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Sample records for spontaneous sleep slow

  1. Spontaneous K-Complex Density in Slow-Wave Sleep

    PubMed Central

    Zannat, Wassilatul; Pandi-Perumal, Seithikurippu R.; BaHammam, Ahmed S.; Hussain, M. Ejaz

    2016-01-01

    Purpose To study spontaneous K-complex (KC) densities during slow-wave sleep. The secondary objective was to estimate intra-non-rapid eye movement (NREM) sleep differences in KC density. Materials and Methods It is a retrospective study using EEG data included in polysomnographic records from the archive at the sleep research laboratory of the Centre for Physiotherapy and Rehabilitation Sciences, Jamia Millia Islamia, India. The EEG records of 4459 minutes were used. The study presents a manual identification investigation of KCs in 17 healthy young adult male volunteers (age = 23.82±3.40 years and BMI = 23.42±4.18 kg/m2). Results N3 had a higher KC density than N2 (Z = -2.485, p = 0.013) for all of the probes taken together. Four EEG probes had a higher probe-specific KC density during N3. The inter-probe KC density differed significantly during N2 (χ2 = 67.91, p < .001), N3 (χ2 = 70.62, p < .001) and NREM (χ2 = 68.50, p < .001). The percent distribution of KC decreased uniformly with sleep cycles. Conclusion The inter-probe differences during N3 establish the fronto-central dominance of the KC density regardless of sleep stage. This finding supports one local theory of KC generation. The significantly higher KC density during N3 may imply that the neuro-anatomical origin of slow-wave activity and KC is the same. This temporal alignment with slow-wave activity supports the sleep-promoting function of the KC. PMID:26963714

  2. Slow spontaneous hemodynamic oscillations during sleep measured with near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Virtanen, Jaakko; Näsi, Tiina; Noponen, Tommi; Toppila, Jussi; Salmi, Tapani; Ilmoniemi, Risto J.

    2011-07-01

    Spontaneous cerebral hemodynamic oscillations below 100 mHz reflect the level of cerebral activity, modulate hemodynamic responses to tasks and stimuli, and may aid in detecting various pathologies of the brain. Near-infrared spectroscopy (NIRS) is ideally suited for both measuring spontaneous hemodynamic oscillations and monitoring sleep, but little research has been performed to combine these two applications. We analyzed 30 all-night NIRS-electroencephalography (EEG) sleep recordings to investigate spontaneous hemodynamic activity relative to sleep stages determined by polysomnography. Signal power of hemodynamic oscillations in the low-frequency (LF, 40-150 mHz) and very-low-frequency (VLF, 3-40 mHz) bands decreased in slow-wave sleep (SWS) compared to light sleep (LS) and rapid-eye-movement (REM) sleep. No statistically significant (p < 0.05) differences in oscillation power between LS and REM were observed. However, the period of VLF oscillations around 8 mHz increased in REM sleep in line with earlier studies with other modalities. These results increase our knowledge of the physiology of sleep, complement EEG data, and demonstrate the applicability of NIRS to studying spontaneous hemodynamic fluctuations during sleep.

  3. Phase of Spontaneous Slow Oscillations during Sleep Influences Memory-Related Processing of Auditory Cues

    PubMed Central

    Creery, Jessica D.; Paller, Ken A.

    2016-01-01

    Slow oscillations during slow-wave sleep (SWS) may facilitate memory consolidation by regulating interactions between hippocampal and cortical networks. Slow oscillations appear as high-amplitude, synchronized EEG activity, corresponding to upstates of neuronal depolarization and downstates of hyperpolarization. Memory reactivations occur spontaneously during SWS, and can also be induced by presenting learning-related cues associated with a prior learning episode during sleep. This technique, targeted memory reactivation (TMR), selectively enhances memory consolidation. Given that memory reactivation is thought to occur preferentially during the slow-oscillation upstate, we hypothesized that TMR stimulation effects would depend on the phase of the slow oscillation. Participants learned arbitrary spatial locations for objects that were each paired with a characteristic sound (eg, cat–meow). Then, during SWS periods of an afternoon nap, one-half of the sounds were presented at low intensity. When object location memory was subsequently tested, recall accuracy was significantly better for those objects cued during sleep. We report here for the first time that this memory benefit was predicted by slow-wave phase at the time of stimulation. For cued objects, location memories were categorized according to amount of forgetting from pre- to post-nap. Conditions of high versus low forgetting corresponded to stimulation timing at different slow-oscillation phases, suggesting that learning-related stimuli were more likely to be processed and trigger memory reactivation when they occurred at the optimal phase of a slow oscillation. These findings provide insight into mechanisms of memory reactivation during sleep, supporting the idea that reactivation is most likely during cortical upstates. SIGNIFICANCE STATEMENT Slow-wave sleep (SWS) is characterized by synchronized neural activity alternating between active upstates and quiet downstates. The slow-oscillation upstates are

  4. Source modeling sleep slow waves

    PubMed Central

    Murphy, Michael; Riedner, Brady A.; Huber, Reto; Massimini, Marcello; Ferrarelli, Fabio; Tononi, Giulio

    2009-01-01

    Slow waves are the most prominent electroencephalographic (EEG) feature of sleep. These waves arise from the synchronization of slow oscillations in the membrane potentials of millions of neurons. Scalp-level studies have indicated that slow waves are not instantaneous events, but rather they travel across the brain. Previous studies of EEG slow waves were limited by the poor spatial resolution of EEGs and by the difficulty of relating scalp potentials to the activity of the underlying cortex. Here we use high-density EEG (hd-EEG) source modeling to show that individual spontaneous slow waves have distinct cortical origins, propagate uniquely across the cortex, and involve unique subsets of cortical structures. However, when the waves are examined en masse, we find that there are diffuse hot spots of slow wave origins centered on the lateral sulci. Furthermore, slow wave propagation along the anterior−posterior axis of the brain is largely mediated by a cingulate highway. As a group, slow waves are associated with large currents in the medial frontal gyrus, the middle frontal gyrus, the inferior frontal gyrus, the anterior cingulate, the precuneus, and the posterior cingulate. These areas overlap with the major connectional backbone of the cortex and with many parts of the default network. PMID:19164756

  5. Spontaneous sleep and homeostatic sleep regulation in ghrelin knockout mice.

    PubMed

    Szentirmai, Eva; Kapás, Levente; Sun, Yuxiang; Smith, Roy G; Krueger, James M

    2007-07-01

    Ghrelin is well known for its feeding and growth hormone-releasing actions. It may also be involved in sleep regulation; intracerebroventricular administration and hypothalamic microinjections of ghrelin stimulate wakefulness in rats. Hypothalamic ghrelin, together with neuropeptide Y and orexin form a food intake-regulatory circuit. We hypothesized that this circuit also promotes arousal. To further investigate the role of ghrelin in the regulation of sleep-wakefulness, we characterized spontaneous and homeostatic sleep regulation in ghrelin knockout (KO) and wild-type (WT) mice. Both groups of mice exhibited similar diurnal rhythms with more sleep and less wakefulness during the light period. In ghrelin KO mice, spontaneous wakefulness and rapid-eye-movement sleep (REMS) were slightly elevated, and non-rapid-eye-movement sleep (NREMS) was reduced. KO mice had more fragmented NREMS than WT mice, as indicated by the shorter and greater number of NREMS episodes. Six hours of sleep deprivation induced rebound increases in NREMS and REMS and biphasic changes in electroencephalographic slow-wave activity (EEG SWA) in both genotypes. Ghrelin KO mice recovered from NREMS and REMS loss faster, and the delayed reduction in EEG SWA, occurring after sleep loss-enhanced increases in EEG SWA, was shorter-lasting compared with WT mice. These findings suggest that the basic sleep-wake regulatory mechanisms in ghrelin KO mice are not impaired and they are able to mount adequate rebound sleep in response to a homeostatic challenge. It is possible that redundancy in the arousal systems of the brain or activation of compensatory mechanisms during development allow for normal sleep-wake regulation in ghrelin KO mice. PMID:17409264

  6. Human Gamma Oscillations during Slow Wave Sleep

    PubMed Central

    Valderrama, Mario; Crépon, Benoît; Botella-Soler, Vicente; Martinerie, Jacques; Hasboun, Dominique; Alvarado-Rojas, Catalina; Baulac, Michel; Adam, Claude; Navarro, Vincent; Le Van Quyen, Michel

    2012-01-01

    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. PMID:22496749

  7. Slow Wave Sleep and Long Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Whitmire, Alexandra; Orr, Martin; Arias, Diana; Rueger, Melanie; Johnston, Smith; Leveton, Lauren

    2012-01-01

    While ground research has clearly shown that preserving adequate quantities of sleep is essential for optimal health and performance, changes in the progression, order and /or duration of specific stages of sleep is also associated with deleterious outcomes. As seen in Figure 1, in healthy individuals, REM and Non-REM sleep alternate cyclically, with stages of Non-REM sleep structured chronologically. In the early parts of the night, for instance, Non-REM stages 3 and 4 (Slow Wave Sleep, or SWS) last longer while REM sleep spans shorter; as night progresses, the length of SWS is reduced as REM sleep lengthens. This process allows for SWS to establish precedence , with increases in SWS seen when recovering from sleep deprivation. SWS is indeed regarded as the most restorative portion of sleep. During SWS, physiological activities such as hormone secretion, muscle recovery, and immune responses are underway, while neurological processes required for long term learning and memory consolidation, also occur. The structure and duration of specific sleep stages may vary independent of total sleep duration, and changes in the structure and duration have been shown to be associated with deleterious outcomes. Individuals with narcolepsy enter sleep through REM as opposed to stage 1 of NREM. Disrupting slow wave sleep for several consecutive nights without reducing total sleep duration or sleep efficiency is associated with decreased pain threshold, increased discomfort, fatigue, and the inflammatory flare response in skin. Depression has been shown to be associated with a reduction of slow wave sleep and increased REM sleep. Given research that shows deleterious outcomes are associated with changes in sleep structure, it is essential to characterize and mitigate not only total sleep duration, but also changes in sleep stages.

  8. The nature of spontaneous sleep across adulthood.

    PubMed

    Campbell, Scott S; Murphy, Patricia J

    2007-03-01

    The decline in sleep quality that often accompanies aging is thought to be the consequence of alterations in both circadian and homeostatic processes widely assumed to be responsible for sleep/wake regulation. A number of experimental approaches have been used to examine various aspects of age-related sleep changes, but none has examined spontaneous sleep across the entire 24-h day. Using the 'disentrainment' protocol, we studied such sleep in young, middle-aged and older adults. All subjects exhibited polyphasic sleep patterns, characterized by relatively short intervals of both sleep and waking. Whereas, the average duration of major nighttime sleep was significantly shorter in middle-aged and older subjects than in young adults, daytime napping was essentially unaffected by age. Comparisons of sleep and circadian variables between age groups suggest differential effects on sleep of the two regulatory processes, with changes in homeostatic drive preceding those of the circadian component. These findings add to a surprisingly scant literature on the longitudinal decline in sleep quality associated with aging. PMID:17309760

  9. Slow Wave Sleep and Long Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Orr, M.; Whitmire, A.; Arias, D.; Leveton, L.

    2011-01-01

    To review the literature on slow wave sleep (SWS) in long duration space flight, and place this within the context of the broader literature on SWS particularly with respect to analogous environments such as the Antarctic. Explore how SWS could be measured within the International Space Station (ISS) context with the aim to utilize the ISS as an analog for future extra-orbital long duration missions. Discuss the potential use of emergent minimally intrusive wireless technologies like ZEO for integrated prelaunch, flight, and return to Earth analysis and optimization of SWS (and general quality of sleep).

  10. Sleep slow-wave activity regulates cerebral glycolytic metabolism.

    PubMed

    Wisor, Jonathan P; Rempe, Michael J; Schmidt, Michelle A; Moore, Michele E; Clegern, William C

    2013-08-01

    Non-rapid eye movement sleep (NREMS) onset is characterized by a reduction in cerebral metabolism and an increase in slow waves, 1-4-Hz oscillations between relatively depolarized and hyperpolarized states in the cerebral cortex. The metabolic consequences of slow-wave activity (SWA) at the cellular level remain uncertain. We sought to determine whether SWA modulates the rate of glycolysis within the cerebral cortex. The real-time measurement of lactate concentration in the mouse cerebral cortex demonstrates that it increases during enforced wakefulness. In spontaneous sleep/wake cycles, lactate concentration builds during wakefulness and rapid eye movement sleep and declines during NREMS. The rate at which lactate concentration declines during NREMS is proportional to the magnitude of electroencephalographic (EEG) activity at frequencies of <10 Hz. The induction of 1-Hz oscillations, but not 10-Hz oscillations, in the electroencephalogram by optogenetic stimulation of cortical pyramidal cells during wakefulness triggers a decline in lactate concentration. We conclude that cerebral SWA promotes a decline in the rate of glycolysis in the cerebral cortex. These results demonstrate a cellular energetic function for sleep SWA, which may contribute to its restorative effects on brain function. PMID:22767634

  11. Two features of sleep slow waves: homeostatic and reactive aspects--from long term to instant sleep homeostasis.

    PubMed

    Halász, Péter; Bódizs, Róbert; Parrino, Liborio; Terzano, Mario

    2014-10-01

    In this paper we reviewed results of sleep research that have changed the views about sleep slow wave homeostasis, which involve use-dependent and experience-dependent local aspects to understand more of the physiology of plastic changes during sleep. Apart from the traditional homeostatic slow-wave economy, we also overviewed research on the existence and role of reactive aspects of sleep slow waves. Based on the results from spontaneous and artificially evoked slow waves, we offer a new hypothesis on instant slow wave homeostatic regulation. This regulation compensates for any potentially sleep-disturbing events by providing instant "delta injections" to maintain the nightly delta level, thus protecting cognitive functions located in the frontal lobe. We suggest that this double (long-term /instant) homeostasis provides double security for the frontal lobes in order to protect cognitive functions. The incorporation of reactive slow wave activity (SWA) makes sleep regulation more dynamic and provides more room for the internalization of external influences during sleep. PMID:25192672

  12. Aging and sleep in Williams syndrome: accelerated sleep deterioration and decelerated slow wave sleep decrement.

    PubMed

    Bódizs, Róbert; Gombos, Ferenc; Gerván, Patrícia; Szőcs, Katalin; Réthelyi, János M; Kovács, Ilona

    2014-12-01

    Specific developmental and aging trajectories characterize sleep electroencephalogram (EEG) of typically developing (TD) subjects. Williams syndrome (WS) is marked by sleep alterations and accelerated aging of several anatomo-functional and cognitive measures. Here we test the hypothesis of a premature aging of sleep in WS. Age-related changes of home recorded sleep EEG of 42 subjects (21 WS, 21 age- and gender matched TD subjects, age: 6-29 years) were tested by Pearson correlations and homogeneity-of-slopes analysis. Typical developmental/aging effects of sleep EEGs were observed in TD subjects. Accelerated aging in WS was confirmed by overall sleep/wake measures. Specifically, premature aging was evident in accelerated age-dependent declines in WS subjects' sleep efficiency, as well as in steeper age-related rises in wakefulness and wake after sleep onset (WASO) of the WS group. In contrast, NREM sleep-related measures indicated atypical decelerations of the developmental trends of WS subjects, characterized by the slowing down of the age-related slow wave sleep (SWS) declines mirrored by the lack of age-dependent increase in Stage 2 (S2) sleep. Age-effects in sleep EEG power spectra were not different among the groups. Objectively measured sleep disruption of subjects with WS is age-dependent and increasing with age. Moreover, these data suggest atypical pre- and postpubertal neural development in WS, with sleep/wake balance and REM sleep time indicating accelerated aging while NREM sleep composition revealing signs of an as yet unidentified, perhaps compensatory developmental delay. PMID:25178705

  13. Timing of spontaneous sleep-paralysis episodes.

    PubMed

    Girard, Todd A; Cheyne, J Allan

    2006-06-01

    The objective of this prospective naturalistic field study was to determine the distribution of naturally occurring sleep-paralysis (SP) episodes over the course of nocturnal sleep and their relation to bedtimes. Regular SP experiencers (N = 348) who had previously filled out a screening assessment for SP as well as a general sleep survey were recruited. Participants reported, online over the World Wide Web, using a standard reporting form, bedtimes and subsequent latencies of spontaneous episodes of SP occurring in their homes shortly after their occurrence. The distribution of SP episodes over nights was skewed to the first 2 h following bedtime. Just over one quarter of SP episodes occurred within 1 h of bedtime, although episodes were reported throughout the night with a minor mode around the time of normal waking. SP latencies following bedtimes were moderately consistent across episodes and independent of bedtimes. Additionally, profiles of SP latencies validated self-reported hypnagogic, hypnomesic, and hypnopompic SP categories, as occurring near the beginning, middle, and end of the night/sleep period respectively. Results are consistent with the hypothesis that SP timing is controlled by mechanisms initiated at or following sleep onset. These results also suggest that SP, rather than uniquely reflecting anomalous sleep-onset rapid eye movement (REM) periods, may result from failure to maintain sleep during REM periods at any point during the sleep period. On this view, SP may sometimes reflect the maintenance of REM consciousness when waking and SP hallucinations the continuation of dream experiences into waking life. PMID:16704578

  14. Regional Slow Waves and Spindles in Human Sleep

    PubMed Central

    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 (<1 Hz) oscillation between up and down states in cortical neurons. It is unknown whether slow oscillations are synchronous across the majority or the minority of brain regions—are they a global or local phenomenon? To examine this, we recorded simultaneously scalp EEG, intracerebral EEG, and unit firing in multiple brain regions of neurosurgical patients. We find that most sleep 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

  15. Enhancement of sleep slow waves: underlying mechanisms and practical consequences

    PubMed Central

    Bellesi, Michele; Riedner, Brady A.; Garcia-Molina, Gary N.; Cirelli, Chiara; Tononi, Giulio

    2014-01-01

    Even modest sleep restriction, especially the loss of sleep slow wave activity (SWA), is invariably associated with slower electroencephalogram (EEG) activity during wake, the occurrence of local sleep in an otherwise awake brain, and impaired performance due to cognitive and memory deficits. Recent studies not only confirm the beneficial role of sleep in memory consolidation, but also point to a specific role for sleep slow waves. Thus, the implementation of methods to enhance sleep slow waves without unwanted arousals or lightening of sleep could have significant practical implications. Here we first review the evidence that it is possible to enhance sleep slow waves in humans using transcranial direct-current stimulation (tDCS) and transcranial magnetic stimulation. Since these methods are currently impractical and their safety is questionable, especially for chronic long-term exposure, we then discuss novel data suggesting that it is possible to enhance slow waves using sensory stimuli. We consider the physiology of the K-complex (KC), a peripheral evoked slow wave, and show that, among different sensory modalities, acoustic stimulation is the most effective in increasing the magnitude of slow waves, likely through the activation of non-lemniscal ascending pathways to the thalamo-cortical system. In addition, we discuss how intensity and frequency of the acoustic stimuli, as well as exact timing and pattern of stimulation, affect sleep enhancement. Finally, we discuss automated algorithms that read the EEG and, in real-time, adjust the stimulation parameters in a closed-loop manner to obtain an increase in sleep slow waves and avoid undesirable arousals. In conclusion, while discussing the mechanisms that underlie the generation of sleep slow waves, we review the converging evidence showing that acoustic stimulation is safe and represents an ideal tool for slow wave sleep (SWS) enhancement. PMID:25389394

  16. Slow oscillations during sleep coordinate interregional communication in cortical networks.

    PubMed

    Cox, Roy; van Driel, Joram; de Boer, Marieke; Talamini, Lucia M

    2014-12-10

    Large-amplitude sleep slow oscillations group faster neuronal oscillations and are of functional relevance for memory performance. However, relatively little is known about the impact of slow oscillations on functionally coupled networks. Here, we provide a comprehensive view on how human slow oscillatory dynamics influence various measures of brain processing. We demonstrate that slow oscillations coordinate interregional cortical communication, as assessed by phase synchrony in the sleep spindle frequency range and cross-frequency coupling between spindle and beta activity. Furthermore, we show that the organizing role of slow oscillations is restricted to circumscribed topographical areas. These findings add importantly to our basic understanding of the orchestrating role of slow oscillations. In addition, they are of considerable relevance for accounts of sleep-dependent memory reprocessing and consolidation. PMID:25505340

  17. Changes in spontaneous baroreflex sensitivity during sleep in humans.

    PubMed

    Shamsuzzaman, A S; Sugiyama, Y; Okada, H; Takeuchi, S; Iwase, S; Matsukawa, T; Mano, T

    1994-01-01

    To evaluate changes in the spontaneous baroreflex sensitivity for heart rate and for muscle sympathetic nerve activity (MSNA) during sleep, we simultaneously recorded MSNA from the tibial nerve and monitored ECG, EEG, EOG, EMG and blood pressure during the resting awake stage and sleep. Blood pressure, ECG and MSNA waves were changed to equidistant time series data of each second by cubic spline interpolation. Cross correlations between the MSNA and diastolic blood pressure and between the instantaneous heart rate and systolic blood pressure were analyzed. Spontaneous baroreflex sensitivities for MSNA and for heart rate were assessed from the slope of the regression lines for each. During sleep, the spontaneous baroreflex sensitivity for MSNA gradually decreased as the non-REM sleep stages advanced. Spontaneous baroreflex sensitivity for heart rate did not show any apparent changes. These results suggest that baroreflex modulations for heart rate and for MSNA differ during sleep. PMID:12703525

  18. Enhancing Slow Wave Sleep with Sodium Oxybate Reduces the Behavioral and Physiological Impact of Sleep Loss

    PubMed Central

    Walsh, James K.; Hall-Porter, Janine M.; Griffin, Kara S.; Dodson, Ehren R.; Forst, Elizabeth H.; Curry, Denise T.; Eisenstein, Rhody D.; Schweitzer, Paula K.

