increased stress and obesity. Findings indicate a need for sleep hygiene education for adolescents and their parents. A long-term solution to chronic sleep deprivation among high school students could include delaying high school start times, such as was done successfully in the Minneapolis Public School District. [source]


Elementary Students' Sleep Habits and Teacher Observations of Sleep-Related Problems

JOURNAL OF SCHOOL HEALTH, Issue 2 2005
Denise H. Amschler PhD Professor
ABSTRACT: Sleep affects the health and well-being of children and plays a key role in preventing disease and injury, stability of mood, and ability to learn. Unfortunately, children often do not get adequate sleep on a regular basis. This study surveyed 199 fifth-grade students regarding their sleep habits using the Sleep Self-Report (SSR) instrument (child's form), the Morningness/Eveningness (M/E) Scale, and additional demographic questions. Students' teachers also were asked to evaluate their students' behavior using the Teacher's Daytime Sleepiness Questionnaire (TDSQ). Results indicated many students experienced problems with sleep-related behavior. However, correlating the TDSQ scale with the SSR Daytime Sleepiness Subscale produced a weak correlation coefficient, indicating teachers may not be able to accurately identify students with sleep problems. Overall findings indicated these students displayed sleep behavior similar to other US children. However, research involving children's sleep behavior is limited, and more research is needed. Parents should monitor their children's sleep times, and teachers need to be aware how sleep deprivation can affect children's mood, reaction time, and concentration. Health education curricula need to include sleep-related instruction at all grade levels to address this concern. [source]


The effects of one night of sleep deprivation on known-risk and ambiguous-risk decisions

JOURNAL OF SLEEP RESEARCH, Issue 3 2007
BENJAMIN S. MCKENNA
Summary Sleep deprivation has been shown to alter decision-making abilities. The majority of research has utilized fairly complex tasks with the goal of emulating 'real-life' scenarios. Here, we use a Lottery Choice Task (LCT) which assesses risk and ambiguity preference for both decisions involving potential gains and those involving potential losses. We hypothesized that one night of sleep deprivation would make subjects more risk seeking in both gains and losses. Both a control group and an experimental group took the LCT on two consecutive days, with an intervening night of either sleep or sleep deprivation. The control group demonstrated that there was no effect of repeated administration of the LCT. For the experimental group, results showed significant interactions of night (normal sleep versus total sleep deprivation, TSD) by frame (gains versus losses), which demonstrate that following as little as 23 h of TSD, the prototypical response to decisions involving risk is altered. Following TSD, subjects were willing to take more risk than they ordinarily would when they were considering a gain, but less risk than they ordinarily would when they were considering a loss. For ambiguity preferences, there seems to be no direct effect of TSD. These findings suggest that, overall, risk preference is moderated by TSD, but whether an individual is willing to take more or less risk than when well-rested depends on whether the decision is framed in terms of gains or losses. [source]


Impaired decision making following 49 h of sleep deprivation

JOURNAL OF SLEEP RESEARCH, Issue 1 2006
WILLIAM D. S. KILLGORE
Summary Sleep deprivation reduces regional cerebral metabolism within the prefrontal cortex, the brain region most responsible for higher-order cognitive processes, including judgment and decision making. Accordingly, we hypothesized that two nights of sleep loss would impair decision making quality and lead to increased risk-taking behavior on the Iowa Gambling Task (IGT), which mimics real-world decision making under conditions of uncertainty. Thirty-four healthy participants completed the IGT at rested baseline and again following 49.5 h of sleep deprivation. At baseline, volunteers performed in a manner similar to that seen in most samples of healthy normal individuals, rapidly learning to avoid high-risk decks and selecting more frequently from advantageous low-risk decks as the game progressed. After sleep loss, however, volunteers showed a strikingly different pattern of performance. Relative to rested baseline, sleep-deprived individuals tended to choose more frequently from risky decks as the game progressed, a pattern similar to, though less severe than, previously published reports of patients with lesions to the ventromedial prefrontal cortex. Although risky decision making was not related to participant age when tested at rested baseline, age was negatively correlated with advantageous decision making on the IGT, when tested following sleep deprivation (i.e. older subjects made more risky choices). These findings suggest that cognitive functions known to be mediated by the ventromedial prefrontal cortex, including decision making under conditions of uncertainty, may be particularly vulnerable to sleep loss and that this vulnerability may become more pronounced with increased age. [source]