    2010-01-01

    Study Objectives: To investigate whether enhancement of slow wave sleep (SWS) with sodium oxybate reduces the impact of sleep deprivation. Design: Double-blind, parallel group, placebo-controlled design Setting: Sleep research laboratory Participants: Fifty-eight healthy adults (28 placebo, 30 sodium oxybate), ages 18-50 years. Interventions: A 5-day protocol included 2 screening/baseline nights and days, 2 sleep deprivation nights, each followed by a 3-h daytime (08:00-11:00) sleep opportunity and a recovery night. Sodium oxybate or placebo was administered prior to each daytime sleep period. Multiple sleep latency test (MSLT), psychomotor vigilance test (PVT), Karolinska Sleepiness Scale (KSS), and Profile of Mood States were administered during waking hours. Measurements and Results: During daytime sleep, the sodium oxybate group had more SWS, more EEG spectral power in the 1-9 Hz range, and less REM. Mean MSLT latency was longer for the sodium oxybate group on the night following the first daytime sleep period and on the day following the second day sleep period. Median PVT reaction time was faster in the sodium oxybate group following the second day sleep period. The change from baseline in SWS was positively correlated with the change in MSLT and KSS. During recovery sleep the sodium oxybate group had less TST, SWS, REM, and slow wave activity (SWA) than the placebo group. Conclusions: Pharmacological enhancement of SWS with sodium oxybate resulted in a reduced response to sleep loss on measures of alertness and attention. In addition, SWS enhancement during sleep restriction appears to result in a reduced homeostatic response to sleep loss. Citation: Walsh JK; Hall-Porter JM; Griffin KS; Dodson ER; Forst EH; Curry DT; Eisenstein RD; Schweitzer PK. Enhancing slow wave sleep with sodium oxybate reduces the behavioral and physiological impact of sleep loss. SLEEP 2010;33(9):1217-1225. PMID:20857869

  19. The occurrence of individual slow waves in sleep is predicted by heart rate.

    PubMed

    Mensen, Armand; Zhang, Zhongxing; Qi, Ming; Khatami, Ramin

    2016-01-01

    The integration of near-infrared spectroscopy and electroencephalography measures presents an ideal method to study the haemodynamics of sleep. While the cortical dynamics and neuro-modulating influences affecting the transition from wakefulness to sleep is well researched, the assumption has been that individual slow waves, the hallmark of deep sleep, are spontaneously occurring cortical events. By creating event-related potentials from the NIRS recording, time-locked to the onset of thousands of individual slow waves, we show the onset of slow waves is phase-locked to an ongoing oscillation in the NIRS recording. This oscillation stems from the moment to moment fluctuations of light absorption caused by arterial pulsations driven by the heart beat. The same oscillating signal can be detected if the electrocardiogram is time-locked to the onset of the slow wave. The ongoing NIRS oscillation suggests that individual slow wave initiation is dependent on that signal, and not the other way round. However, the precise causal links remain speculative. We propose several potential mechanisms: that the heart-beat or arterial pulsation acts as a stimulus which evokes a down-state; local fluctuations in energy supply may lead to a network effect of hyperpolarization; that the arterial pulsations lead to corresponding changes in the cerebral-spinal-fluid which evokes the slow wave; or that a third neural generator, regulating heart rate and slow waves may be involved. PMID:27445083

  20. The occurrence of individual slow waves in sleep is predicted by heart rate

    PubMed Central

    Mensen, Armand; Zhang, Zhongxing; Qi, Ming; Khatami, Ramin

    2016-01-01

    The integration of near-infrared spectroscopy and electroencephalography measures presents an ideal method to study the haemodynamics of sleep. While the cortical dynamics and neuro-modulating influences affecting the transition from wakefulness to sleep is well researched, the assumption has been that individual slow waves, the hallmark of deep sleep, are spontaneously occurring cortical events. By creating event-related potentials from the NIRS recording, time-locked to the onset of thousands of individual slow waves, we show the onset of slow waves is phase-locked to an ongoing oscillation in the NIRS recording. This oscillation stems from the moment to moment fluctuations of light absorption caused by arterial pulsations driven by the heart beat. The same oscillating signal can be detected if the electrocardiogram is time-locked to the onset of the slow wave. The ongoing NIRS oscillation suggests that individual slow wave initiation is dependent on that signal, and not the other way round. However, the precise causal links remain speculative. We propose several potential mechanisms: that the heart-beat or arterial pulsation acts as a stimulus which evokes a down-state; local fluctuations in energy supply may lead to a network effect of hyperpolarization; that the arterial pulsations lead to corresponding changes in the cerebral-spinal-fluid which evokes the slow wave; or that a third neural generator, regulating heart rate and slow waves may be involved. PMID:27445083

  1. Involvement of Spindles in Memory Consolidation Is Slow Wave Sleep-Specific

    ERIC Educational Resources Information Center

    Cox, Roy; Hofman, Winni F.; Talamini, Lucia M.

    2012-01-01

    Both sleep spindles and slow oscillations have been implicated in sleep-dependent memory consolidation. Whereas spindles occur during both light and deep sleep, slow oscillations are restricted to deep sleep, raising the possibility of greater consolidation-related spindle involvement during deep sleep. We assessed declarative memory retention…

  2. Properties of slow oscillation during slow-wave sleep and anesthesia in cats.

    PubMed

    Chauvette, Sylvain; Crochet, Sylvain; Volgushev, Maxim; Timofeev, Igor

    2011-10-19

    Deep anesthesia is commonly used as a model of slow-wave sleep (SWS). Ketamine-xylazine anesthesia reproduces the main features of sleep slow oscillation: slow, large-amplitude waves in field potential, which are generated by the alternation of hyperpolarized and depolarized states of cortical neurons. However, direct quantitative comparison of field potential and membrane potential fluctuations during natural sleep and anesthesia is lacking, so it remains unclear how well the properties of sleep slow oscillation are reproduced by the ketamine-xylazine anesthesia model. Here, we used field potential and intracellular recordings in different cortical areas in the cat to directly compare properties of slow oscillation during natural sleep and ketamine-xylazine anesthesia. During SWS cortical activity showed higher power in the slow/delta (0.1-4 Hz) and spindle (8-14 Hz) frequency range, whereas under anesthesia the power in the gamma band (30-100 Hz) was higher. During anesthesia, slow waves were more rhythmic and more synchronous across the cortex. Intracellular recordings revealed that silent states were longer and the amplitude of membrane potential around transition between active and silent states was bigger under anesthesia. Slow waves were mostly uniform across cortical areas under anesthesia, but in SWS, they were most pronounced in associative and visual areas but smaller and less regular in somatosensory and motor cortices. We conclude that, although the main features of the slow oscillation in sleep and anesthesia appear similar, multiple cellular and network features are differently expressed during natural SWS compared with ketamine-xylazine anesthesia. PMID:22016533

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

    PubMed Central

    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

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

    PubMed

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

    2015-08-01

    Slow waves (SWs, 0.5-4Hz) 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

  5. Spontaneous neuronal burst discharges as dependent and independent variables in the maturation of cerebral cortex tissue cultured in vitro: a review of activity-dependent studies in live 'model' systems for the development of intrinsically generated bioelectric slow-wave sleep patterns.

    PubMed

    Corner, Michael A

    2008-11-01

    A survey is presented of recent experiments which utilize spontaneous neuronal spike trains as dependent and/or independent variables in developing cerebral cortex cultures when synaptic transmission is interfered with for varying periods of time. Special attention is given to current difficulties in selecting suitable preparations for carrying out biologically relevant developmental studies, and in applying spike-train analysis methods with sufficient resolution to detect activity-dependent age and treatment effects. A hierarchy of synchronized nested burst discharges which approximate early slow-wave sleep patterns in the intact organism is established as a stable basis for isolated cortex function. The complexity of reported long- and short-term homeostatic responses to experimental interference with synaptic transmission is reviewed, and the crucial role played by intrinsically generated bioelectric activity in the maturation of cortical networks is emphasized. PMID:18722470

  6. Slow waves, sharp waves, ripples, and REM in sleeping dragons.

    PubMed

    Shein-Idelson, Mark; Ondracek, Janie M; Liaw, Hua-Peng; Reiter, Sam; Laurent, Gilles

    2016-04-29

    Sleep has been described in animals ranging from worms to humans. Yet the electrophysiological characteristics of brain sleep, such as slow-wave (SW) and rapid eye movement (REM) activities, are thought to be restricted to mammals and birds. Recording from the brain of a lizard, the Australian dragon Pogona vitticeps, we identified SW and REM sleep patterns, thus pushing back the probable evolution of these dynamics at least to the emergence of amniotes. The SW and REM sleep patterns that we observed in lizards oscillated continuously for 6 to 10 hours with a period of ~80 seconds. The networks controlling SW-REM antagonism in amniotes may thus originate from a common, ancient oscillator circuit. Lizard SW dynamics closely resemble those observed in rodent hippocampal CA1, yet they originate from a brain area, the dorsal ventricular ridge, that has no obvious hodological similarity with the mammalian hippocampus. PMID:27126045

  7. Spindle activity phase-locked to sleep slow oscillations.

    PubMed

    Klinzing, Jens G; Mölle, Matthias; Weber, Frederik; Supp, Gernot; Hipp, Jörg F; Engel, Andreas K; Born, Jan

    2016-07-01

    The <1Hz slow oscillation (SO) and spindles are hallmarks of mammalian non-rapid eye movement and slow wave sleep. Spindle activity occurring phase-locked to the SO is considered a candidate mediator of memory consolidation during sleep. We used source localization of magnetoencephalographic (MEG) and electroencephalographic (EEG) recordings from 11 sleeping human subjects for an in-depth analysis of the temporal and spatial properties of sleep spindles co-occurring with SOs. Slow oscillations and spindles were identified in the EEG and related to the MEG signal, providing enhanced spatial resolution. In the temporal domain, we confirmed a phase-locking of classical 12-15Hz fast spindle activity to the depolarizing SO up-state and of 9-12Hz slow spindle activity to the up-to-down-state transition of the SO. In the spatial domain, we show a broad spread of spindle activity, with less distinct anterior-posterior separation of fast and slow spindles than commonly seen in the EEG. We further tested a prediction of current memory consolidation models, namely the existence of a spatial bias of SOs over sleep spindles as a mechanism to promote localized neuronal synchronization and plasticity. In contrast to that prediction, a comparison of SOs dominating over the left vs. right hemisphere did not reveal any signs of a concurrent lateralization of spindle activity co-occurring with these SOs. Our data are consistent with the concept of the neocortical SO exerting top-down control over thalamic spindle generation. However, they call into question the notion that SOs locally coordinate spindles and thereby inform spindle-related memory processing. PMID:27103135

  8. Developmental aspects of sleep slow waves: linking sleep, brain maturation and behavior.

    PubMed

    Ringli, Maya; Huber, Reto

    2011-01-01

    Sleep slow waves are the major electrophysiological features of non-rapid eye movement (NREM) sleep. Although there is growing understanding of where slow waves originate and how they are generated during sleep, the function of slow waves is still largely unclear. A recently proposed hypothesis relates slow waves to the homeostatic regulation of synaptic plasticity. While several studies confirm a correlation between experimentally triggered synaptic changes and slow-wave activity (SWA), little is known about its association to synaptic changes occurring during cortical maturation. Interestingly, slow waves undergo remarkable changes during development that parallel the time course of cortical maturation. In a recent cross-sectional study including children and adolescents, the topographical distribution of SWA was analyzed with high-density electroencephalography. The results showed age-dependent differences in SWA topography: SWA was highest over posterior regions during early childhood and then shifted over central derivations to the frontal cortex in late adolescence. This trajectory of SWA topography matches the course of cortical gray maturation. In this chapter, the major changes in slow waves during development are highlighted and linked to cortical maturation and behavior. Interestingly, synaptic density and slow-wave amplitude increase during childhood are highest shortly before puberty, decline thereafter during adolescence, reaching overall stable levels during adulthood. The question arises whether SWA is merely reflecting cortical changes or if it plays an active role in brain maturation. We thereby propose a model, by which sleep slow waves may contribute to cortical maturation. We hypothesize that while there is a balance between synaptic strengthening and synaptic downscaling in adults, the balance of strengthening/formation and weakening/elimination is tilted during development. PMID:21854956

  9. Development of the brain's default mode network from wakefulness to slow wave sleep.

    PubMed

    Sämann, Philipp G; Wehrle, Renate; Hoehn, David; Spoormaker, Victor I; Peters, Henning; Tully, Carolin; Holsboer, Florian; Czisch, Michael

    2011-09-01

    Falling asleep is paralleled by a loss of conscious awareness and reduced capacity to process external stimuli. Little is known on sleep-associated changes of spontaneously synchronized anatomical networks as detected by resting-state functional magnetic resonance imaging (rs-fMRI). We employed functional connectivity analysis of rs-fMRI series obtained from 25 healthy participants, covering all non-rapid eye movement (NREM) sleep stages. We focused on the default mode network (DMN) and its anticorrelated network (ACN) that are involved in internal and external awareness during wakefulness. Using independent component analysis, cross-correlation analysis (CCA), and intraindividual dynamic network tracking, we found significant changes in DMN/ACN integrity throughout the NREM sleep. With increasing sleep depth, contributions of the posterior cingulate cortex (PCC)/retrosplenial cortex (RspC), parahippocampal gyrus, and medial prefrontal cortex to the DMN decreased. CCA revealed a breakdown of corticocortical functional connectivity, particularly between the posterior and anterior midline node of the DMN and the DMN and the ACN. Dynamic tracking of the DMN from wakefulness into slow wave sleep in a single subject added insights into intraindividual network fluctuations. Results resonate with a role of the PCC/RspC for the regulation of consciousness. We further submit that preserved corticocortical synchronization could represent a prerequisite for maintaining internal and external awareness. PMID:21330468

  10. Slow brain oscillations of sleep, resting state, and vigilance.

    PubMed

    Van Someren, E J W; Van Der Werf, Y D; Roelfsema, P R; Mansvelder, H D; da Silva, F H Lopes

    2011-01-01

    The most important quest of cognitive neuroscience may be to unravel the mechanisms by which the brain selects, links, consolidates, and integrates new information into its neuronal network, while preventing saturation to occur. During the past decade, neuroscientists working within several disciplines have observed an important involvement of the specific types of brain oscillations that occur during sleep--the cortical slow oscillations; during the resting state--the fMRI resting state networks including the default-mode network (DMN); and during task performance--the performance modulations that link as well to modulations in electroencephalography or magnetoencephalography frequency content. Understanding the role of these slow oscillations thus appears to be essential for our fundamental understanding of brain function. Brain activity is characterized by oscillations occurring in spike frequency, field potentials or blood oxygen level-dependent functional magnetic resonance imaging signals. Environmental stimuli, reaching the brain through our senses, activate or inactivate neuronal populations and modulate ongoing activity. The effect they sort is to a large extent determined by the momentary state of the slow endogenous oscillations of the brain. In the absence of sensory input, as is the case during rest or sleep, brain activity does not cease. Rather, its oscillations continue and change with respect to their dominant frequencies and coupling topography. This chapter briefly introduces the topics that will be addressed in this dedicated volume of Progress in Brain Research on slow oscillations and sets the stage for excellent papers discussing their molecular, cellular, network physiological and cognitive performance aspects. Getting to know about slow oscillations is essential for our understanding of plasticity, memory, brain structure from synapse to DMN, cognition, consciousness, and ultimately for our understanding of the mechanisms and functions of

  11. REM sleep behaviour disorder is associated with lower fast and higher slow sleep spindle densities.

    PubMed

    O'Reilly, Christian; Godin, Isabelle; Montplaisir, Jacques; Nielsen, Tore

    2015-12-01

    To investigate differences in sleep spindle properties and scalp topography between patients with rapid eye movement sleep behaviour disorder (RBD) and healthy controls, whole-night polysomnograms of 35 patients diagnosed with RBD and 35 healthy control subjects matched for age and sex were compared. Recordings included a 19-lead 10-20 electroencephalogram montage and standard electromyogram, electrooculogram, electrocardiogram and respiratory leads. Sleep spindles were automatically detected using a standard algorithm, and their characteristics (amplitude, duration, density, frequency and frequency slope) compared between groups. Topological analyses of group-discriminative features were conducted. Sleep spindles occurred at a significantly (e.g. t34 = -4.49; P = 0.00008 for C3) lower density (spindles ∙ min(-1) ) for RBD (mean ± SD: 1.61 ± 0.56 for C3) than for control (2.19 ± 0.61 for C3) participants. However, when distinguishing slow and fast spindles using thresholds individually adapted to the electroencephalogram spectrum of each participant, densities smaller (31-96%) for fast but larger (20-120%) for slow spindles were observed in RBD in all derivations. Maximal differences were in more posterior regions for slow spindles, but over the entire scalp for fast spindles. Results suggest that the density of sleep spindles is altered in patients with RBD and should therefore be investigated as a potential marker of future neurodegeneration in these patients. PMID:26041532

  12. Acetazolamide for electrical status epilepticus in slow-wave sleep.

    PubMed

    Fine, Anthony L; Wirrell, Elaine C; Wong-Kisiel, Lily C; Nickels, Katherine C

    2015-09-01

    Electrical status epilepticus in slow-wave sleep (ESES) is characterized by nearly continuous spike-wave discharges during non-rapid eye movement (REM) sleep. ESES is present in Landau-Kleffner syndrome (LKS) and continuous spike and wave in slow-wave sleep (CSWS). Sulthiame has demonstrated reduction in spike-wave index (SWI) in ESES, but is not available in the United States. Acetazolamide (AZM) is readily available and has similar pharmacologic properties. Our aims were to assess the effect of AZM on SWI and clinical response in children with LKS and CSWS. Children with LKS or CSWS treated with AZM at our institution were identified retrospectively. Pre- and posttherapy electroencephalography (EEG) studies were evaluated for SWI. Parental and teacher report of clinical improvement was recorded. Six children met criteria for inclusion. Three children (50%) demonstrated complete resolution or SWI <5% after AZM. All children had improvement in clinical seizures and subjective improvement in communication skills and school performance. Five of six children had subjective improvement in hyperactivity and attention. AZM is a potentially effective therapy for children with LKS and CSWS. This study lends to the knowledge of potential therapies that can be used for these disorders, which can be challenging for families and providers. PMID:26230617

  13. Propagated infra-slow intrinsic brain activity reorganizes across wake and slow wave sleep

    PubMed Central

    Mitra, Anish; Snyder, Abraham Z; Tagliazucchi, Enzo; Laufs, Helmut; Raichle, Marcus E

    2015-01-01

    Propagation of slow intrinsic brain activity has been widely observed in electrophysiogical studies of slow wave sleep (SWS). However, in human resting state fMRI (rs-fMRI), intrinsic activity has been understood predominantly in terms of zero-lag temporal synchrony (functional connectivity) within systems known as resting state networks (RSNs). Prior rs-fMRI studies have found that RSNs are generally preserved across wake and sleep. Here, we use a recently developed analysis technique to study propagation of infra-slow intrinsic blood oxygen level dependent (BOLD) signals in normal adults during wake and SWS. This analysis reveals marked changes in propagation patterns in SWS vs. wake. Broadly, ordered propagation is preserved within traditionally defined RSNs but lost between RSNs. Additionally, propagation between cerebral cortex and subcortical structures reverses directions, and intra-cortical propagation becomes reorganized, especially in visual and sensorimotor cortices. These findings show that propagated rs-fMRI activity informs theoretical accounts of the neural functions of sleep. DOI: http://dx.doi.org/10.7554/eLife.10781.001 PMID:26551562

  14. Cortical thinning explains changes in sleep slow waves during adulthood.

    PubMed

    Dubé, Jonathan; Lafortune, Marjolaine; Bedetti, Christophe; Bouchard, Maude; Gagnon, Jean François; Doyon, Julien; Evans, Alan C; Lina, Jean-Marc; Carrier, Julie

    2015-05-20

    Sleep slow waves (SWs) change considerably throughout normal aging. In humans, SWs are generated and propagate on a structural backbone of highly interconnected cortical regions that form most of the default mode network, such as the insula, cingulate cortices, temporal lobe, parietal lobe, and medial frontal lobe. Regions in this network undergo cortical thinning and breakdown in structural and functional connectivity over the course of normal aging. In this study, we investigated how changes in cortical thickness (CT), a measure of gray matter integrity, are involved in modifications of sleep SWs during adulthood in humans. Thirty young (mean age = 23.49 years; SD = 2.79) and 33 older (mean age = 60.35 years; SD = 5.71) healthy subjects underwent a nocturnal polysomnography and T1 MRI. We show that, when controlling for age, higher SW density (nb/min of nonrapid eye movement sleep) was associated with higher CT in cortical regions involved in SW generation surrounding the lateral fissure (insula, superior temporal, parietal, middle frontal), whereas higher SW amplitude was associated with higher CT in middle frontal, medial prefrontal, and medial posterior regions. Mediation analyses demonstrated that thinning in a network of cortical regions involved in SW generation and propagation, but also in cognitive functions, explained the age-related decrease in SW density and amplitude. Altogether, our results suggest that microstructural degradation of specific cortical regions compromise SW generation and propagation in older subjects, critically contributing to age-related changes in SW oscillations. PMID:25995467

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

    PubMed

    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. PMID:27143431

  16. Midlife Decline in Declarative Memory Consolidation Is Correlated with a Decline in Slow Wave Sleep

    ERIC Educational Resources Information Center

    Backhaus, Jutta; Born, Jan; Hoeckesfeld, Ralf; Fokuhl, Sylvia; Hohagen, Fritz; Junghanns, Klaus

    2007-01-01

    Sleep architecture as well as memory function are strongly age dependent. Slow wave sleep (SWS), in particular, decreases dramatically with increasing age, starting already beyond the age of 30. SWS normally predominates during early nocturnal sleep and is implicated in declarative memory consolidation. However, the consequences of changes in…

  17. Slow oscillating transcranial direct current stimulation during sleep has a sleep-stabilizing effect in chronic insomnia: a pilot study.

    PubMed

    Saebipour, Mohammad R; Joghataei, Mohammad T; Yoonessi, Ali; Sadeghniiat-Haghighi, Khosro; Khalighinejad, Nima; Khademi, Soroush

    2015-10-01

    Recent evidence suggests that lack of slow-wave activity may play a fundamental role in the pathogenesis of insomnia. Pharmacological approaches and brain stimulation techniques have recently offered solutions for increasing slow-wave activity during sleep. We used slow (0.75 Hz) oscillatory transcranial direct current stimulation during stage 2 of non-rapid eye movement sleeping insomnia patients for resonating their brain waves to the frequency of sleep slow-wave. Six patients diagnosed with either sleep maintenance or non-restorative sleep insomnia entered the study. After 1 night of adaptation and 1 night of baseline polysomnography, patients randomly received sham or real stimulation on the third and fourth night of the experiment. Our preliminary results show that after termination of stimulations (sham or real), slow oscillatory transcranial direct current stimulation increased the duration of stage 3 of non-rapid eye movement sleep by 33 ± 26 min (P = 0.026), and decreased stage 1 of non-rapid eye movement sleep duration by 22 ± 17.7 min (P = 0.028), compared with sham. Slow oscillatory transcranial direct current stimulation decreased stage 1 of non-rapid eye movement sleep and wake time after sleep-onset durations, together, by 55.4 ± 51 min (P = 0.045). Slow oscillatory transcranial direct current stimulation also increased sleep efficiency by 9 ± 7% (P = 0.026), and probability of transition from stage 2 to stage 3 of non-rapid eye movement sleep by 20 ± 17.8% (P = 0.04). Meanwhile, slow oscillatory transcranial direct current stimulation decreased transitions from stage 2 of non-rapid eye movement sleep to wake by 12 ± 6.7% (P = 0.007). Our preliminary results suggest a sleep-stabilizing role for the intervention, which may mimic the effect of sleep slow-wave-enhancing drugs. PMID:26014344

  18. Slow wave activity and slow oscillations in sleepwalkers and controls: effects of 38 h of sleep deprivation.

    PubMed

    Perrault, Rosemarie; Carrier, Julie; Desautels, Alex; Montplaisir, Jacques; Zadra, Antonio

    2013-08-01

    Sleepwalkers have been shown to have an unusually high number of arousals from slow wave sleep and lower slow wave activity (SWA) power during the night than controls. Because sleep deprivation increases the frequency of slow wave sleep (SWS) arousals in sleepwalkers, it may also affect the expression of the homeostatic process to a greater extent than shown previously. We thus investigated SWA power as well as slow wave oscillation (SWO) density in 10 sleepwalkers and nine controls at baseline and following 38 h of sleep deprivation. There was a significant increase in SWA during participants' recovery sleep, especially during their second non-rapid eye movement (NREM) period. SWO density was similarly increased during recovery sleep's first two NREM periods. A fronto-central gradient in SWA and SWO was also present on both nights. However, no group differences were noted on any of the 2 nights on SWA or SWO. This unexpected result may be related to the heterogeneity of sleepwalkers as a population, as well as our small sample size. SWA pressure after extended sleep deprivation may also result in a ceiling effect in both sleepwalkers and controls. PMID:23398262

  19. Complementary roles of slow-wave sleep and rapid eye movement sleep in emotional memory consolidation.

    PubMed

    Cairney, Scott A; Durrant, Simon J; Power, Rebecca; Lewis, Penelope A

    2015-06-01

    Although rapid eye movement sleep (REM) is regularly implicated in emotional memory consolidation, the role of slow-wave sleep (SWS) in this process is largely uncharacterized. In the present study, we investigated the relative impacts of nocturnal SWS and REM upon the consolidation of emotional memories using functional magnetic resonance imaging (fMRI) and polysomnography (PSG). Participants encoded emotionally positive, negative, and neutral images (remote memories) before a night of PSG-monitored sleep. Twenty-four hours later, they encoded a second set of images (recent memories) immediately before a recognition test in an MRI scanner. SWS predicted superior memory for remote negative images and a reduction in right hippocampal responses during the recollection of these items. REM, however, predicted an overnight increase in hippocampal-neocortical connectivity associated with negative remote memory. These findings provide physiological support for sequential views of sleep-dependent memory processing, demonstrating that SWS and REM serve distinct but complementary functions in consolidation. Furthermore, these findings extend those ideas to emotional memory by showing that, once selectively reorganized away from the hippocampus during SWS, emotionally aversive representations undergo a comparably targeted process during subsequent REM. PMID:24408956

  20. Recovery after prolonged sleep deprivation: residual effects of slow-release caffeine on recovery sleep, sleepiness and cognitive functions.

    PubMed

    Beaumont, Maurice; Batéjat, Denise; Coste, Olivier; Doireau, Philippe; Chauffard, Françoise; Enslen, Marc; Lagarde, Didier; Pierard, Christophe

    2005-01-01

    A long work schedule often results in sleep deprivation, sleepiness, impaired performance and fatigue. We investigated the residual effects of slow-release caffeine (SRC) on sleep, sleepiness and cognitive performance during a 42-hour recovery period following a 64-hour continuous wakefulness period in 16 healthy males, according to a double-blind, randomised, placebo-controlled, crossover study. Three hundred milligrams of SRC or placebo was given twice a day at 21:00 and 9:00 during the first 48 h of wakefulness. Recovery sleep was analysed with electroencephalography (EEG) and wrist actigraphy, daytime sleepiness with continuous EEG, sleep latency tests and actigraphy and cognitive functions with computerized tests from the NATO AGARD STRES battery. Both drug groups exhibited almost the same sleep architecture with a rebound of slow-wave sleep during both recovery nights and of REM sleep during the second night. Wakefulness level and cognitive functions were similarly impaired in both groups on the first day of recovery and partially returned to baseline on the second. To conclude, SRC appears to have no unwanted side-effects on recovery sleep, wakefulness and cognitive performance after a long period of sleep deprivation and might therefore be a useful choice over other psychostimulants for a long work schedule. PMID:15627809

  1. Enhanced spontaneous oscillations in the supplementary motor area are associated with sleep-dependent offline learning of finger-tapping motor-sequence task.

    PubMed

    Tamaki, Masako; Huang, Tsung-Ren; Yotsumoto, Yuko; Hämäläinen, Matti; Lin, Fa-Hsuan; Náñez, José E; Watanabe, Takeo; Sasaki, Yuka

    2013-08-21

    Sleep is beneficial for various types of learning and memory, including a finger-tapping motor-sequence task. However, methodological issues hinder clarification of the crucial cortical regions for sleep-dependent consolidation in motor-sequence learning. Here, to investigate the core cortical region for sleep-dependent consolidation of finger-tapping motor-sequence learning, while human subjects were asleep, we measured spontaneous cortical oscillations by magnetoencephalography together with polysomnography, and source-localized the origins of oscillations using individual anatomical brain information from MRI. First, we confirmed that performance of the task at a retest session after sleep significantly increased compared with performance at the training session before sleep. Second, spontaneous δ and fast-σ oscillations significantly increased in the supplementary motor area (SMA) during post-training compared with pretraining sleep, showing significant and high correlation with the performance increase. Third, the increased spontaneous oscillations in the SMA correlated with performance improvement were specific to slow-wave sleep. We also found that correlations of δ oscillation between the SMA and the prefrontal and between the SMA and the parietal regions tended to decrease after training. These results suggest that a core brain region for sleep-dependent consolidation of the finger-tapping motor-sequence learning resides in the SMA contralateral to the trained hand and is mediated by spontaneous δ and fast-σ oscillations, especially during slow-wave sleep. The consolidation may arise along with possible reorganization of a larger-scale cortical network that involves the SMA and cortical regions outside the motor regions, including prefrontal and parietal regions. PMID:23966709

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

    PubMed Central

    Mazzotti, Diego Robles; Guindalini, Camila; Moraes, Walter André dos Santos; Andersen, Monica Levy; Cendoroglo, Maysa Seabra; Ramos, Luiz Roberto; Tufik, Sergio

    2014-01-01

    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, 1-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. PMID:25009494

  3. The dream-lag effect: Selective processing of personally significant events during Rapid Eye Movement sleep, but not during Slow Wave Sleep.

    PubMed

    van Rijn, E; Eichenlaub, J-B; Lewis, P A; Walker, M P; Gaskell, M G; Malinowski, J E; Blagrove, M

    2015-07-01

    Incorporation of details from waking life events into Rapid Eye Movement (REM) sleep dreams has been found to be highest on the night after, and then 5-7 nights after events (termed, respectively, the day-residue and dream-lag effects). In experiment 1, 44 participants kept a daily log for 10 days, reporting major daily activities (MDAs), personally significant events (PSEs), and major concerns (MCs). Dream reports were collected from REM and Slow Wave Sleep (SWS) in the laboratory, or from REM sleep at home. The dream-lag effect was found for the incorporation of PSEs into REM dreams collected at home, but not for MDAs or MCs. No dream-lag effect was found for SWS dreams, or for REM dreams collected in the lab after SWS awakenings earlier in the night. In experiment 2, the 44 participants recorded reports of their spontaneously recalled home dreams over the 10 nights following the instrumental awakenings night, which thus acted as a controlled stimulus with two salience levels, high (sleep lab) and low (home awakenings). The dream-lag effect was found for the incorporation into home dreams of references to the experience of being in the sleep laboratory, but only for participants who had reported concerns beforehand about being in the sleep laboratory. The delayed incorporation of events from daily life into dreams has been proposed to reflect REM sleep-dependent memory consolidation. However, an alternative emotion processing or emotional impact of events account, distinct from memory consolidation, is supported by the finding that SWS dreams do not evidence the dream-lag effect. PMID:25683202

  4. Memory improvement via slow-oscillatory stimulation during sleep in older adults.

    PubMed

    Westerberg, Carmen E; Florczak, Susan M; Weintraub, Sandra; Mesulam, M-Marsel; Marshall, Lisa; Zee, Phyllis C; Paller, Ken A

    2015-09-01

    We examined the intriguing but controversial idea that disrupted sleep-dependent consolidation contributes to age-related memory decline. Slow-wave activity during sleep may help strengthen neural connections and provide memories with long-term stability, in which case decreased slow-wave activity in older adults could contribute to their weaker memories. One prediction from this account is that age-related memory deficits should be reduced by artificially enhancing slow-wave activity. In young adults, applying transcranial current oscillating at a slow frequency (0.75 Hz) during sleep improves memory. Here, we tested whether this procedure can improve memory in older adults. In 2 sessions separated by 1 week, we applied either slow-oscillatory stimulation or sham stimulation during an afternoon nap in a double-blind, crossover design. Memory tests were administered before and after sleep. A larger improvement in word-pair recall and higher slow-wave activity was observed with slow-oscillatory stimulation than with sham stimulation. This is the first demonstration that this procedure can improve memory in older adults, suggesting that declarative memory performance in older adults is partly dependent on slow-wave activity during sleep. PMID:26116933

  5. Neuronal Networks in Children with Continuous Spikes and Waves during Slow Sleep

    ERIC Educational Resources Information Center

    Siniatchkin, Michael; Groening, Kristina; Moehring, Jan; Moeller, Friederike; Boor, Rainer; Brodbeck, Verena; Michel, Christoph M.; Rodionov, Roman; Lemieux, Louis; Stephani, Ulrich

    2010-01-01

    Epileptic encephalopathy with continuous spikes and waves during slow sleep is an age-related disorder characterized by the presence of interictal epileptiform discharges during at least greater than 85% of sleep and cognitive deficits associated with this electroencephalography pattern. The pathophysiological mechanisms of continuous spikes and…

  6. Odors enhance slow-wave activity in non-rapid eye movement sleep.

    PubMed

    Perl, Ofer; Arzi, Anat; Sela, Lee; Secundo, Lavi; Holtzman, Yael; Samnon, Perry; Oksenberg, Arie; Sobel, Noam; Hairston, Ilana S

    2016-05-01

    Most forms of suprathreshold sensory stimulation perturb sleep. In contrast, presentation of pure olfactory or mild trigeminal odorants does not lead to behavioral or physiological arousal. In fact, some odors promote objective and subjective measures of sleep quality in humans and rodents. The brain mechanisms underlying these sleep-protective properties of olfaction remain unclear. Slow oscillations in the electroencephalogram (EEG) are a marker of deep sleep, and K complexes (KCs) are an EEG marker of cortical response to sensory interference. We therefore hypothesized that odorants presented during sleep will increase power in slow EEG oscillations. Moreover, given that odorants do not drive sleep interruption, we hypothesized that unlike other sensory stimuli odorants would not drive KCs. To test these hypotheses we used polysomnography to measure sleep in 34 healthy subjects (19 women, 15 men; mean age 26.5 ± 2.5 yr) who were repeatedly presented with odor stimuli via a computer-controlled air-dilution olfactometer over the course of a single night. Each participant was exposed to one of four odorants, lavender oil (n = 13), vetiver oil (n = 5), vanillin (n = 12), or ammonium sulfide (n = 4), for durations of 5, 10, and 20 s every 9-15 min. Consistent with our hypotheses, we found that odor presentation during sleep enhanced the power of delta (0.5-4 Hz) and slow spindle (9-12 Hz) frequencies during non-rapid eye movement sleep. The increase was proportionate to odor duration. In addition, odor presentation did not modulate the occurrence of KCs. These findings imply a sleep-promoting olfactory mechanism that may deepen sleep through driving increased slow-frequency oscillations. PMID:26888107

  7. Slow-wave oscillations in a corticothalamic model of sleep and wake.

    PubMed

    Zhao, X; Kim, J W; Robinson, P A

    2015-04-01

    A physiologically-based corticothalamic neural field model is used to study slow wave oscillations including cortical UP and DOWN states in deep sleep by extending it to incorporate bursting dynamics of neurons in the thalamic reticular nucleus. The interplay of local bursting dynamics and network interactions produces the cortical UP and DOWN states of slow wave sleep while preserving previously verified model predictions in the wake state. Results show that EEG spectral features in wake and sleep are reproduced. The bursting is subthreshold but acts to intensify the amplitude of oscillations in slow wave sleep with deep UP/DOWN oscillations on the cortex emerging naturally. Furthermore, there is a continuous cycle between the two regimes, rather than a flip-flop between discrete states. PMID:25659479

  8. Spontaneous Low-Frequency Cerebral Hemodynamics Oscillations in Restless Legs Syndrome with Periodic Limb Movements During Sleep: A Near-Infrared Spectroscopy Study

    PubMed Central

    Byun, Jung-Ick; Lee, Gwan-Taek; Kim, Choong-Ki

    2016-01-01

    Background and Purpose Periodic limb movements (PLM) during sleep (PLMS) are associated with cortical and cardiovascular activation. Changes in cerebral hemodynamics caused by cortical activity can be measured using near-infrared spectroscopy (NIRS). We investigated oscillatory components of cerebral hemodynamics during PLM and different sleep stages in restless legs syndrome (RLS) patients with PLMS. Methods Four female RLS patients with PLMS, and four age- and sex-matched normal controls were included. PLM and sleep stages were scored using polysomnography, while the spontaneous cerebral hemodynamics was measured by NIRS. The phase and amplitude of the cerebral oxyhemoglobin concentration [HbO] and the deoxyhemoglobin concentration [Hb] low-frequency oscillations (LFOs) were evaluated during each sleep stage [waking, light sleep (LS; stages N1 and N2), slow-wave sleep (stage N3), and rapid eye movement (REM) sleep]. In RLS patients with PLMS, the cerebral hemodynamics during LS was divided into LS with and without PLM. Results The cerebral hemodynamics activity varied among the different sleep stages. There were changes in phase differences between [HbO] and [Hb] LFOs during the different sleep stages in the normal controls but not in the RLS patients with PLMS. The [HbO] and [Hb] LFO amplitudes were higher in the patient group than in controls during both LS with PLM and REM sleep. Conclusions The present study has demonstrated the presence of cerebral hemodynamics disturbances in RLS patients with PLMS, which may contribute to an increased risk of cerebrovascular events. PMID:26754783

  9. Slow sleep spindle and procedural memory consolidation in patients with major depressive disorder

    PubMed Central

    Nishida, Masaki; Nakashima, Yusaku; Nishikawa, Toru

    2016-01-01

    Introduction Evidence has accumulated, which indicates that, in healthy individuals, sleep enhances procedural memory consolidation, and that sleep spindle activity modulates this process. However, whether sleep-dependent procedural memory consolidation occurs in patients medicated for major depressive disorder remains unclear, as are the pharmacological and physiological mechanisms that underlie this process. Methods Healthy control participants (n=17) and patients medicated for major depressive disorder (n=11) were recruited and subjected to a finger-tapping motor sequence test (MST; nondominant hand) paradigm to compare the averaged scores of different learning phases (presleep, postsleep, and overnight improvement). Participants’ brain activity was recorded during sleep with 16 electroencephalography channels (between MSTs). Sleep scoring and frequency analyses were performed on the electroencephalography data. Additionally, we evaluated sleep spindle activity, which divided the spindles into fast-frequency spindle activity (12.5–16 Hz) and slow-frequency spindle activity (10.5–12.5 Hz). Result Sleep-dependent motor memory consolidation in patients with depression was impaired in comparison with that in control participants. In patients with depression, age correlated negatively with overnight improvement. The duration of slow-wave sleep correlated with the magnitude of motor memory consolidation in patients with depression, but not in healthy controls. Slow-frequency spindle activity was associated with reduction in the magnitude of motor memory consolidation in both groups. Conclusion Because the changes in slow-frequency spindle activity affected the thalamocortical network dysfunction in patients medicated for depression, dysregulated spindle generation may impair sleep-dependent memory consolidation. Our findings may help to elucidate the cognitive deficits that occur in patients with major depression both in the waking state and during sleep. PMID

  10. Slow Sleep Spindle Activity, Declarative Memory, and General Cognitive Abilities in Children

    PubMed Central

    Hoedlmoser, Kerstin; Heib, Dominik P.J.; Roell, Judith; Peigneux, Philippe; Sadeh, Avi; Gruber, Georg; Schabus, Manuel

    2014-01-01

    Study Objectives: Functional interactions between sleep spindle activity, declarative memory consolidation, and general cognitive abilities in school-aged children. Design: Healthy, prepubertal children (n = 63; mean age 9.56 ± 0.76 y); ambulatory all-night polysomnography (2 nights); investigating the effect of prior learning (word pair association task; experimental night) versus nonlearning (baseline night) on sleep spindle activity; general cognitive abilities assessed using the Wechsler Intelligence Scale for Children-IV (WISC-IV). Measurements and Results: Analysis of spindle activity during nonrapid eye movement sleep (N2 and N3) evidenced predominant peaks in the slow (11-13 Hz) but not in the fast (13-15 Hz) sleep spindle frequency range (baseline and experimental night). Analyses were restricted to slow sleep spindles. Changes in spindle activity from the baseline to the experimental night were not associated with the overnight change in the number of recalled words reflecting declarative memory consolidation. Children with higher sleep spindle activity as measured at frontal, central, parietal, and occipital sites during both baseline and experimental nights exhibited higher general cognitive abilities (WISC-IV) and declarative learning efficiency (i.e., number of recalled words before and after sleep). Conclusions: Slow sleep spindles (11-13 Hz) in children age 8–11 y are associated with inter-individual differences in general cognitive abilities and learning efficiency. Citation: Hoedlmoser K, Heib DPJ, Roell J, Peigneux P, Sadeh A, Gruber G, Schabus M. Slow sleep spindle activity, declarative memory, and general cognitive abilities in children. SLEEP 2014;37(9):1501-1512. PMID:25142558

  11. Slow wave sleep-inducing effects of first generation H1-antagonists.

    PubMed

    Saitou, K; Kaneko, Y; Sugimoto, Y; Chen, Z; Kamei, C

    1999-10-01

    The present study was performed to see if first-generation histamine H1-antagonists are useful sedative-hypnotic drugs. Increases in electroencephalogram (EEG) power spectra of the delta band (0-4 Hz) at the frontal cortex and theta band (4-8 Hz) at the hippocampus in rats were used as an indexes of sleep. The H1-antagonists used in this study resulted in a decrease in sleep latency and an increase in sleep duration (slow wave sleep). The rate of REM (rapid eye movement) sleep during slow wave sleep was decreased by H1-antagonists and brotizolam. The order of potency of H1-antagonists for the reduction in sleep latency (from greatest to least) was promethazine>chlorpheniramine>diphenhydramine and pyrilamine, and that for the increase in sleep duration was chlorpheniramine>promethazine>diphenhydramine and pyrilamine. Brotizolam was more potent than these H1-antagonists, with 14-18-fold and 4-14-fold greater effects on sleep latency and duration, respectively. These results clearly show that H1-antagonists are effective in mild to moderate insomnia as sedative-hypnotic drugs. PMID:10549859

  12. Altered Neural Responses to Sounds in Primate Primary Auditory Cortex during Slow-Wave Sleep

    PubMed Central

    Issa, Elias B.