Effects of sleep deprivation on wound healing

JOURNAL OF SLEEP RESEARCH, Issue 3 2005
L. MOSTAGHIMI
Summary Sleep deprivation is widely regarded as a stressor and has been shown to have significant effects on host defences. Severely sleep-deprived rats develop lesions on their paws and tails, suggesting possible deficits in the healing process. The purpose of this study was to assess the impact of rapid eye-movement (REM) sleep deprivation (RSD) on wound healing in a rat model. Male dark-hooded Long-Evans rats, 2,4 months old, were subjected to dorsal application of two sterile punch biopsies, each 3.5 mm in size. Biopsies were performed either immediately before or immediately after 5 days of sleep deprivation. Wound healing in REM sleep-deprived animals was compared with home cage control and yoked control animals. RSD did not produce differences in the rate of healing, regardless of the timing of the biopsy punch. RSD does not appear to have significant effects on wound healing and thus appears to act differently from other types of stressors on wound healing. [source]


Investigating the interaction between the homeostatic and circadian processes of sleep,wake regulation for the prediction of waking neurobehavioural performance

JOURNAL OF SLEEP RESEARCH, Issue 3 2003
Hans P. A. Van Dongen
Summary The two-process model of sleep regulation has been applied successfully to describe, predict, and understand sleep,wake regulation in a variety of experimental protocols such as sleep deprivation and forced desynchrony. A non-linear interaction between the homeostatic and circadian processes was reported when the model was applied to describe alertness and performance data obtained during forced desynchrony. This non-linear interaction could also be due to intrinsic non-linearity in the metrics used to measure alertness and performance, however. Distinguishing these possibilities would be of theoretical interest, but could also have important implications for the design and interpretation of experiments placing sleep at different circadian phases or varying the duration of sleep and/or wakefulness. Although to date no resolution to this controversy has been found, here we show that the issue can be addressed with existing data sets. The interaction between the homeostatic and circadian processes of sleep,wake regulation was investigated using neurobehavioural performance data from a laboratory experiment involving total sleep deprivation. The results provided evidence of an actual non-linear interaction between the homeostatic and circadian processes of sleep,wake regulation for the prediction of waking neurobehavioural performance. [source]


Electrodermal activity during total sleep deprivation and its relationship with other activation and performance measures

JOURNAL OF SLEEP RESEARCH, Issue 2 2002
E. Miró
The present study analyses the variations of the skin resistance level (SRL) during 48 h of total sleep deprivation (TSD) and its relationship to body temperature, self-informed sleepiness in the Stanford Sleepiness Scale (SSS), and reaction time (RT). All of the variables were evaluated every 2 h except for the SSS, which was evaluated every hour. A total of 30 healthy subjects (15 men and 15 women) from 18 to 24 years old participated in the experiment. Analyses of variance (ANOVAs) with TSD days and time-of-day as factors showed a substantial increase of SRL, SSS, and RT, and a decrease in body temperature marked by strong circadian oscillations. The interaction between day by time-of-day was only significant for RT. Furthermore, Pearson's correlations showed that the increase of SRL is associated to the decrease in temperature (mean r=,0.511), the increase of SSS (mean r=0.509), and the deterioration of RT (mean r=0.425). The results support previous TSD reports and demonstrate the sensitivity of SRL to TSD. The non-invasive character of SRL, its simplicity, and its relationships with other activation parameters, widely validated by previous literature, convert SRL into an interesting and useful measure in this field. [source]