    2011-01-01

    How sounds are processed by the brain during sleep is an important question for understanding how we perceive the sensory environment in this unique behavioral state. While human behavioral data have indicated selective impairments of sound processing during sleep, brain imaging and neurophysiology studies have reported that overall neural activity in auditory cortex during sleep is surprisingly similar to that during wakefulness. This responsiveness to external stimuli leaves open the question of how neural responses during sleep differ, if at all, from wakefulness. Using extracellular neural recordings in the primary auditory cortex of naturally sleeping common marmosets, we show that slow-wave sleep (SWS) alters neural responses in the primate auditory cortex in two specific ways. SWS reduced the sensitivity of auditory cortex such that quiet sounds elicited weak responses in SWS compared with wakefulness, while loud sounds evoked similar responses in SWS and wakefulness. Furthermore, SWS reduced the extent of sound-evoked response suppression. This pattern of alterations was not observed during rapid eye movement sleep and could not be easily explained by the presence of slow rhythms in SWS. The alteration of excitatory and inhibitory responses during SWS suggests limitations in auditory processing and provides novel insights for understanding why certain sounds are processed while others are missed during deep sleep. PMID:21414918

  13. Rats housed on corncob bedding show less slow-wave sleep.

    PubMed

    Leys, Laura J; McGaraughty, Steve; Radek, Richard J

    2012-11-01

    Despite the reported advantages of corncob bedding, questions have emerged about how comfortable animals find this type of bedding as a resting surface. In this study, encephalography (EEG) was used to compare the effects of corncob and aspen-chip bedding on rat slow-wave sleep (SWS). According to a facility-wide initiative, rats that were weaned on aspen-chip bedding were switched to corncob bedding in home cages and EEG recording chambers. Spontaneous EEG recordings obtained for 5 wk after the switch to corncob bedding demonstrated that rats spent significantly less time in SWS as compared with levels measured on aspen chips just prior to the bedding switch. SWS remained low even after a 5-wk acclimation period to the corncob bedding. We then acutely switched back to aspen-chip bedding in EEG recording chambers. Acute reinstatement of aspen-chip bedding during EEG recording was associated with an average 22% increase in time spent in SWS, with overall levels of SWS comparable to the levels measured on aspen chips prior to the change to corncob bedding. Aspen-chip bedding subsequently was reinstated in both home cages and EEG recording chambers, and SWS baseline levels were restored. These data raise important concerns about the effects of corncob bedding on rodents used in research. PMID:23294881

  14. Rats Housed on Corncob Bedding Show Less Slow-Wave Sleep

    PubMed Central

    Leys, Laura J; McGaraughty, Steve; Radek, Richard J

    2012-01-01

    Despite the reported advantages of corncob bedding, questions have emerged about how comfortable animals find this type of bedding as a resting surface. In this study, encephalography (EEG) was used to compare the effects of corncob and aspen-chip bedding on rat slow-wave sleep (SWS). According to a facility-wide initiative, rats that were weaned on aspen-chip bedding were switched to corncob bedding in home cages and EEG recording chambers. Spontaneous EEG recordings obtained for 5 wk after the switch to corncob bedding demonstrated that rats spent significantly less time in SWS as compared with levels measured on aspen chips just prior to the bedding switch. SWS remained low even after a 5-wk acclimation period to the corncob bedding. We then acutely switched back to aspen-chip bedding in EEG recording chambers. Acute reinstatement of aspen-chip bedding during EEG recording was associated with an average 22% increase in time spent in SWS, with overall levels of SWS comparable to the levels measured on aspen chips prior to the change to corncob bedding. Aspen-chip bedding subsequently was reinstated in both home cages and EEG recording chambers, and SWS baseline levels were restored. These data raise important concerns about the effects of corncob bedding on rodents used in research. PMID:23294881

  15. Dissociating the contributions of slow-wave sleep and rapid eye movement sleep to emotional item and source memory.

    PubMed

    Groch, S; Zinke, K; Wilhelm, I; Born, J

    2015-07-01

    Sleep benefits the consolidation of emotional memories, and this influence is commonly attributed to the rapid eye movement (REM) stage of sleep. However, the contributions of sleep stages to memory for an emotional episode may differ for the event per se (i.e., item memory), and the context in which it occurred (source memory). Here, we examined the effects of slow wave sleep (SWS) and REM sleep on the consolidation of emotionally negative and neutral item (picture recognition) and source memory (recall of picture-location and picture-frame color association) in humans. In Study 1, the participants (n=18) learned 48 negative and 48 neutral pictures which were presented at specific locations and preceded by colored frames that had to be associated with the picture. In a within-subject design, learning was either followed by a 3-h early-night SWS-rich or by a late-night REM sleep-rich retention interval, then retrieval was tested. Only after REM-rich sleep, and not after SWS-rich sleep, was there a significant emotional enhancement, i.e., a significantly superior retention of emotional over neutral pictures. On the other hand, after SWS-rich sleep the retention of picture-frame color associations was better than after REM-rich sleep. However, this benefit was observed only for neutral pictures; and it was completely absent for the emotional pictures. To examine whether this absent benefit reflected a suppressive effect of emotionality on associations of minor task relevance, in Study 2 we manipulated the relevance of the picture-frame color association by combining it with information about monetary reward, following otherwise comparable procedures. Here, rewarded picture-frame color associations were equally well retained over SWS-rich early sleep no matter if the frames were associated with emotional or neutral pictures. Results are consistent with the view that REM sleep favors the emotional enhancement of item memory whereas SWS appears to contribute primarily

  16. Sleep effects on slow-brain-potential reflections of associative learning.

    PubMed

    Verleger, Rolf; Ludwig, Janna; Kolev, Vasil; Yordanova, Juliana; Wagner, Ullrich

    2011-03-01

    Previous research has indicated that information acquired before sleep gets consolidated during sleep. This process of consolidation might be reflected after sleep in changed extent and topography of cortical activation during retrieval of information. Here, we designed an experiment to measure those changes by means of slow event-related EEG potentials (SPs). Retrieval of newly learnt verbal or spatial associations was tested both immediately after learning and two days later. In the night directly following immediate recall, participants either slept or stayed awake. In line with previous studies, SPs measured during retrieval from memory had parietal or left-frontal foci depending on whether the retrieved associations were spatial or verbal. However, contrary to our expectations, sleep-related consolidation did not further accentuate these content-specific topographic profiles. Rather, sleep modified SPs independently of the spatial or verbal type of learned association: SPs were reduced more after sleep than after waking specifically for those stimulus configurations that had been presented in the same combination at retrieval before sleep. The association-independent stimulus-specific effect might generally form a major component of sleep-related effects on memory. PMID:21182890

  17. Sleep's function in the spontaneous recovery and consolidation of memories.

    PubMed

    Drosopoulos, Spyridon; Schulze, Claudia; Fischer, Stefan; Born, Jan

    2007-05-01

    Building on 2 previous studies (B. R. Ekstrand, 1967; B. R. Ekstrand, M. J. Sullivan, D. F. Parker, & J. N. West, 1971), the authors present 2 experiments that were aimed at characterizing the role of retroactive interference in sleep-associated declarative memory consolidation. Using an A-B, A-C paradigm with lists of word pairs in Experiment 1, the authors showed that sleep provides recovery from retroactive interference induced at encoding, whereas no such recovery was seen in several wake control conditions. Noninterfering word-pair lists were used in Experiment 2 (A-B, C-D). Sleeping after learning, in comparison with waking after learning, enhanced retention of both lists to a similar extent when encoding was less intense because of less list repetition and briefer word-pair presentations. With intense encoding, sleep-associated improvements were not seen for either list. In combination, the results indicate that the benefit of sleep for declarative memory consolidation is greater for weaker associations, regardless of whether weak associations result from retroactive interference or poor encoding. PMID:17500644

  18. Targeted Memory Reactivation During Slow Wave Sleep Facilitates Emotional Memory Consolidation

    PubMed Central

    Cairney, Scott A.; Durrant, Simon J.; Hulleman, Johan; Lewis, Penelope A.

    2014-01-01

    Study Objectives: To investigate the mechanisms by which auditory targeted memory reactivation (TMR) during slow wave sleep (SWS) influences the consolidation of emotionally negative and neutral memories. Design: Each of 72 (36 negative, 36 neutral) picture-location associations were encoded with a semantically related sound. During a subsequent nap, half of the sounds were replayed in SWS, before picture-location recall was examined in a final test. Setting: Manchester Sleep Laboratory, University of Manchester. Participants: 15 adults (3 male) mean age = 20.40 (standard deviation ± 3.07). Interventions: TMR with auditory cues during SWS. Measurements and Results: Performance was assessed by memory accuracy and recall response times (RTs). Data were analyzed with a 2 (sound: replayed/not replayed) × 2 (emotion: negative/neutral) repeated measures analysis of covariance with SWS duration, and then SWS spindles, as the mean-centered covariate. Both analyses revealed a significant three-way interaction for RTs but not memory accuracy. Critically, SWS duration and SWS spindles predicted faster memory judgments for negative, relative to neutral, picture locations that were cued with TMR. Conclusions: TMR initiates an enhanced consolidation process during subsequent SWS, wherein sleep spindles mediate the selective enhancement of reactivated emotional memories. Citation: Cairney SA; Durrant SJ; Hulleman J; Lewis PA. Targeted memory reactivation during slow wave sleep facilitates emotional memory consolidation. SLEEP 2014;37(4):701-707. PMID:24688163

  19. Sleep's Function in the Spontaneous Recovery and Consolidation of Memories

    ERIC Educational Resources Information Center

    Drosopoulos, Spyridon; Schulze, Claudia; Fischer, Stefan; Born, Jan

    2007-01-01

    Building on 2 previous studies (B. R. Ekstrand, 1967; B. R. Ekstrand, M. J. Sullivan, D. F. Parker, & J. N. West, 1971), the authors present 2 experiments that were aimed at characterizing the role of retroactive interference in sleep-associated declarative memory consolidation. Using an A-B, A-C paradigm with lists of word pairs in Experiment 1,…

  20. Neurons of visual cortex respond to visceral stimulation during slow wave sleep.

    PubMed

    Pigarev, I N

    1994-10-01

    It is hypothesized here that the same cortical areas which process signals from exteroreceptors (visual, acoustic, etc.) in wakefulness process signals from visceral organs during sleep. To check this hypothesis, the activity of 49 neurons (hypercomplex, complex and simple, as defined by conventional visual stimulation) was recorded from visual areas V1 and V2 in chronic cats at different stages of the sleep-waking cycle. Neuronal responses to electrical stimulation of the area of stomach and small intestine (single pulses of 100-500 microA. 0.5 ms duration) were investigated. It was found that intraperitoneal stimulation delivered during slow wave sleep evoked clear excitatory responses in most simple and complex cells. In hypercomplex cells, only inhibitory responses were observed. All these responses disappeared in wakefulness. These observations are compatible with the above hypothesis. PMID:7845596

  1. Heightened Delta Power during Slow-Wave-Sleep in Patients with Rett Syndrome Associated with Poor Sleep Efficiency

    PubMed Central

    Ammanuel, Simon; Chan, Wesley C.; Adler, Daniel A.; Lakshamanan, Balaji M.; Gupta, Siddharth S.; Ewen, Joshua B.; Johnston, Michael V.; Marcus, Carole L.; Naidu, Sakkubai; Kadam, Shilpa D.

    2015-01-01

    Sleep problems are commonly reported in Rett syndrome (RTT); however the electroencephalographic (EEG) biomarkers underlying sleep dysfunction are poorly understood. The aim of this study was to analyze the temporal evolution of quantitative EEG (qEEG) biomarkers in overnight EEGs recorded from girls (2–9 yrs. old) diagnosed with RTT using a non-traditional automated protocol. In this study, EEG spectral analysis identified high delta power cycles representing slow wave sleep (SWS) in 8–9h overnight sleep EEGs from the frontal, central and occipital leads (AP axis), comparing age-matched girls with and without RTT. Automated algorithms quantitated the area under the curve (AUC) within identified SWS cycles for each spectral frequency wave form. Both age-matched RTT and control EEGs showed similar increasing trends for recorded delta wave power in the EEG leads along the antero-posterior (AP). RTT EEGs had significantly fewer numbers of SWS sleep cycles; therefore, the overall time spent in SWS was also significantly lower in RTT. In contrast, the AUC for delta power within each SWS cycle was significantly heightened in RTT and remained heightened over consecutive cycles unlike control EEGs that showed an overnight decrement of delta power in consecutive cycles. Gamma wave power associated with these SWS cycles was similar to controls. However, the negative correlation of gamma power with age (r = -.59; p<0.01) detected in controls (2–5 yrs. vs. 6–9 yrs.) was lost in RTT. Poor % SWS (i.e., time spent in SWS overnight) in RTT was also driven by the younger age-group. Incidence of seizures in RTT was associated with significantly lower number of SWS cycles. Therefore, qEEG biomarkers of SWS in RTT evolved temporally and correlated significantly with clinical severity. PMID:26444000

  2. Napping to renew learning capacity: enhanced encoding after stimulation of sleep slow oscillations.

    PubMed

    Antonenko, Daria; Diekelmann, Susanne; Olsen, Cathrin; Born, Jan; Mölle, Matthias

    2013-04-01

    As well as consolidating memory, sleep has been proposed to serve a second important function for memory, i.e. to free capacities for the learning of new information during succeeding wakefulness. The slow wave activity (SWA) that is a hallmark of slow wave sleep could be involved in both functions. Here, we aimed to demonstrate a causative role for SWA in enhancing the capacity for encoding of information during subsequent wakefulness, using transcranial slow oscillation stimulation (tSOS) oscillating at 0.75 Hz to induce SWA in healthy humans during an afternoon nap. Encoding following the nap was tested for hippocampus-dependent declarative materials (pictures, word pairs, and word lists) and procedural skills (finger sequence tapping). As compared with a sham stimulation control condition, tSOS during the nap enhanced SWA and significantly improved subsequent encoding on all three declarative tasks (picture recognition, cued recall of word pairs, and free recall of word lists), whereas procedural finger sequence tapping skill was not affected. Our results indicate that sleep SWA enhances the capacity for encoding of declarative materials, possibly by down-scaling hippocampal synaptic networks that were potentiated towards saturation during the preceding period of wakefulness. PMID:23301831

  3. Increased frontal sleep slow wave activity in adolescents with major depression

    PubMed Central

    Tesler, Noemi; Gerstenberg, Miriam; Franscini, Maurizia; Jenni, Oskar G.; Walitza, Susanne; Huber, Reto

    2015-01-01

    Sleep slow wave activity (SWA), the major electrophysiological characteristic of deep sleep, mirrors both cortical restructuring and functioning. The incidence of Major Depressive Disorder (MDD) substantially rises during the vulnerable developmental phase of adolescence, where essential cortical restructuring is taking place. The goal of this study was to assess characteristics of SWA topography in adolescents with MDD, in order to assess abnormalities in both cortical restructuring and functioning on a local level. All night high-density EEG was recorded in 15 patients meeting DSM-5 criteria for MDD and 15 sex- and age-matched healthy controls. The actual symptom severity was assessed using the Children's Depression Rating Scale—Revised (CDRS-R). Topographical power maps were calculated based on the average SWA of the first non-rapid eye movement (NREM) sleep episode. Depressed adolescents exhibited significantly more SWA in a cluster of frontal electrodes compared to controls. SWA over frontal brain regions correlated positively with the CDRS-R subscore “morbid thoughts”. Self-reported sleep latency was significantly higher in depressed adolescents compared to controls whereas sleep architecture did not differ between the groups. Higher frontal SWA in depressed adolescents may represent a promising biomarker tracing cortical regions of intense use and/or restructuring. PMID:26870661

  4. Activation of the prostaglandin system in response to sleep loss in healthy humans: Potential mediator of increased spontaneous pain

    PubMed Central

    Haack, Monika; Lee, Erin; Cohen, Daniel; Mullington, Janet M.

    2009-01-01

    Insufficient duration of sleep is a highly prevalent behavioral pattern in society that has been shown to cause an increase in spontaneous pain and sensitivity to noxious stimuli. Prostaglandins (PG), in particular PGE2, are key mediators of inflammation and pain, and we investigated whether PGE2 is a potential mediator in sleep-loss induced changes in nociceptive processing. Twenty-four participants (7 females, age 35. 17.1yrs) stayed for 7 days in the Clinical Research Center. After two baseline days, participants were randomly assigned to either three days of 88 hours of total sleep deprivation (TSD, N=15) or 8 hours of sleep per night (N=9), followed by a night of recovery sleep. Participants rated the intensity of various pain-related symptoms every two hours across waking periods on computerized visual analog scales. PGE2 was measured in 24h-urine collections during baseline and third sleep deprivation day. Spontaneous pain, including headache, muscle pain, stomach pain, generalized body pain, and physical discomfort significantly increased by 5 to 14 units on a 100-unit scale during TSD, compared to the sleep condition. Urinary PGE2 metabolite significantly increased by about 30% in TSD over sleep condition. TSD-induced increase in spontaneous pain, in particular headache and muscle pain, was significantly correlated with increase in PGE2 metabolite. Activation of the PGE2 system appears to be a potential mediator of increased spontaneous pain in response to insufficient sleep. PMID:19560866

  5. A biphasic daily pattern of slow wave activity during a two-day 90-minute sleep wake schedule.

    PubMed

    Duncan, W C; Barbato, G; Fagioli, I; Garcia-Borreguero, D; Wehr, T A

    2009-12-01

    Twenty-four hour sleep patterns were measured in six healthy male volunteers during a 90-minute short sleep-wake (SW 30:60) cycle protocol for 48 hours. Sleep pressure estimates (amount of Slow Wave Sleep [SWS], SWA, and Rate of Synchronization [RoS: the rate of SWA build-up at the beginning of the NREM period]) were compared with the 24-hour patterns of body temperature (Tb24) and sleep propensity. A moderate sleep debt was incurred over the 48 hour study as indicated by decreased levels of 24 hour sleep. On day 1, ultradian patterns of REM and SWS sleep were prominent; on day 2, more prominent were circadian patterns of REM sleep, SWS, Sleep Latency, TST and Tb24. Also on Day 2, biphasic patterns of SWA and RoS were expressed, with peaks occurring during the falling and rising limbs of Tb24. The biphasic peaks in SWA and RoS may be associated with phase-specific interactions of the circadian pacemaker with the sleep homeostat during conditions of moderate sleep pressure. Further research is needed to replicate the finding and to identify biological factors that may underlie the twelve hour pattern in SWA. PMID:20162861

  6. Antidepressant Effects of Selective Slow Wave Sleep Deprivation in Major Depression: A High-Density EEG Investigation

    PubMed Central

    Landsness, Eric C.; Goldstein, Michael R.; Peterson, Michael J.; Tononi, Giulio; Benca, Ruth M.

    2011-01-01

    Sleep deprivation can acutely reverse depressive symptoms in some patients with major depression. Because abnormalities in slow wave sleep are one of the most consistent biological markers of depression, it is plausible that the antidepressant effects of sleep deprivation are due to the effects on slow wave homeostasis. This study tested the prediction that selectively reducing slow waves during sleep (slow wave deprivation; SWD), without disrupting total sleep time, will lead to an acute reduction in depressive symptomatology. As part of a multi-night, cross-over design study, participants with major depression (non-medicated; n = 17) underwent baseline, SWD, and recovery sleep sessions, and were recorded with high-density EEG (hdEEG). During SWD, acoustic stimuli were played to suppress subsequent slow waves, without waking up the participant. The effects of SWD on depressive symptoms were assessed with both self-rated and researcher-administered scales. Participants experienced a significant decrease in depressive symptoms according to both self-rated (p = .007) and researcher-administered (p = .010) scales, while vigilance was unaffected. The reduction in depressive symptoms correlated with the overnight dissipation of fronto-central slow wave activity (SWA) on baseline sleep, the rebound in right frontal all-night SWA on recovery sleep, and the amount of REM sleep on the SWD night. In addition to highlighting the benefits of hdEEG in detecting regional changes in brain activity, these findings suggest that SWD may help to better understand the pathophysiology of depression and may be a useful tool for the neuromodulatory reversal of depressive symptomatology. PMID:21397252

  7. Sleep

    MedlinePlus

    ... sleep deprivation? What are sleep myths? What are sleep disorders? Can certain diseases/conditions disrupt sleep? What is ... sleep deprivation? What are sleep myths? What are sleep disorders? Can certain diseases/conditions disrupt sleep? What is ...

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

    PubMed Central

    Bonnefond, Mathilde; van der Meij, Roemer; Jensen, Ole; Deuker, Lorena; Elger, Christian E.; Axmacher, Nikolai; Fell, Juergen

    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 hypothesized to rely on systematic interactions between the three cardinal neuronal oscillations characterizing non-rapid-eye-movement sleep: Under global control of de- and hyperpolarizing slow oscillations (SOs), sleep spindles may cluster hippocampal ripples for a precisely timed transfer of local information to the neocortex. Here we used direct intracranial electroencephalogram (iEEG) recordings from human epilepsy patients during natural sleep to test the assumption that SOs, spindles and ripples are functionally coupled in the hippocampus. Employing cross-frequency phase-amplitude coupling analyses, we first show that spindles are modulated by the up-state of SOs. Critically, spindles were found to in turn cluster ripples in their troughs, providing fine-tuned temporal frames for the hypothesized transfer of hippocampal memory traces. PMID:26389842

  9. Reactivation of emergent task-related ensembles during slow-wave sleep after neuroprosthetic learning.

    PubMed

    Gulati, Tanuj; Ramanathan, Dhakshin S; Wong, Chelsea C; Ganguly, Karunesh

    2014-08-01

    Brain-machine interfaces can allow neural control over assistive devices. They also provide an important platform for studying neural plasticity. Recent studies have suggested that optimal engagement of learning is essential for robust neuroprosthetic control. However, little is known about the neural processes that may consolidate a neuroprosthetic skill. On the basis of the growing body of evidence linking slow-wave activity (SWA) during sleep to consolidation, we examined whether there is 'offline' processing after neuroprosthetic learning. Using a rodent model, we found that, after successful learning, task-related units specifically experienced increased locking and coherency to SWA during sleep. Moreover, spike-spike coherence among these units was substantially enhanced. These changes were not present with poor skill acquisition or after control awake periods, demonstrating the specificity of our observations to learning. Notably, the time spent in SWA predicted the performance gains. Thus, SWA appears to be involved in offline processing after neuroprosthetic learning. PMID:24997761

  10. Fragmentation of slow wave sleep after onset of complete locked-in state.

    PubMed

    Soekadar, Surjo R; Born, Jan; Birbaumer, Niels; Bensch, Michael; Halder, Sebastian; Murguialday, Ander Ramos; Gharabaghi, Alireza; Nijboer, Femke; Schölkopf, Bernhard; Martens, Suzanne

    2013-09-15

    Locked-in syndrome (LIS) as a result of brainstem lesions or progressive neurodegenerative disorders, such as amyotrophic lateral sclerosis (ALS), is a severe medical condition in which a person is fully conscious but unable to move or talk. LIS can transition into complete locked-in syndrome (CLIS) in which residual abilities to communicate through muscle twitches are entirely lost. It is unknown how CLIS affects circadian rhythm and sleep/wake patterns. Here we report a 39-year-old ALS patient who transitioned from LIS to CLIS while brain activity was continuously recorded using electrocorticography (ECoG) over one month. While we found no circadian rhythm in heart rate and body temperature, transition into CLIS was associated with increased fragmentation of slow wave sleep (SWS) across the day. Total time in SWS did not change. SWS fragmentation might reflect progressive circadian system impairment and should be considered as a factor further limiting communication capabilities in these patients. PMID:23997708

  11. Driving sleep slow oscillations by auditory closed-loop stimulation-a self-limiting process.

    PubMed

    Ngo, Hong-Viet V; Miedema, Arjan; Faude, Isabel; Martinetz, Thomas; Mölle, Matthias; Born, Jan

    2015-04-29

    The <1 Hz EEG slow oscillation (SO) is a hallmark of slow-wave sleep (SWS) and is critically involved in sleep-associated memory formation. Previous studies showed that SOs and associated memory function can be effectively enhanced by closed-loop auditory stimulation, when clicks are presented in synchrony with upcoming SO up states. However, increasing SOs and synchronized excitability also bear the risk of emerging seizure activity, suggesting the presence of mechanisms in the healthy brain that counter developing hypersynchronicity during SOs. Here, we aimed to test the limits of driving SOs through closed-loop auditory stimulation in healthy humans. Study I tested a "Driving stimulation" protocol (vs "Sham") in which trains of clicks were presented in synchrony with SO up states basically as long as an ongoing SO train was identified on-line. Study II compared Driving stimulation with a "2-Click" protocol where the maximum of stimuli delivered in a train was limited to two clicks. Stimulation was applied during SWS in the first 210 min of nocturnal sleep. Before and after sleep declarative word-pair memories were tested. Compared with the Sham control, Driving stimulation prolonged SO trains and enhanced SO amplitudes, phase-locked spindle activity, and overnight retention of word pairs (all ps < 0.05). Importantly, effects of Driving stimulation did not exceed those of 2-Click stimulation (p > 0.180), indicating the presence of a mechanism preventing the development of hypersynchronicity during SO activity. Assessment of temporal dynamics revealed a rapidly fading phase-locked spindle activity during repetitive click stimulation, suggesting that spindle refractoriness contributes to this protective mechanism. PMID:25926443

  12. Topography of Slow Sigma Power during Sleep is Associated with Processing Speed in Preschool Children

    PubMed Central

    Doucette, Margaret R.; Kurth, Salome; Chevalier, Nicolas; Munakata, Yuko; LeBourgeois, Monique K.

    2015-01-01

    Cognitive development is influenced by maturational changes in processing speed, a construct reflecting the rapidity of executing cognitive operations. Although cognitive ability and processing speed are linked to spindles and sigma power in the sleep electroencephalogram (EEG), little is known about such associations in early childhood, a time of major neuronal refinement. We calculated EEG power for slow (10–13 Hz) and fast (13.25–17 Hz) sigma power from all-night high-density electroencephalography (EEG) in a cross-sectional sample of healthy preschool children (n = 10, 4.3 ± 1.0 years). Processing speed was assessed as simple reaction time. On average, reaction time was 1409 ± 251 ms; slow sigma power was 4.0 ± 1.5 μV2; and fast sigma power was 0.9 ± 0.2 μV2. Both slow and fast sigma power predominated over central areas. Only slow sigma power was correlated with processing speed in a large parietal electrode cluster (p < 0.05, r ranging from −0.6 to −0.8), such that greater power predicted faster reaction time. Our findings indicate regional correlates between sigma power and processing speed that are specific to early childhood and provide novel insights into the neurobiological features of the EEG that may underlie developing cognitive abilities. PMID:26556377

  13. Mild Airflow Limitation during N2 Sleep Increases K-complex Frequency and Slows Electroencephalographic Activity

    PubMed Central

    Nguyen, Chinh D.; Wellman, Andrew; Jordan, Amy S.; Eckert, Danny J.

    2016-01-01

    Study Objectives: To determine the effects of mild airflow limitation on K-complex frequency and morphology and electroencephalogram (EEG) spectral power. Methods: Transient reductions in continuous positive airway pressure (CPAP) during stable N2 sleep were performed to induce mild airflow limitation in 20 patients with obstructive sleep apnea (OSA) and 10 healthy controls aged 44 ± 13 y. EEG at C3 and airflow were measured in 1-min windows to quantify K-complex properties and EEG spectral power immediately before and during transient reductions in CPAP. The frequency and morphology (amplitude and latency of P200, N550 and N900 components) of K-complexes and EEG spectral power were compared between conditions. Results: During mild airflow limitation (18% reduction in peak inspiratory airflow from baseline, 0.38 ± 0.11 versus 0.31 ± 0.1 L/sec) insufficient to cause American Academy of Sleep Medicine-defined cortical arousal, K-complex frequency (9.5 ± 4.5 versus 13.7 ± 6.4 per min, P < 0.01), N550 amplitude (25 ± 3 versus 27 ± 3 μV, P < 0.01) and EEG spectral power (delta: 147 ± 48 versus 230 ± 99 μV2, P < 0.01 and theta bands: 31 ± 14 versus 34 ± 13 μV2, P < 0.01) significantly increased whereas beta band power decreased (14 ± 5 versus 11 ± 4 μV2, P < 0.01) compared to the preceding non flow-limited period on CPAP. K-complex frequency, morphology, and timing did not differ between patients and controls. Conclusion: Mild airflow limitation increases K-complex frequency, N550 amplitude, and spectral power of delta and theta bands. In addition to providing mechanistic insight into the role of mild airflow limitation on K-complex characteristics and EEG activity, these findings may have important implications for respiratory conditions in which airflow limitation during sleep is common (e.g., snoring and OSA). Citation: Nguyen CD, Wellman A, Jordan AS, Eckert DJ. Mild airflow limitation during N2 sleep increases k-complex frequency and slows

  14. Axonal conduction slowing induced by spontaneous bursting activity in cortical neurons cultured in a microtunnel device.

    PubMed

    Shimba, Kenta; Sakai, Koji; Isomura, Takuya; Kotani, Kiyoshi; Jimbo, Yasuhiko

    2015-01-01

    Recently, axons have been recognized as computational units in neuronal networks that can change their conduction properties along with their firing. However, little is known about the relationship between spontaneous activity and changes in the conduction velocity due to lack of a suitable method. Here, we studied changes in the conduction velocity during bursting activity using a new microfabricated device and the spike sorting method. The propagating action potentials were recorded from axons, which extended through a microtunnel in our device, comprised of a microfabricated chamber and a microelectrode array. By using waveforms recorded from a series of three electrodes along the bottom of a microtunnel, we achieved a sorting accuracy approximately 8.0% higher than that of the conventional one-electrode waveform method. We then demonstrated for the first time that conduction delays increased by 8.0% in action potentials of a mathematically isolated axon during one burst recorded at 10 days in vitro (DIV). Moreover, 79.4% of all clusters showed this conduction slowing during bursting activity at 10 DIV. Finally, we evaluated the days-in-culture dependence of the properties of bursting activity. These results suggest that our method is suitable for evaluating changes in conduction properties induced by spontaneous activity. PMID:25418582

  15. Sustained Use of CPAP Slows Deterioration of Cognition, Sleep, and Mood in Patients with Alzheimer's Disease and Obstructive Sleep Apnea: A Preliminary Study

    PubMed Central

    Cooke, Jana R.; Ayalon, Liat; Palmer, Barton W.; Loredo, Jose S.; Corey-Bloom, Jody; Natarajan, Loki; Liu, Lianqi; Ancoli-Israel, Sonia

    2009-01-01

    Introduction: Obstructive sleep apnea (OSA) is common among patients with Alzheimer's disease (AD). Untreated OSA exacerbates the cognitive and functional deficits. Continuous positive airway pressure (CPAP) has recently been shown to have beneficial effects on cognition in AD. Little attention has focused on the long-term benefits of CPAP in these patients. Methods: This was an exploratory study of sustained CPAP use (mean use = 13.3 months, SD = 5.2) among a subset of participants from an initial 6-week randomized clinical trial (RCT) of CPAP in patients with mild to moderate AD. Follow-up included 5 patients who continued CPAP (CPAP+) after completion of the RCT and 5 patients who discontinued CPAP (CPAP−), matched by time of completion of the initial study. A neuropsychological test battery and sleep/mood questionnaires were administered and effect sizes were calculated. Results: Even with a small sample size, sustained CPAP use resulted in moderate-to-large effect sizes. Compared to the CPAP− group, the CPAP+ group showed less cognitive decline with sustained CPAP use, stabilization of depressive symptoms and daytime somnolence, and significant improvement in subjective sleep quality. Caregivers of the CPAP+ group also reported that their own sleep was better when compared to the final RCT visit and that their patients psychopathological behavior was improved. Conclusion: The results of this preliminary study raise the possibility that sustained, long-term CPAP treatment for patients with AD and OSA may result in lasting improvements in sleep and mood as well as a slowing of cognitive deterioration. Prospective randomized controlled research trials evaluating these hypotheses are needed. Citation: Cooke JR; Ayalon L; Palmer BW; Loredo JS; Corey-Bloom J; Natarajan L; Liu L; Ancoli-Israel S. Sustained use of CPAP slows deterioration of cognition, sleep, and mood in patients with Alzheimer's disease and obstructive sleep apnea: a preliminary study. J Clin

  16. Sustained increase in hippocampal sharp-wave ripple activity during slow-wave sleep after learning

    PubMed Central

    Eschenko, Oxana; Ramadan, Wiâm; Mölle, Matthias; Born, Jan; Sara, Susan J.

    2008-01-01

    High-frequency oscillations, known as sharp-wave/ripple (SPW-R) complexes occurring in hippocampus during slow-wave sleep (SWS), have been proposed to promote synaptic plasticity necessary for memory consolidation. We recorded sleep for 3 h after rats were trained on an odor-reward association task. Learning resulted in an increased number SPW-Rs during the first hour of post-learning SWS. The magnitude of ripple events and their duration were also elevated for up to 2 h after the newly formed memory. Rats that did not learn the discrimination during the training session did not show any change in SPW-Rs. Successful retrieval from remote memory was likewise accompanied by an increase in SPW-R density and magnitude, relative to the previously recorded baseline, but the effects were much shorter lasting and did not include increases in ripple duration and amplitude. A short-lasting increase of ripple activity was also observed when rats were rewarded for performing a motor component of the task only. There were no increases in ripple activity after habituation to the experimental environment. These experiments show that the characteristics of hippocampal high-frequency oscillations during SWS are affected by prior behavioral experience. Associative learning induces robust and sustained (up to 2 h) changes in several SPW-R characteristics, while after retrieval from remote memory or performance of a well-trained procedural aspect of the task, only transient changes in ripple density were induced. PMID:18385477

  17. Regional scalp EEG slow-wave synchronization during sleep cyclic alternating pattern A1 subtypes.

    PubMed

    Ferri, Raffaele; Rundo, Francesco; Bruni, Oliviero; Terzano, Mario G; Stam, Cornelis J

    2006-09-01

    The levels of EEG synchronization, in the 0.25-2.5 Hz band, during the A1 subtypes of the sleep "cyclic alternating pattern" (CAP) were measured in five healthy subjects by means of the synchronization likelihood (SL) algorithm. SL was measured for seven electrode pairs (F4-F3, C4-C3, P4-P3 for the analysis of interhemispheric SL and F4-C4, C4-P4, F3-C3, and C3-P3, for the analysis of intrahemispheric SL). During the A1 CAP subtypes, SL tended to be highest between pairs of electrodes situated over different hemispheres; in particular, SL obtained from F4-F3 was the highest, followed by that of P4-P3. These results indicate that the transient high level of synchronization in the slow-wave EEG range, during the sleep A1 CAP subtypes, is a phenomenon involving mostly the anterior parts of the brain and is probably based on interhemispheric interactions, possibly mediated by transcallosal connections. PMID:16806696

  18. Electroencephalogram slowing predicts neurodegeneration in rapid eye movement sleep behavior disorder.

    PubMed

    Rodrigues Brazète, Jessica; Gagnon, Jean-François; Postuma, Ronald B; Bertrand, Josie-Anne; Petit, Dominique; Montplaisir, Jacques

    2016-01-01

    A large proportion of patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) develop a synucleinopathy, mostly Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Therefore, identifying markers of neurodegeneration in iRBD could have major implications. We aimed to assess the usefulness of electroencephalography (EEG) spectral analysis performed during wakefulness for predicting the development of a neurodegenerative disease in iRBD. Fifty-four iRBD patients, 28 of whom developed Parkinson's disease, multiple system atrophy, or dementia with Lewy bodies (mean follow-up: 3.5 years), and 30 healthy controls underwent at baseline a resting-state waking EEG recording, neurological exam, and neuropsychological assessment. Absolute and relative spectral powers were analyzed for 5 frequency bands in frontal, central, parietal, temporal, and occipital regions. The slow-to-fast [(δ + θ)/(β1 + β2)] power ratio for each of the 5 cortical regions and the dominant occipital frequency were calculated as an index of cortical slowing. Patients who developed disease showed higher absolute delta and theta power in all 5 cortical regions compared to disease-free patients and controls. The slow-to-fast power ratio was higher in all regions in patients who developed disease than in the 2 other groups. Moreover, patients who developed disease had a slower dominant occipital frequency compared to controls. The only significant difference observed between disease-free iRBD patients and controls was higher absolute delta power in frontal and occipital regions in iRBD patients. Specific EEG abnormalities were identified during wakefulness in iRBD patients who later developed a synucleinopathy. EEG slowing is a promising marker of neurodegeneration in iRBD patients. PMID:26545633

  19. Long-term history and immediate preceding state affect EEG slow wave characteristics at NREM sleep onset in C57BL/6 mice.

    PubMed

    Cui, N; Mckillop, L E; Fisher, S P; Oliver, P L; Vyazovskiy, V V

    2014-01-01

    The dynamics of cortical activity across the 24-h day and at vigilance state transitions is regulated by an interaction between global subcortical neuromodulatory influences and local shifts in network synchrony and excitability. To address the role of long-term and immediate preceding history in local and global cortical dynamics, we investigated cortical EEG recorded from both frontal and occipital regions during an undisturbed 24-h recording in mice. As expected, at the beginning of the light period, under physiologically increased sleep pressure, EEG slow waves were more frequent and had higher amplitude and slopes, compared to the rest of the light period. Within discrete NREM sleep episodes, the incidence, amplitude and slopes of individual slow waves increased progressively after episode onset in both derivations by approximately 10-30%. Interestingly, at the beginning of NREM sleep episodes slow waves in the frontal and occipital derivations frequently occurred in isolation, as quantified by longer latencies between consecutive slow waves in the two regions. Notably, slow waves during the initial period of NREM sleep following REM sleep episodes were significantly less frequent, lower in amplitude and exhibited shallower slopes, compared to those that occurred in NREM episodes after prolonged waking. Moreover, the latencies between consecutive frontal and occipital NREM slow waves were substantially longer when they occurred directly after REM sleep compared to following consolidated wakefulness. Overall these data reveal a complex picture, where both time of day and preceding state contribute to the characteristics and dynamics of slow waves within NREM sleep. These findings suggest that NREM sleep initiates in a more "local" fashion when it occurs following REM sleep episodes as opposed to sustained waking bouts. While the mechanisms and functional significance of such a re-setting of brain state after individual REM sleep episodes remains to be

  20. Scale-Free Fluctuations in Behavioral Performance: Delineating Changes in Spontaneous Behavior of Humans with Induced Sleep Deficiency

    PubMed Central

    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. PMID:25222128

  1. [General statistical characteristics of the background firing in cat's cortical neurons during slow-wave sleep].