Long-term vs. short-term processes regulating REM sleep

JOURNAL OF SLEEP RESEARCH, Issue 1 2002
PAUL FRANKEN
In cats, rats, and mice, the amount of rapid eye movement sleep (REMS) lost during a sleep deprivation (SD) predicts the subsequent REMS rebound during recovery sleep. This suggests that REMS is homeostatically regulated and that a need or pressure for REMS accumulates in its absence, i.e. during both wakefulness and non-rapid eye movement sleep (NREMS). Conversely, it has been proposed that REMS pressure accumulates exclusively during NREMS [Benington and Heller, Am. J. Physiol. 266 (1994) R1992; Prog. Neurobiol. 44 (1994b) 433]. This hypothesis is based on the analysis of the duration of successive NREMS and REMS episodes and of electroencephalogram (EEG) events preceding REMS. Pre-REMS events (PREs) do not always result in sustained REMS and can thus be regarded as REMS attempts that increase as NREMS progresses. It is assumed that two processes regulating REMS can resolve the apparent contradiction between these two concepts: a `long-term' process that homeostatically regulates the daily REMS amount and a `short-term' process that regulates the NREM,REMS cycle. These issues were addressed in two SD experiments in rats. The two SDs varied in length (12 and 24 h) and resulted in very similar compensatory changes in NREMS but evoked very different changes for all REMS parameters studied. The large REMS increase observed after 24-h SD was accompanied by a reduction in unsuccessful PREs and an increase in sustained REMS episodes, together resulting in a threefold increase in the success-rate to enter REMS. Changes in success-rate matched those of a theoretically derived long-term REMS pressure. The SD induced changes in sleep architecture could be reproduced by assuming that the increased long-term REMS pressure interacts with the short-term process by increasing the probability to enter and remain in REMS. [source]


Mind, Brain, Education, and Biological Timing

MIND, BRAIN, AND EDUCATION, Issue 1 2008
Diego A. Golombek
ABSTRACT, Circadian rhythms, in particular the sleep,wake cycle, modulate most, if not all, aspects of physiology and behavior. Their impact on education has recently begun to be understood, including a clear positive relationship between sleep and learning. In fact, sleep deprivation, common to adolescents throughout the world, has a deep effect on academic performance, and this fact is often increased by inadequate school schedules. This special issue of Mind, Brain, and Education deals with the relation between biological rhythms and learning, as discussed in an International Mind, Brain, and Education Society meeting that took place in Erice, Italy in May 2007. The articles (with contributors from Brazil, Croatia, Sweden, Spain, United Kingdom, United States, and Argentina) cover several aspects of this fundamental link between timing and education and suggest strategies to optimize school and sleep schedules for a better quality of life and improved academic performance of students. [source]


Is losing sleep making us obese?

NUTRITION BULLETIN, Issue 4 2008
K. E. Jones
Summary Obesity has become pandemic. In America, as obesity has increased, the amount of sleep Americans get per night has decreased, and studies are now showing an association. Epidemiological studies on short sleep duration (SSD) and obesity have been conducted in children and adults, and show an overall positive association. Leptin and ghrelin, two hormones that control appetite, have been studied as a mechanism for SSD causing obesity. Low leptin and high ghrelin levels have been seen in sleep deprivation, the effect of which is an increase in appetite that could be linked to obesity. Decreasing media use, namely television and computers, could be one way to increase nightly sleep and potentially help people lose weight. Paediatric studies have shown an association with bedroom media use and shorter sleep duration. Adult studies are lacking in this area. Limitations in the literature include self-report in a majority of sleep studies and only a suggested causal link between SSD and obesity among all of the epidemiological studies. In conclusion, obesity is a global problem with great complexity. Encouraging people to get more sleep could be one part of the solution to help them lose weight and gain health. [source]