    PubMed

    Bibikov, N G; Pigarev, I N

    2013-03-01

    Background activity of 62 neurons in cat cerebral cortex was recorded in the state of slow-wave sleep for evaluation of the firing statistics. In according to their statistical characteristics neurons were subdivided in three groups. In the first group deviation from the Poisson process were comparatively small, and revealed as fragments of increased excitability following immediately after the refractory period. Second group demonstrated positive correlation of the neighbouring interspike intervals what was conditioned by the changes of the mean firing rate. In these neurons the number of spikes included into the bursts reduced after random permutation of the interspike intervals. The third group was characterized by the big number of spikes included into the bursts (> 15%), and number of bursts usually dropped down after random permutation. Some neurons of this group had constant interspike intervals within the bursts while in other units these intervals monotonically increased toward the end of the burst. Only limited number of neurons demonstrated maximums of the autocorrelation function corresponded to the frequency of the EEG delta activity. PMID:23789438

  2. Characteristics and Management of Children with Continuous Spikes and Waves during Slow Sleep.

    PubMed

    Fatema, K; Rahman, M M; Begum, S

    2015-10-01

    This study was done to describe the clinical spectrum, EEG characteristics and treatment modalities in children with continuous spike and slow wave in sleep (CSWS). Ten patients with CSWS had been treated between 2012 and 2013. Mean age of the patients was 6.9 years; male female ratio was 3:2. The main etiologic group in this study was epilepsy (10), cerebral palsy (3) and brain lesion (arachnoid cyst). All the patients had prior seizure. Presenting features were abnormal behavior (4), agitation (4), aggression (4), eye blinking (2) and involuntary movement (2). Three patients had speech regression and 1 had motor regression. Regarding EEG finding, 7 out 10 cases had SWI>85% whereas, rest of them had SWI 50 to 80%. Most of the patients were resistant to two or more oral AED. The AED found to be efficacious were Midazolam drip, pulse methyl prednisolone and valproate. Eighty percent (80%) patient responded to midazolam drip. Methyl prednisolone caused 50% improvement in one patient but failed in 2 cases. In contrast to the previous studies where high dose valproic acid, levetiracetam, Injection ACTH was more efficacious, this study demonstrates significant positive result with midazolam drip. PMID:26620024

  3. Slow oscillating transcranial direct current stimulation during non-rapid eye movement sleep improves behavioral inhibition in attention-deficit/hyperactivity disorder

    PubMed Central

    Munz, Manuel T.; Prehn-Kristensen, Alexander; Thielking, Frederieke; Mölle, Matthias; Göder, Robert; Baving, Lioba

    2015-01-01

    Background: Behavioral inhibition, which is a later-developing executive function (EF) and anatomically located in prefrontal areas, is impaired in attention-deficit and hyperactivity disorder (ADHD). While optimal EFs have been shown to depend on efficient sleep in healthy subjects, the impact of sleep problems, frequently reported in ADHD, remains elusive. Findings of macroscopic sleep changes in ADHD are inconsistent, but there is emerging evidence for distinct microscopic changes with a focus on prefrontal cortical regions and non-rapid eye movement (non-REM) slow-wave sleep. Recently, slow oscillations (SO) during non-REM sleep were found to be less functional and, as such, may be involved in sleep-dependent memory impairments in ADHD. Objective:By augmenting slow-wave power through bilateral, slow oscillating transcranial direct current stimulation (so-tDCS, frequency = 0.75 Hz) during non-REM sleep, we aimed to improve daytime behavioral inhibition in children with ADHD. Methods: Fourteen boys (10–14 years) diagnosed with ADHD were included. In a randomized, double-blind, cross-over design, patients received so-tDCS either in the first or in the second experimental sleep night. Inhibition control was assessed with a visuomotor go/no-go task. Intrinsic alertness was assessed with a simple stimulus response task. To control for visuomotor performance, motor memory was assessed with a finger sequence tapping task. Results: SO-power was enhanced during early non-REM sleep, accompanied by slowed reaction times and decreased standard deviations of reaction times, in the go/no-go task after so-tDCS. In contrast, intrinsic alertness, and motor memory performance were not improved by so-tDCS. Conclusion: Since behavioral inhibition but not intrinsic alertness or motor memory was improved by so-tDCS, our results suggest that lateral prefrontal slow oscillations during sleep might play a specific role for executive functioning in ADHD. PMID:26321911

  4. Phase coupling between rhythmic slow activity and gamma characterizes mesiotemporal rapid-eye-movement sleep in humans.

    PubMed

    Clemens, Z; Weiss, B; Szucs, A; Eross, L; Rásonyi, G; Halász, P

    2009-09-29

    In the human sleep literature there is much controversy regarding the existence and the characteristics of hippocampal rhythmic slow activity (RSA). Generally the human RSA is believed to occur in short bursts of theta activity. An earlier study, however, reported mesiotemporal RSA during rapid-eye-movement (REM) sleep that instead of theta fell in the delta frequency band. We conjectured that if this RSA activity is indeed a human analogue of the animal hippocampal theta then characteristics associated with the animal theta should also be reflected in the human recordings. Here our aim was to examine possible phase coupling between mesiotemporal RSA and gamma activity during REM sleep. The study relied on nine epilepsy surgery candidates implanted with foramen ovale electrodes. Positive half-waves of the 1.5-3 Hz RSA were identified by an automatic algorithm during REM sleep. High-frequency activity was assessed for 11 consecutive 20 Hz-wide frequency bands between 20 and 240 Hz. Increase in high frequency activity was phase coupled with RSA in most frequency bands and patients. Such a phase coupling closely resembles that seen between theta and gamma in rodents. We consider this commonality to be an additional reason for regarding delta rather than theta as the human analogue of RSA in animals. PMID:19555738

  5. Effects of a new slow release formulation of caffeine on EEG, psychomotor and cognitive functions in sleep-deprived subjects.

    PubMed

    Patat, Alain; Rosenzweig, Pierre; Enslen, Marc; Trocherie, Suzanne; Miget, Nathalie; Bozon, Marie-Christine; Allain, Hervé; Gandon, Jean-Marc

    2000-04-01

    Caffeine is a widely-consumed psychoactive substance whose stimulant effects on mood, attention and performance are largely recognised. The central nervous system pharmacodynamic profile of a single oral dose of a new slow release (SR) caffeine formulation (600 mg) was assessed in a randomised, double-blind, crossover, placebo-controlled study. Twelve young, health, male, sleep-deprived (for 36 h) subjects were studied using EEG and various measures of psychomotor and cognitive functions, including critical flicker fusion (CFF), choice reaction task (CRT), tracking, continuous performance task (CPT), Stroop test, body sway and subjective evaluation (Stanford Sleepiness Scale). Caffeine significantly ( < 0/05) antagonised the detrimental effects of sleep-deprivation on EEG (i.e. produced a significant decrease in delta and theta relative power and a significant increase in alpha and beta (12-40 Hz) relative power) and psychomotor performance (significant increase in speed of reaction on the CRT and Stroop tests, significant decrease in body sway, significant increase in accuracy of the CPT and significant reduction in subjective sedation) compared to placebo. The effect peaked 4 h after dosing and was maintained until the end of sleep deprivation (i.e. 24 h after dosing). In conclusion, the present results demonstrate that a single dose of caffeine SR possesses alerting effects which are able to reverse the deleterious effect of 36 h sleep deprivation for at least 24 h. Copyright 2000 John Wiley & Sons, Ltd. PMID:12404329

  6. Sharp wave-associated synchronized inputs from the piriform cortex activate olfactory tubercle neurons during slow-wave sleep

    PubMed Central

    Narikiyo, Kimiya; Manabe, Hiroyuki

    2013-01-01

    During slow-wave sleep, anterior piriform cortex neurons show highly synchronized discharges that accompany olfactory cortex sharp waves (OC-SPWs). The OC-SPW-related synchronized activity of anterior piriform cortex neurons travel down to the olfactory bulb and is thought to be involved in the reorganization of bulbar neuronal circuitry. However, influences of the OC-SPW-related activity on other regions of the central olfactory system are still unknown. Olfactory tubercle is an area of OC and part of ventral striatum that plays a key role in reward-directed motivational behaviors. In this study, we show that in freely behaving rats, olfactory tubercle receives OC-SPW-associated synchronized inputs during slow-wave sleep. Local field potentials in the olfactory tubercle showed SPW-like activities that were in synchrony with OC-SPWs. Single-unit recordings showed that a subpopulation of olfactory tubercle neurons discharged in synchrony with OC-SPWs. Furthermore, correlation analysis of spike activity of anterior piriform cortex and olfactory tubercle neurons revealed that the discharges of anterior piriform cortex neurons tended to precede those of olfactory tubercle neurons. Current source density analysis in urethane-anesthetized rats indicated that the current sink of the OC-SPW-associated input was located in layer III of the olfactory tubercle. These results indicate that OC-SPW-associated synchronized discharges of piriform cortex neurons travel to the deep layer of the olfactory tubercle and drive discharges of olfactory tubercle neurons. The entrainment of olfactory tubercle neurons in the OC-SPWs suggests that OC-SPWs coordinate reorganization of neuronal circuitry across wide areas of the central olfactory system including olfactory tubercle during slow-wave sleep. PMID:24108798

  7. Substance P and the neurokinin-1 receptor regulate electroencephalogram non-rapid eye movement sleep slow-wave activity locally

    PubMed Central

    Zielinski, Mark R.; Karpova, Svetlana A.; Yang, Xiaomei; Gerashchenko, Dmitry

    2014-01-01

    The neuropeptide substance P is an excitatory neurotransmitter produced by various cells including neurons and microglia that is involved in regulating inflammation and cerebral blood flow—functions that affect sleep and slow-wave activity (SWA). Substance P is the major ligand for the neurokinin-1 receptor (NK-1R), which is found throughout the brain including the cortex. The NK-1R is found on sleep-active cortical neurons expressing neuronal nitric oxide synthase whose activity is associated with SWA. We determined the effects of local cortical administration of a NK-1R agonist (substance P-fragment 1, 7) and a NK-1R antagonist (CP96345) on sleep and SWA in mice. The NK-1R agonist significantly enhanced SWA for several hours when applied locally to the cortex of the ipsilateral hemisphere as the electroencephalogram (EEG) electrode but not after application to the contralateral hemisphere when compared to saline vehicle control injections. In addition, a significant compensatory reduction in SWA was found after the NK-1R agonist-induced enhancements in SWA. Conversely, injections of the NK-1R antagonist into the cortex of the ipsilateral hemisphere of the EEG electrode attenuated SWA compared to vehicle injections but this effect was not found after injections of the NK-1R antagonist into contralateral hemisphere as the EEG electrode. Non-rapid eye movement sleep and rapid eye movement sleep duration responses after NK-1R agonist and antagonist injections were not significantly different from the responses to the vehicle. Our findings indicate that the substance P and the NK-1R are involved in regulating SWA locally. PMID:25301750

  8. Sex Chromosomes Regulate Nighttime Sleep Propensity during Recovery from Sleep Loss in Mice

    PubMed Central

    Pinckney, Lennisha; Paul, Ketema N.

    2013-01-01

    Sex differences in spontaneous sleep amount are largely dependent on reproductive hormones; however, in mice some sex differences in sleep amount during the active phase are preserved after gonadectomy and may be driven by non-hormonal factors. In this study, we sought to determine whether or not these sex differences are driven by sex chromosome complement. Mice from the four core genotype (FCG) mouse model, whose sex chromosome complement (XY, XX) is independent of phenotype (male or female), were implanted with electroencephalographic (EEG) and electromyographic (EMG) electrodes for the recording of sleep-wake states and underwent a 24-hr baseline recording followed by six hours of forced wakefulness. During baseline conditions in mice whose gonads remained intact, males had more total sleep and non-rapid eye movement sleep than females during the active phase. Gonadectomized FCG mice exhibited no sex differences in rest-phase sleep amount; however, during the mid-active-phase (nighttime), XX males had more spontaneous non-rapid eye movement (NREM) sleep than XX females. The XY mice did not exhibit sex differences in sleep amount. Following forced wakefulness there was a change in the factors regulating sleep. XY females slept more during their mid-active phase siestas than XX females and had higher NREM slow wave activity, a measure of sleep propensity. These findings suggest that the process that regulates sleep propensity is sex-linked, and that sleep amount and sleep propensity are regulated differently in males and females following sleep loss. PMID:23658713

  9. Pediatric sleep apnea

    MedlinePlus

    Sleep apnea - pediatric; Apnea - pediatric sleep apnea syndrome; Sleep-disordered breathing - pediatric ... Untreated pediatric sleep apnea may lead to: High blood pressure Heart or lung problems Slow growth and development

  10. Nonlinear Dynamical Systems Effects of Homeopathic Remedies on Multiscale Entropy and Correlation Dimension of Slow Wave Sleep EEG in Young Adults with Histories of Coffee-Induced Insomnia

    PubMed Central

    Bell, Iris R.; Howerter, Amy; Jackson, Nicholas; Aickin, Mikel; Bootzin, Richard R.; Brooks, Audrey J.

    2012-01-01

    Background Investigators of homeopathy have proposed that nonlinear dynamical systems (NDS) and complex systems science offer conceptual and analytic tools for evaluating homeopathic remedy effects. Previous animal studies demonstrate that homeopathic medicines alter delta electroencephalographic (EEG) slow wave sleep. The present study extended findings of remedy-related sleep stage alterations in human subjects by testing the feasibility of using two different NDS analytic approaches to assess remedy effects on human slow wave sleep EEG. Methods Subjects (N=54) were young adult male and female college students with a history of coffee-related insomnia who participated in a larger 4-week study of the polysomnographic effects of homeopathic medicines on home-based all-night sleep recordings. Subjects took one bedtime dose of a homeopathic remedy (Coffea cruda or Nux vomica 30c). We computed multiscale entropy (MSE) and the correlation dimension (Mekler-D2) for stage 3 and 4 slow wave sleep EEG sampled in artifact-free 2-minute segments during the first two rapid-eye-movement (REM) cycles for remedy and post-remedy nights, controlling for placebo and post-placebo night effects. Results MSE results indicate significant, remedy-specific directional effects, especially later in the night (REM cycle 2) (CC: remedy night increases and post-remedy night decreases in MSE at multiple sites for both stages 3 and 4 in both REM cycles; NV: remedy night decreases and post-remedy night increases, mainly in stage 3 REM cycle 2 MSE). D2 analyses yielded more sporadic and inconsistent findings. Conclusions Homeopathic medicines Coffea cruda and Nux vomica in 30c potencies alter short-term nonlinear dynamic parameters of slow wave sleep EEG in healthy young adults. MSE may provide a more sensitive NDS analytic method than D2 for evaluating homeopathic remedy effects on human sleep EEG patterns. PMID:22818237

  11. Theta-rhythmic drive between medial septum and hippocampus in slow-wave sleep and microarousal: a Granger causality analysis.

    PubMed

    Kang, D; Ding, M; Topchiy, I; Shifflett, L; Kocsis, B

    2015-11-01

    Medial septum (MS) plays a critical role in controlling the electrical activity of the hippocampus (HIPP). In particular, theta-rhythmic burst firing of MS neurons is thought to drive lasting HIPP theta oscillations in rats during waking motor activity and REM sleep. Less is known about MS-HIPP interactions in nontheta states such as non-REM sleep, in which HIPP theta oscillations are absent but theta-rhythmic burst firing in subsets of MS neurons is preserved. The present study used Granger causality (GC) to examine the interaction patterns between MS and HIPP in slow-wave sleep (SWS, a nontheta state) and during its short interruptions called microarousals (a transient theta state). We found that during SWS, while GC revealed a unidirectional MS→HIPP influence over a wide frequency band (2-12 Hz, maximum: ∼8 Hz), there was no theta peak in the hippocampal power spectra, indicating a lack of theta activity in HIPP. In contrast, during microarousals, theta peaks were seen in both MS and HIPP power spectra and were accompanied by bidirectional GC with MS→HIPP and HIPP→MS theta drives being of equal magnitude. Thus GC in a nontheta state (SWS) vs. a theta state (microarousal) primarily differed in the level of HIPP→MS. The present findings suggest a modification of our understanding of the role of MS as the theta generator in two regards. First, a MS→HIPP theta drive does not necessarily induce theta field oscillations in the hippocampus, as found in SWS. Second, HIPP theta oscillations entail bidirectional theta-rhythmic interactions between MS and HIPP. PMID:26354315

  12. Brain-wide slowing of spontaneous alpha rhythms in mild cognitive impairment

    PubMed Central

    Garcés, Pilar; Vicente, Raul; Wibral, Michael; Pineda-Pardo, Jose Ángel; López, Maria Eugenia; Aurtenetxe, Sara; Marcos, Alberto; de Andrés, Maria Emiliana; Yus, Miguel; Sancho, Miguel; Maestú, Fernando; Fernández, Alberto

    2013-01-01

    The neurophysiological changes associated with Alzheimer's Disease (AD) and Mild Cognitive Impairment (MCI) include an increase in low frequency activity, as measured with electroencephalography or magnetoencephalography (MEG). A relevant property of spectral measures is the alpha peak, which corresponds to the dominant alpha rhythm. Here we studied the spatial distribution of MEG resting state alpha peak frequency and amplitude values in a sample of 27 MCI patients and 24 age-matched healthy controls. Power spectra were reconstructed in source space with linearly constrained minimum variance beamformer. Then, 88 Regions of Interest (ROIs) were defined and an alpha peak per ROI and subject was identified. Statistical analyses were performed at every ROI, accounting for age, sex and educational level. Peak frequency was significantly decreased (p < 0.05) in MCIs in many posterior ROIs. The average peak frequency over all ROIs was 9.68 ± 0.71 Hz for controls and 9.05 ± 0.90 Hz for MCIs and the average normalized amplitude was (2.57 ± 0.59)·10−2 for controls and (2.70 ± 0.49)·10−2 for MCIs. Age and gender were also found to play a role in the alpha peak, since its frequency was higher in females than in males in posterior ROIs and correlated negatively with age in frontal ROIs. Furthermore, we examined the dependence of peak parameters with hippocampal volume, which is a commonly used marker of early structural AD-related damage. Peak frequency was positively correlated with hippocampal volume in many posterior ROIs. Overall, these findings indicate a pathological alpha slowing in MCI. PMID:24409145

  13. Exposure to extinction-associated contextual tone during slow-wave sleep and wakefulness differentially modulates fear expression.

    PubMed

    Ai, Si-Zhi; Chen, Jie; Liu, Jian-Feng; He, Jia; Xue, Yan-Xue; Bao, Yan-Ping; Han, Fang; Tang, Xiang-Dong; Lu, Lin; Shi, Jie

    2015-09-01

    Recent research has used context cues (odor or auditory cues) to target memories during sleep and has demonstrated that they can enhance declarative and procedural memories. However, the effects of external cues re-presented during sleep on emotional memory are still not fully understood. In the present study, we conducted a Pavlovian fear conditioning/extinction paradigm and examined the effects of re-exposure to extinction memory associated contextual tones during slow-wave sleep (SWS) and wakefulness on fear expression. The participants underwent fear conditioning on the first day, during which colored squares served as the conditioned stimulus (CS) and a mild shock served as the unconditioned stimulus (US). The next day, they underwent extinction, during which the CSs were presented without the US but accompanied by a contextual tone (pink noise). Immediately after extinction, the participants were required to take a nap or remain awake and randomly assigned to six groups. Four of the groups were separately exposed to the associated tone (i.e. SWS-Tone group and Wake-Tone group) or an irrelevant tone (control tone, CtrT) (i.e. SWS-CtrT group and Wake-CtrT group), while the other two groups were not (i.e. SWS-No Tone group and Wake-No Tone group). Subsequently, the conditioned responses to the CSs were tested to evaluate the fear expression. All of the participants included in the final analysis showed successful levels of fear conditioning and extinction. During the recall test, the fear responses were significantly higher in the SWS-Tone group than that in the SWS-No Tone group or the SWS-CtrT group, while the Wake-Tone group exhibited more attenuated fear responses than either the Wake-No Tone group or Wake-CtrT group. Otherwise, re-exposure to auditory tones during SWS did not affect sleep profiles. These results suggest that distinct conditions during which re-exposure to an extinction memory associated contextual cue contributes to differential effects on

  14. Short term total sleep deprivation in the rat increases antioxidant responses in multiple brain regions without impairing spontaneous alternation behavior

    PubMed Central

    Ramanathan, Lalini; Hu, Shuxin; Frautschy, Sally A.; Siegel, Jerome M.

    2009-01-01

    Total sleep deprivation (TSD) induces a broad spectrum of cognitive, behavioral and cellular changes. We previously reported that long term (5–11 days) TSD in the rat, by the disk-over-water method, decreases the activity of the antioxidant enzyme superoxide dismutase (SOD) in the brainstem and hippocampus. To gain insight into the mechanisms causing cognitive impairment, here we explore the early associations between metabolic activity, antioxidant responses and working memory (one form of cognitive impairment). Specifically we investigated the impact of short term (6 h) TSD, by gentle handling, on the levels of the endogenous antioxidant, total glutathione (GSHt), and the activities of the antioxidative enzymes, SOD and glutathione peroxidase (GPx). Short term TSD had no significant impact on SOD activity, but increased GSHt levels in the rat cortex, brainstem and basal forebrain, and GPx activity in the rat hippocampus and cerebellum. We also observed increased activity of hexokinase, (HK), the rate limiting enzyme of glucose metabolism, in the rat cortex and hypothalamus. We further showed that 6h of TSD leads to increased exploratory behavior to a new environment, without impairing spontaneous alternation behavior (SAB) in the Y maze. We conclude that acute (6h) sleep loss may trigger compensatory mechanisms (like increased antioxidant responses) that prevent initial deterioration in working memory. PMID:19850085

  15. Control of sleep-to-wake transitions via fast aminoacid and slow neuropeptide transmission

    PubMed Central

    Mosqueiro, Thiago; de Lecea, Luis; Huerta, Ramon

    2014-01-01

    The Locus Coeruleus (LC) modulates cortical, subcortical, cerebellar, brainstem and spinal cord circuits and it expresses receptors for neuromodulators that operate in a time scale of several seconds. Evidences from anatomical, electrophysiological and optogenetic experiments have shown that LC neurons receive input from a group of neurons called Hypocretins (HCRTs) that release a neuropeptide called hypocretin. It is less known how these two groups of neurons can be coregulated using GABAergic neurons. Since the time scales of GABAA inhibition is several orders of magnitude faster than the hypocretin neuropeptide effect, we investigate the limits of circuit activity regulation using a realistic model of neurons. Our investigation shows that GABAA inhibition is insufficient to control the activity levels of the LCs. Despite slower forms of GABAA can in principle work, there is not much plausibility due to the low probability of the presence of slow GABAA and lack of robust stability at the maximum firing frequencies. The best possible control mechanism predicted by our modeling analysis is the presence of inhibitory neuropeptides that exert effects in a similar time scale as the hypocretin/orexin. Although the nature of these inhibitory neuropeptides has not been identified yet, it provides the most efficient mechanism in the modeling analysis. Finally, we present a reduced mean-field model that perfectly captures the dynamics and the phenomena generated by this circuit. This investigation shows that brain communication involving multiple time scales can be better controlled by employing orthogonal mechanisms of neural transmission to decrease interference between cognitive processes and hypothalamic functions. PMID:25598695

  16. Delayed Sleep Phase Disorder In Temporal Isolation

    PubMed Central

    Campbell, Scott S.; Murphy, Patricia J.

    2007-01-01

    Study Objectives: This study sought to characterize sleep and the circadian rhythm of body core temperature of an individual with delayed sleep phase disorder (DSPD) in the absence of temporal cues and social entrainment and to compare those measures to age-matched normal control subjects studied under identical conditions. Design: Polysomnography and body temperature were recorded continuously for 4 days in entrained conditions, followed immediately by 17 days in a “free-running” environment. Setting: Temporal isolation facility in the Laboratory of Human Chronobiology, Weill Cornell Medical College. Participants: One individual who met criteria for delayed sleep phase disorder according to the International Classification of Sleep Disorders Diagnostic and Coding Manual (ICSD-2) and 3 age-matched control subjects. Interventions: None. Measurements and Results: The DSPD subject had a spontaneous period length (tau) of 25.38 hours compared to an average tau of 24.44 hours for the healthy controls. The DSPD subject also showed an altered phase relationship between sleep/wake and body temperature rhythms, as well as longer sleep latency, poorer sleep efficiency, and altered distribution of slow wave sleep (SWS) within sleep episodes, compared to control subjects. Conclusions: Delayed sleep phase disorder may be the reflection of an abnormal circadian timing system characterized not only by a long tau, but also by an altered internal phase relationship between the sleep/wake system and the circadian rhythm of body temperature. The latter results in significantly disturbed sleep, even when DSPD patients are permitted to sleep and wake at their preferred times. Citation: Campbell SS; Murphy PJ. Delayed sleep phase disorder in temporal isolation. SLEEP 2007;30(9):1225-1228. PMID:17910395

  17. Epileptic encephalopathy with continuous spikes and waves in the occipito-temporal region during slow-wave sleep in two patients with acquired Kanji dysgraphia.

    PubMed

    Kuki, Ichiro; Kawawaki, Hisashi; Okazaki, Shin; Ikeda, Hiroko; Tomiwa, Kiyotaka

    2014-12-01

    We encountered two patients with acquired Kanji dysgraphia in whom continuous spikes and waves, dominant in the occipito-temporal region, were recorded during slow-wave sleep. Electrical status epileptics during sleep (ESES) was demonstrated on overnight electroencephalography, and dipoles clustered in and around the posterior inferior temporal cortex on magnetoencephalography. Functional neuroimaging suggested dysfunction in the left posterior temporal lobe, including the posterior inferior temporal cortex. The patients had normal intelligence with no problems in reading and writing Kana, as well as copying, reading aloud, and identifying Kanjis, but showed Kanji dysgraphia (morphological, phonemic, and semantic error) accompanied by impaired visual processing. ESES was resolved by sodium valproate, clonazepam, and acetazolamide in Patient 1, and by adrenocorticotropic hormone, sodium valproate, and clorazepate in Patient 2. The present cases had the unique cognitive dysfunction of Kanji dysgraphia, which is distinct from that of Landau-Kleffner syndrome and continuous spikes and waves during slow-wave sleep. However, the present cases also share common features with these two encephalopathies in terms of the clinical course, pathophysiology, neuroimaging, and response to steroids and antiepileptic drugs. In the context of the Japanese language, acquired Kanji dysgraphia may occur due to electrical dysfunction of left posterior inferior temporal cortex in patients with ESES. PMID:25333864

  18. Adaptive immunity does not strongly suppress spontaneous tumors in a Sleeping Beauty model of cancer

    PubMed Central

    Rogers, Laura M.; Olivier, Alicia K.; Meyerholz, David K.; Dupuy, Adam J.

    2013-01-01

    The tumor immunosurveillance hypothesis describes a process by which the immune system recognizes and suppresses the growth of transformed cancer cells. A variety of epidemiological and experimental evidence supports this hypothesis. Nevertheless, there are a number of conflicting reports regarding the degree of immune protection conferred, the immune cell types responsible for protection, and the potential contributions of immunosuppressive therapies to tumor induction. The purpose of this study was to determine whether the adaptive immune system actively suppresses tumorigenesis in a Sleeping Beauty (SB) mouse model of cancer. SB transposon mutagenesis was performed in either a wild-type or immunocompromised (Rag2-null) background. Tumor latency and multiplicity were remarkably similar in both immune cohorts, suggesting that the adaptive immune system is not efficiently suppressing tumor formation in our model. Exceptions included skin tumors, which displayed increased multiplicity in wild-type animals, and leukemias, which developed with shorter latency in immune-deficient mice. Overall tumor distribution was also altered such that tumors affecting the gastrointestinal tract were more frequent and hemangiosarcomas were less frequent in immune-deficient mice compared to wild-type mice. Finally, genetic profiling of transposon-induced mutations identified significant differences in mutation prevalence for a number of genes, including Uba1. Taken together, these results indicate that B- and T-cells function to shape the genetic profile of tumors in various tumor types, despite being ineffective at clearing SB-induced tumors. This study represents the first forward genetic screen designed to examine tumor immunosurveillance mechanisms. PMID:23475219

  19. Learning-dependent, transient increase of activity in noradrenergic neurons of locus coeruleus during slow wave sleep in the rat: brain stem-cortex interplay for memory consolidation?

    PubMed

    Eschenko, Oxana; Sara, Susan J

    2008-11-01

    Memory consolidation during sleep is regaining attention due to a wave of recent reports of memory improvements after sleep or deficits after sleep disturbance. Neuromodulators have been proposed as possible players in this putative off-line memory processing, without much experimental evidence. We recorded neuronal activity in the rat noradrenergic nucleus locus coeruleus (LC) using chronically implanted movable microelectrodes while monitoring the behavioral state via electrocorticogram and online video recording. Extracellular recordings of physiologically identified noradrenergic neurons of LC were made in freely behaving rats for 3 h before and after olfactory discrimination learning. On subsequent days, if LC recording remained stable, additional learning sessions were made within the olfactory discrimination protocol, including extinction, reversals, learning new odors. Contrary to the long-standing dogma about the quiescence of noradrenergic neurons of LC, we found a transient increase in LC activity in trained rats during slow wave sleep (SWS) 2 h after learning. The discovery of learning-dependent engagement of LC neurons during SWS encourages exploration of brain stem-cortical interaction during this delayed phase of memory consolidation and should bring new insights into mechanisms underlying memory formation. PMID:18321875

  20. Transcranial slow oscillation stimulation during NREM sleep enhances acquisition of the radial maze task and modulates cortical network activity in rats

    PubMed Central

    Binder, Sonja; Rawohl, Julia; Born, Jan; Marshall, Lisa

    2014-01-01

    Slow wave sleep, hallmarked by the occurrence of slow oscillations (SO), plays an important role for the consolidation of hippocampus-dependent memories. Transcranial stimulation by weak electric currents oscillating at the endogenous SO frequency (SO-tDCS) during post-learning sleep was previously shown by us to boost SO activity and improve the consolidation of hippocampus-dependent memory in human subjects. Here, we aimed at replicating and extending these results to a rodent model. Rats were trained for 12 days at the beginning of their inactive phase in the reference memory version of the radial arm maze. In a between subjects design, animals received SO-tDCS over prefrontal cortex (PFC) or sham stimulation within a time frame of 1 h during subsequent non-rapid eye movement (NREM) sleep. Applied over multiple daily sessions SO-tDCS impacted cortical network activity as measured by EEG and behavior: at the EEG level, SO-tDCS enhanced post-stimulation upper delta (2–4 Hz) activity whereby the first stimulations of each day were preferentially affected. Furthermore, commencing on day 8, SO-tDCS acutely decreased theta activity indicating long-term effects on cortical networks. Behaviorally, working memory for baited maze arms was enhanced up to day 4, indicating enhanced consolidation of task-inherent rules, while reference memory errors did not differ between groups. Taken together, we could show here for the first time an effect of SO-tDCS during NREM sleep on cognitive functions and on cortical activity in a rodent model. PMID:24409131

  1. Control of the spontaneous emission from a single quantum dash using a slow-light mode in a two-dimensional photonic crystal on a Bragg reflector

    SciTech Connect

    Chauvin, N.; Fiore, A.; Nedel, P.; Seassal, C.; Ben Bakir, B.; Letartre, X.; Gendry, M.; Viktorovitch, P.

    2009-07-15

    We demonstrate the coupling of a single InAs/InP quantum, emitting around 1.55 {mu}m, to a slow-light mode in a two-dimensional photonic crystal on Bragg reflector. These surface addressable 2.5D photonic crystal band-edge modes present the advantages of a vertical emission and the mode area and localization may be controlled, leading to a less critical spatial alignment with the emitter. An increase in the spontaneous emission rate by a factor of 1.5-2 is measured at low temperature and is compared to the Purcell factor predicted by three-dimensional time-domain electromagnetic simulations.

  2. Randomised clinical trial of the effects of prolonged-release melatonin, temazepam and zolpidem on slow-wave activity during sleep in healthy people.

    PubMed

    Arbon, Emma L; Knurowska, Malgorzata; Dijk, Derk-Jan

    2015-07-01

    Current pharmacological treatments for insomnia include benzodiazepine and non-benzodiazepine hypnotics targeting γ-aminobutyric acid (GABA)A receptors, as well as agonists of the melatonin receptors MT1 and MT2. Melatonin, temazepam and zolpidem are thought to exert their effect through different mechanisms of action, but whether this leads to differential effects on electroencephalogram (EEG) power spectra during sleep in middle-aged people is currently not known. To establish whether the effects of prolonged-release melatonin (2 mg) on the nocturnal sleep EEG are different to those of temazepam (20 mg) and zolpidem (10 mg). Sixteen healthy men and women aged 55-64 years participated in a double-blind, placebo-controlled, four-way cross-over trial. Nocturnal sleep was assessed with polysomnography and spectral analysis of the EEG. The effects of single oral doses of prolonged-release melatonin, temazepam and zolpidem on EEG slow-wave activity (SWA, 0.75-4.5 Hz) and other frequencies during nocturnal non-rapid eye movement (NREM) sleep were compared. In an entire night analysis prolonged-release melatonin did not affect SWA, whereas temazepam and zolpidem significantly reduced SWA compared with placebo. Temazepam significantly reduced SWA compared with prolonged-release melatonin. Prolonged-release melatonin only reduced SWA during the first third of the night compared with placebo. These data show that the effects of prolonged-release melatonin on the nocturnal sleep EEG are minor and are different from those of temazepam and zolpidem; this is likely due to the different mechanisms of action of the medications. PMID:25922426

  3. Modeling aircraft noise induced sleep disturbance

    NASA Astrophysics Data System (ADS)

    McGuire, Sarah M.

    One of the primary impacts of aircraft noise on a community is its disruption of sleep. Aircraft noise increases the time to fall asleep, the number of awakenings, and decreases the amount of rapid eye movement and slow wave sleep. Understanding these changes in sleep may be important as they could increase the risk for developing next-day effects such as sleepiness and reduced performance and long-term health effects such as cardiovascular disease. There are models that have been developed to predict the effect of aircraft noise on sleep. However, most of these models only predict the percentage of the population that is awakened. Markov and nonlinear dynamic models have been developed to predict an individual's sleep structure during the night. However, both of these models have limitations. The Markov model only accounts for whether an aircraft event occurred not the noise level or other sound characteristics of the event that may affect the degree of disturbance. The nonlinear dynamic models were developed to describe normal sleep regulation and do not have a noise effects component. In addition, the nonlinear dynamic models have slow dynamics which make it difficult to predict short duration awakenings which occur both spontaneously and as a result of nighttime noise exposure. The purpose of this research was to examine these sleep structure models to determine how they could be altered to predict the effect of aircraft noise on sleep. Different approaches for adding a noise level dependence to the Markov Model was explored and the modified model was validated by comparing predictions to behavioral awakening data. In order to determine how to add faster dynamics to the nonlinear dynamic sleep models it was necessary to have a more detailed sleep stage classification than was available from visual scoring of sleep data. An automatic sleep stage classification algorithm was developed which extracts different features of polysomnography data including the

  4. From Neural Plate to Cortical Arousal—A Neuronal Network Theory of Sleep Derived from in Vitro “Model” Systems for Primordial Patterns of Spontaneous Bioelectric Activity in the Vertebrate Central Nervous System

    PubMed Central

    Corner, Michael A.

    2013-01-01

    In the early 1960s intrinsically generated widespread neuronal discharges were discovered to be the basis for the earliest motor behavior throughout the animal kingdom. The pattern generating system is in fact programmed into the developing nervous system, in a regionally specific manner, already at the early neural plate stage. Such rhythmically modulated phasic bursts were next discovered to be a general feature of developing neural networks and, largely on the basis of experimental interventions in cultured neural tissues, to contribute significantly to their morpho-physiological maturation. In particular, the level of spontaneous synchronized bursting is homeostatically regulated, and has the effect of constraining the development of excessive network excitability. After birth or hatching, this “slow-wave” activity pattern becomes sporadically suppressed in favor of sensory oriented “waking” behaviors better adapted to dealing with environmental contingencies. It nevertheless reappears periodically as “sleep” at several species-specific points in the diurnal/nocturnal cycle. Although this “default” behavior pattern evolves with development, its essential features are preserved throughout the life cycle, and are based upon a few simple mechanisms which can be both experimentally demonstrated and simulated by computer modeling. In contrast, a late onto- and phylogenetic aspect of sleep, viz., the intermittent “paradoxical” activation of the forebrain so as to mimic waking activity, is much less well understood as regards its contribution to brain development. Some recent findings dealing with this question by means of cholinergically induced “aroused” firing patterns in developing neocortical cell cultures, followed by quantitative electrophysiological assays of immediate and longterm sequelae, will be discussed in connection with their putative implications for sleep ontogeny. PMID:24961426

  5. Sleep for cognitive enhancement

    PubMed Central

    Diekelmann, Susanne

    2014-01-01

    Sleep is essential for effective cognitive functioning. Loosing even a few hours of sleep can have detrimental effects on a wide variety of cognitive processes such as attention, language, reasoning, decision making, learning and memory. While sleep is necessary to ensure normal healthy cognitive functioning, it can also enhance performance beyond the boundaries of the normal condition. This article discusses the enhancing potential of sleep, mainly focusing on the domain of learning and memory. Sleep is known to facilitate the consolidation of memories learned before sleep as well as the acquisition of new memories to be learned after sleep. According to a widely held model this beneficial effect of sleep relies on the neuronal reactivation of memories during sleep that is associated with sleep-specific brain oscillations (slow oscillations, spindles, ripples) as well as a characteristic neurotransmitter milieu. Recent research indicates that memory processing during sleep can be boosted by (i) cueing memory reactivation during sleep; (ii) stimulating sleep-specific brain oscillations; and (iii) targeting specific neurotransmitter systems pharmacologically. Olfactory and auditory cues can be used, for example, to increase reactivation of associated memories during post-learning sleep. Intensifying neocortical slow oscillations (the hallmark of slow wave sleep (SWS)) by electrical or auditory stimulation and modulating specific neurotransmitters such as noradrenaline and glutamate likewise facilitates memory processing during sleep. With this evidence in mind, this article concludes by discussing different methodological caveats and ethical issues that should be considered when thinking about using sleep for cognitive enhancement in everyday applications. PMID:24765066

  6. Superluminal and slow light in {lambda}-type three-level atoms via squeezed vacuum and spontaneously generated coherence

    SciTech Connect

    Carreno, F.; Calderon, Oscar G.; Anton, M.A.

    2005-06-15

    We study the dispersion and absorption spectra of a weak probe in a {lambda}-type three-level atomic system with closely ground sublevels driven by a strong field and damped by a broadband squeezed vacuum. We analyze the interplay between the spontaneous generated coherence and the squeezed field on the susceptibility of the atomic system. We find that by varying the intensity of the squeezed field the group velocity of a weak pulse can change from subluminal to superluminal. In addition we exploit the fact that the properties of the atomic medium can be dramatically modified by controlling the relative phase between the driving field and the squeezed field, allowing us to manipulate the group velocity at which light propagates. The physical origin of this phenomenon corresponds to a transfer of the atomic coherence from electromagnetically induced transparency to electromagnetically induced absorption. Besides, this phenomenon is achieved under nearly transparency conditions and with negligible distortion of the propagation pulse.

  7. Neuropsychological impairment in early-onset hydrocephalus and epilepsy with continuous spike-waves during slow-wave sleep: A case report and literature review

    PubMed Central

    Posar, Annio; Parmeggiani, Antonia

    2013-01-01

    Epilepsy with continuous spike-waves during slow-wave sleep (CSWS) is often characterized by a severe cognitive and behavioral impairment. Symptomatic cases also include patients with an early-onset hydrocephalus, but in literature detailed neuropsychological data on these subjects are not available. We describe the results of serial cognitive assessments in a girl with shunted early-onset hydrocephalus, followed by partial epilepsy complicated with CSWS at 4 years 10 months, in which a dramatic cognitive and behavioral deterioration occurred few months after CSWS onset. Adrenocorticotropic hormone treatment improved both clinical and electroencephalogram picture, but an impairment of visual perception, visual-motor coordination and executive functions persisted after CSWS disappearance. We hypothesize, in this case, an involvement of right occipital-parietal lobe and prefrontal lobe. PMID:24082936

  8. EEG Bands of Wakeful Rest, Slow-Wave and Rapid-Eye-Movement Sleep at Different Brain Areas in Rats.

    PubMed

    Jing, Wei; Wang, Yanran; Fang, Guangzhan; Chen, Mingming; Xue, Miaomiao; Guo, Daqing; Yao, Dezhong; Xia, Yang

    2016-01-01

    Accumulating evidence reveals that neuronal oscillations with various frequency bands in the brain have different physiological functions. However, the frequency band divisions in rats were typically based on empirical spectral distribution from limited channels information. In the present study, functionally relevant frequency bands across vigilance states and brain regions were identified using factor analysis based on 9 channels EEG signals recorded from multiple brain areas in rats. We found that frequency band divisions varied both across vigilance states and brain regions. In particular, theta oscillations during REM sleep were subdivided into two bands, 5-7 and 8-11 Hz corresponding to the tonic and phasic stages, respectively. The spindle activities of SWS were different along the anterior-posterior axis, lower oscillations (~16 Hz) in frontal regions and higher in parietal (~21 Hz). The delta and theta activities co-varied in the visual and auditory cortex during wakeful rest. In addition, power spectra of beta oscillations were significantly decreased in association cortex during REM sleep compared with wakeful rest. These results provide us some new insights into understand the brain oscillations across vigilance states, and also indicate that the spatial factor should not be ignored when considering the frequency band divisions in rats. PMID:27536231

  9. EEG Bands of Wakeful Rest, Slow-Wave and Rapid-Eye-Movement Sleep at Different Brain Areas in Rats

    PubMed Central

    Jing, Wei; Wang, Yanran; Fang, Guangzhan; Chen, Mingming; Xue, Miaomiao; Guo, Daqing; Yao, Dezhong; Xia, Yang

    2016-01-01

    Accumulating evidence reveals that neuronal oscillations with various frequency bands in the brain have different physiological functions. However, the frequency band divisions in rats were typically based on empirical spectral distribution from limited channels information. In the present study, functionally relevant frequency bands across vigilance states and brain regions were identified using factor analysis based on 9 channels EEG signals recorded from multiple brain areas in rats. We found that frequency band divisions varied both across vigilance states and brain regions. In particular, theta oscillations during REM sleep were subdivided into two bands, 5–7 and 8–11 Hz corresponding to the tonic and phasic stages, respectively. The spindle activities of SWS were different along the anterior-posterior axis, lower oscillations (~16 Hz) in frontal regions and higher in parietal (~21 Hz). The delta and theta activities co-varied in the visual and auditory cortex during wakeful rest. In addition, power spectra of beta oscillations were significantly decreased in association cortex during REM sleep compared with wakeful rest. These results provide us some new insights into understand the brain oscillations across vigilance states, and also indicate that the spatial factor should not be ignored when considering the frequency band divisions in rats. PMID:27536231

  10. [Updated relationship between sleep and erectile function].

    PubMed

    Zhang, Fan-bo; Jiang, Rui

    2016-03-01

    Penile erection (PE) is a physiological phenomenon involving complex mechanisms. PE may occur as reactive erections, psychogenic erections in the conscious state and spontaneous erections during the sleep. Sleep-related PE refers to the erections occurring spontaneously during the sleep with rapid eye movement. Studies have shown a correlation between sleep and PE as well as between sleep disorders and erectile dysfunction but not yet revealed the exact mechanisms. This paper updates the relationship between sleep and erectile function. PMID:27172667

  11. Ostriches Sleep like Platypuses

    PubMed Central

    Lesku, John A.; Meyer, Leith C. R.; Fuller, Andrea; Maloney, Shane K.; Dell'Omo, Giacomo

    2011-01-01

    Mammals and birds engage in two distinct states of sleep, slow wave sleep (SWS) and rapid eye movement (REM) sleep. SWS is characterized by slow, high amplitude brain waves, while REM sleep is characterized by fast, low amplitude waves, known as activation, occurring with rapid eye movements and reduced muscle tone. However, monotremes (platypuses and echidnas), the most basal (or ‘ancient’) group of living mammals, show only a single sleep state that combines elements of SWS and REM sleep, suggesting that these states became temporally segregated in the common ancestor to marsupial and eutherian mammals. Whether sleep in basal birds resembles that of monotremes or other mammals and birds is unknown. Here, we provide the first description of brain activity during sleep in ostriches (Struthio camelus), a member of the most basal group of living birds. We found that the brain activity of sleeping ostriches is unique. Episodes of REM sleep were delineated by rapid eye movements, reduced muscle tone, and head movements, similar to those observed in other birds and mammals engaged in REM sleep; however, during REM sleep in ostriches, forebrain activity would flip between REM sleep-like activation and SWS-like slow waves, the latter reminiscent of sleep in the platypus. Moreover, the amount of REM sleep in ostriches is greater than in any other bird, just as in platypuses, which have more REM sleep than other mammals. These findings reveal a recurring sequence of steps in the evolution of sleep in which SWS and REM sleep arose from a single heterogeneous state that became temporally segregated into two distinct states. This common trajectory suggests that forebrain activation during REM sleep is an evolutionarily new feature, presumably involved in performing new sleep functions not found in more basal animals. PMID:21887239

  12. Axo-glial dysjunction. A novel structural lesion that accounts for poorly reversible slowing of nerve conduction in the spontaneously diabetic bio-breeding rat.

    PubMed Central

    Sima, A A; Lattimer, S A; Yagihashi, S; Greene, D A

    1986-01-01

    Biochemical abnormalities in peripheral nerve are thought to precede and condition the development of diabetic neuropathy, but metabolic intervention in chronic diabetic neuropathy produces only limited acute clinical response. The residual, metabolically unresponsive neurological deficits have never been rigorously defined in terms of either persistent metabolic derangements or irreversible structural defects because human nerve tissue is rarely accessible for anatomical and biochemical study and experimentally diabetic animals do not develop the structural hallmarks of human diabetic neuropathy. Detailed neuroanatomical-functional-biochemical correlation was therefore undertaken in long-term spontaneously diabetic BB-Wistar rats that functionally and structurally model human diabetic neuropathy. Vigorous insulin replacement in chronically diabetic BB rats essentially normalized both the sural nerve fiber caliber spectrum and the decreased sciatic nerve myo-inositol and (Na,K)-ATPase levels generally associated with conduction slowing in diabetic animals; yet, nerve conduction was only partially restored toward normal. Morphometric analysis revealed a striking disappearance of paranodal axo-glial junctional complexes that was not corrected by insulin replacement. Loss of these strategic junctional complexes, which are thought to limit lateral migration of axolemmal Na channels away from nodes of Ranvier, correlates with and can account for the diminished nodal Na permeability and resultant nodal conduction delay characteristic of chronic diabetic neuropathy in this animal model. Images PMID:3003160

  13. Brain and muscle oxygenation monitoring using near-infrared spectroscopy (NIRS) during all-night sleep

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongxing; Khatami, Ramin

    2013-03-01

    The hemodynamic changes during natural human sleep are still not well understood. NIRS is ideally suited for monitoring the hemodynamic changes during sleep due to the properties of local measurement, totally safe application and good tolerance to motion. Several studies have been conducted using NIRS in both normal subjects and patients with various sleep disorders during sleep to characterize the hemodynamic changing patterns during different sleep stages and during different symptoms such as obstructive apneas. Here we assessed brain and muscle oxygenation changes in 7 healthy adults during all-night sleep with combined polysomnography measurement to test the notion if hemodynamic changes in sleep are indeed brain specific. We found that muscle and brain showed similar hemodynamic changes during sleep initiation. A decrease in HbO2 and tissue oxygenation index (TOI) while an increase in HHb was observed immediately after sleep onset, and an opposite trend was found after transition with progression to deeper slow-wave sleep (SWS) stage. Spontaneous low frequency oscillations (LFO) and very low frequency oscillations (VLFO) were smaller (Levene's test, p<0.05) during SWS compared to light sleep (LS) and rapid-eye-movement (REM) sleep in both brain and muscle. Spectral analysis of the NIRS signals measured from brain and muscle also showed reductions in VLFO and LFO powers during SWS with respect to LS and REM sleep. These results indicate a systemic attenuation rather than local cerebral reduction of spontaneous hemodynamic activity in SWS. A systemic physiological mechanism may exist to regulate the hemodynamic changes in brain and muscle during sleep.

  14. A Model of Spontaneous Complex Tremor Migration Patterns and Background Slow-Slip Events via Interaction of Brittle Asperities and a Ductile Matrix

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Ampuero, J. P.

    2014-12-01

    Slow-slip events (SSE) and tectonic tremors offer a unique window into a broad spectrum of earthquake behavior and fault mechanics at the bottom of seismogenic zones. Our previous heterogeneous fault models composed of brittle asperities embedded in a matrix with velocity weakening-to-strengthening transition reproduced tremor migration patterns observed in the Cascadia subduction zone including forward tremor propagation and Rapid Tremor Reversals (RTRs). Tremors were driven by a background SSE whose existence did not require tremors. Here we assess the importance of feedback between tremors and SSE by considering a ductile (pure velocity-strengthening) background matrix. In this new model complex tremor swarms and SSE result solely from the interaction between brittle asperity failures via intervening transient creep. In particular, in the absence of tremor asperities the model produces no SSE. The new model is less complicated than our previous one and matches some observations better. It reproduces the scale and recurrence interval of large tremor episodes and the migration speed and distance of RTR observed in Cascadia, and the ratio of RTR to forward migration speeds spans a wider range. Observations of tremor-genic and tremor-less slow slip occurring in a same segment of the Cascadia subduction zone suggest that natural faults are in between these two end-member models. We study the tremor-driven SSE model through numerical simulations of heterogeneous rate-and-state faults with mixed velocity-weakening (VW) and velocity-strengthening (VS) materials. We find that the (b-a)*sigma value (effectively the frictional properties and pore pressure) of the VW fault portions determine the criticalness of the whole fault (i.e. its ability to produce spontaneous transient events). A combined analytical and numerical study of fault criticalness as a function of density of VW material and contrast of (b-a)*sigma values reveals subcritical-to-supercritical transitions

  15. Altered intrinsic regional brain spontaneous activity and subjective sleep quality in patients with chronic primary insomnia: a resting-state fMRI study

    PubMed Central

    Dai, Xi-Jian; Peng, De-Chang; Gong, Hong-Han; Wan, Ai-Lan; Nie, Xiao; Li, Hai-Jun; Wang, Yi-Xiang J

    2014-01-01

    Study objective To prospectively explore the underlying regional homogeneity (ReHo) brain-activity deficit in patients with chronic primary insomnia (PCPIs) and its relationship with clinical features. Design The ReHo method and Statistical Parametric Mapping 8 software were used to evaluate whether resting-state localized brain activity was modulated between PCPIs and good sleepers (GSs), and correlation analysis between altered regional brain areas and clinical features was calculated. Patients and participants Twenty-four PCPIs (17 females, seven males) and 24 (12 females, 12 males) age-, sex-, and education-matched GSs. Measurements and results PCPIs disturbed subjective sleep quality, split positive mood, and exacerbated negative moods. Compared with GSs, PCPIs showed higher ReHo in left fusiform gyrus, and lower ReHo in bilateral cingulate gyrus and right cerebellum anterior lobe. Compared with female GSs, female PCPIs showed higher ReHo in the left fusiform gyrus and right posterior cingulate, and lower ReHo in the left cerebellum anterior lobe and left superior frontal gyrus. Compared with male GSs, male PCPIs showed higher ReHo in the right temporal lobe and lower ReHo in the bilateral frontal lobe. The fusiform gyrus showed strong positive correlations and the frontal lobe showed negative correlations with the clinical measurements. Conclusion The ReHo analysis is a useful noninvasive imaging tool for the detection of cerebral changes and the indexing of clinical features. The abnormal spontaneous activity areas provided important information on the neural mechanisms underlying emotion and sleep-quality impairment in PCPIs. PMID:25484585

  16. No phylogeny without ontogeny: a comparative and developmental search for the sources of sleep-like neural and behavioral rhythms.

    PubMed

    Corner, Michael; van der Togt, Chris

    2012-02-01

    A comprehensive review is presented of reported aspects and putative mechanisms of sleep-like motility rhythms throughout the animal kingdom. It is proposed that 'rapid eye movement (REM) sleep' be regarded as a special case of a distinct but much broader category of behavior, 'rapid body movement (RBM) sleep', defined by intrinsically-generated and apparently non-purposive movements. Such a classification completes a 2 × 2 matrix defined by the axes sleep versus waking and active versus quiet. Although 'paradoxical' arousal of forebrain electrical activity is restricted to warm-blooded vertebrates, we urge that juvenile or even infantile stages of development be investigated in cold-blooded animals, in view of the many reports of REM-like spontaneous motility (RBMs) in a wide range of species during sleep. The neurophysiological bases for motorically active sleep at the brainstem level and for slow-wave sleep in the forebrain appear to be remarkably similar, and to be subserved in both cases by a primitive diffuse mode of neuronal organization. Thus, the spontaneous synchronous burst discharges which are characteristics of the sleeping brain can be readily simulated even by highly unstructured neural network models. Neuromotor discharges during active sleep appear to reflect a hierarchy of simple relaxation oscillation mechanisms, spanning a wide range of spike-dependent relaxation times, whereas the periodic alternation of active and quiet sleep states more likely results from the entrainment of intrinsic cellular rhythms and/or from activity-dependent homeostatic changes in network excitability. PMID:22233887

  17. Common Sleep Problems (For Teens)

    MedlinePlus

    ... stages 1, 2, 3, 4, and REM (rapid eye movement) sleep make up a sleep cycle . One complete ... person can wake up easily. During these stages, eye movements slow down and eventually stop, heart and breathing ...

  18. Oscillating square wave Transcranial Direct Current Stimulation (tDCS) delivered during slow wave sleep does not improve declarative memory more than sham: A randomized sham controlled crossover study

    PubMed Central

    Sahlem, Gregory L.; Badran, Bashar W.; Halford, Jonathan J.; Williams, Nolan R.; Korte, Jeffrey E.; Leslie, Kimberly; Strachan, Martha; Breedlove, Jesse L.; Runion, Jennifer; Bachman, David L.; Uhde, Thomas W.; Borckardt, Jeffery J.; George, Mark S.

    2015-01-01

    Background A 2006 trial in healthy medical students found that anodal slow oscillating tDCS delivered bi-frontally during slow wave sleep had an enhancing effect in declarative, but not procedural memory. Although there have been supporting animal studies, and similar findings in pathological groups, this study has not been replicated, or refuted, in the intervening years. We therefore tested these earlier results for replication using similar methods with the exception of current wave form (square in our study, nearly sinusoidal in the original). Objective/Hypothesis Our objective was to test the findings of a 2006 trial suggesting bi-frontal anodal tDCS during slow wave sleep enhances declarative memory. Methods Twelve students (mean age 25, 9 women) free of medical problems underwent two testing conditions (active, sham) in a randomized counterbalanced fashion. Active stimulation consisted of oscillating square wave tDCS delivered during early Non-Rapid Eye Movement (NREM) sleep. The sham condition consisted of setting-up the tDCS device and electrodes, but not turning it on during sleep. tDCS was delivered bi-frontally with anodes placed at F3/F4, and cathodes placed at mastoids. Current density was 0.517mA/CM2, and oscillated between zero and maximal current at a frequency of 0.75Hz. Stimulation occurred during five-five minute blocks with one-minute inter-block intervals (25 minutes total stimulation). The primary outcomes were both declarative memory consolidation measured by a paired word association test (PWA), and non-declarative memory, measured by a non-dominant finger-tapping test (FTT). We also recorded and analyzed sleep EEG. Results There was no difference in the number of paired word associations remembered before compared to after sleep [(active = 3.1±3.0SD more associations) (sham = 3.8±3.1S.D more associations)]. Finger tapping improved, (non-significantly) following active stimulation [(3.6±2.7 S.D. correctly typed sequences) compared to

  19. Efficacy of paced breathing for insomnia: enhances vagal activity and improves sleep quality.

    PubMed

    Tsai, H J; Kuo, Terry B J; Lee, Guo-She; Yang, Cheryl C H

    2015-03-01

    Fourteen self-reported insomniacs (SRI) and 14 good sleepers (GS) had their cardiac neuronal activity assessed by heart rate variability (HRV) under controlled respiration at a slow frequency rate of 0.1 Hz, and a forced rate of 0.2 Hz during daytime rest. Nighttime sleep was measured by polysomnography. The SRI showed depressed high frequency power of HRV compared to the GS. An increased total power of HRV was observed among the SRI during slow, paced breathing compared with spontaneous breathing and 0.2 Hz. Sleep onset latency, number of awakenings, and awakening time during sleep were decreased and sleep efficiency was increased if SRI practiced slow, paced breathing exercises for 20 min before going to sleep. Our results indicate that there is autonomic dysfunction among insomniacs, especially in relation to vagal activity; however, this decreased vagal activity can be facilitated by practicing slow, paced breathing, thereby improving sleep quality. PMID:25234581

  20. Sleep in an Amazonian manatee, Trichechus inunguis.

    PubMed

    Mukhametov, L M; Lyamin, O I; Chetyrbok, I S; Vassilyev, A A; Diaz, R P

    1992-04-15

    For the first time, sleep was studied in a representative of the order of Sirenia. Slow wave sleep occupied 27%, and paradoxical sleep 1% of the total recording time in the Amazonian manatee. Trichechus inunguis. The circadian rhythmicity of sleep was pronounced. During the sleep period, the manatee woke up for a short time for each respiratory act. Interhemispheric asynchrony of the electrocortical slow wave activity was found. PMID:1582500

  1. Sleep in pregnancy.

    PubMed

    Richardson, P

    1996-07-01

    The article examines relationships between pregnancy and maternal sleep. Specifically, sleep as a restorative process is considered with regard for the metabolic and arousal demands of childbearing. The analysis draws attention to the limited number of studies in the area and the need for greater research interest in pregnancy sleep phenomena. The available evidence indicates that maternal slow-wave and rapid eye movement which are key to anabolic activity and neural-cerebral recharge, are protected throughout pregnancy until perhaps the last 3 to 4 weeks before delivery. The sleep disturbances about which term gravidas complain appear to be based on increased periods of wakefulness after sleep onset. PMID:8717994

  2. Sleep spindles and hippocampal functional connectivity in human NREM sleep.

    PubMed

    Andrade, Kátia C; Spoormaker, Victor I; Dresler, Martin; Wehrle, Renate; Holsboer, Florian; Sämann, Philipp G; Czisch, Michael

    2011-07-13

    We investigated human hippocampal functional connectivity in wakefulness and throughout non-rapid eye movement sleep. Young healthy subjects underwent simultaneous EEG and functional magnetic resonance imaging (fMRI) measurements at 1.5 T under resting conditions in the descent to deep sleep. Continuous 5 min epochs representing a unique sleep stage (i.e., wakefulness, sleep stages 1 and 2, or slow-wave sleep) were extracted. fMRI time series of subregions of the hippocampal formation (HF) (cornu ammonis, dentate gyrus, and subiculum) were extracted based on cytoarchitectonical probability maps. We observed sleep stage-dependent changes in HF functional coupling. The HF was integrated to variable strength in the default mode network (DMN) in wakefulness and light sleep stages but not in slow-wave sleep. The strongest functional connectivity between the HF and neocortex was observed in sleep stage 2 (compared with both slow-wave sleep and wakefulness). We observed a strong interaction of sleep spindle occurrence and HF functional connectivity in sleep stage 2, with increased HF/neocortical connectivity during spindles. Moreover, the cornu ammonis exhibited strongest functional connectivity with the DMN during wakefulness, while the subiculum dominated hippocampal functional connectivity to frontal brain regions during sleep stage 2. Increased connectivity between HF and neocortical regions in sleep stage 2 suggests an increased capacity for possible global information transfer, while connectivity in slow-wave sleep is reflecting a functional system optimal for segregated information reprocessing. Our data may be relevant to differentiating sleep stage-specific contributions to neural plasticity as proposed in sleep-dependent memory consolidation. PMID:21753010

  3. Characterization of Topographically Specific Sleep Spindles in Mice

    PubMed Central

    Kim, Dongwook; Hwang, Eunjin; Lee, Mina; Sung, Hokun; Choi, Jee Hyun

    2015-01-01

    Study Objective: Sleep spindles in humans have been classified as slow anterior and fast posterior spindles; recent findings indicate that their profiles differ according to pharmacology, pathology, and function. However, little is known about the generation mechanisms within the thalamocortical system for different types of spindles. In this study, we aim to investigate the electrophysiological behaviors of the topographically distinctive spindles within the thalamocortical system by applying high-density EEG and simultaneous thalamic LFP recordings in mice. Design: 32-channel extracranial EEG and 2-channel thalamic LFP were recorded simultaneously in freely behaving mice to acquire spindles during spontaneous sleep. Subjects: Hybrid F1 male mice of C57BL/6J and 129S4/svJae. Measurements and Results: Spindle events in each channel were detected by spindle detection algorithm, and then a cluster analysis was applied to classify the topographically distinctive spindles. All sleep spindles were successfully classified into 3 groups: anterior, posterior, and global spindles. Each spindle type showed distinct thalamocortical activity patterns regarding the extent of similarity, phase synchrony, and time lags between cortical and thalamic areas during spindle oscillation. We also found that sleep slow waves were likely to associate with all types of sleep spindles, but also that the ongoing cortical decruitment/recruitment dynamics before the onset of spindles and their relationship with spindle generation were also variable, depending on the spindle types. Conclusion: Topographically specific sleep spindles show distinctive thalamocortical network behaviors. Citation: Kim D, Hwang E, Lee M, Sung H, Choi JH. Characterization of topographically specific sleep spindles in mice. SLEEP 2015;38(1):85–96. PMID:25325451

  4. Slow Echo: Facial EMG Evidence for the Delay of Spontaneous, but Not Voluntary, Emotional Mimicry in Children with Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Oberman, Lindsay M.; Winkielman, Piotr; Ramachandran, Vilayanur S.

    2009-01-01

    Spontaneous mimicry, including that of emotional facial expressions, is important for socio-emotional skills such as empathy and communication. Those skills are often impacted in autism spectrum disorders (ASD). Successful mimicry requires not only the activation of the response, but also its appropriate speed. Yet, previous studies examined ASD…

  5. Metabolic consequences of sleep and sleep loss

    PubMed Central

    Van Cauter, Eve; Spiegel, Karine; Tasali, Esra; Leproult, Rachel

    2015-01-01

    Reduced sleep duration and quality appear to be endemic in modern society. Curtailment of the bedtime period to minimum tolerability is thought to be efficient and harmless by many. It has been known for several decades that sleep is a major modulator of hormonal release, glucose regulation and cardiovascular function. In particular, slow wave sleep (SWS), thought to be the most restorative sleep stage, is associated with decreased heart rate, blood pressure, sympathetic nervous activity and cerebral glucose utilization, compared with wakefulness. During SWS, the anabolic growth hormone is released while the stress hormone cortisol is inhibited. In recent years, laboratory and epidemiologic evidence have converged to indicate that sleep loss may be a novel risk factor for obesity and type 2 diabetes. The increased risk of obesity is possibly linked to the effect of sleep loss on hormones that play a major role in the central control of appetite and energy expenditure, such as leptin and ghrelin. Reduced leptin and increased ghrelin levels correlate with increases in subjective hunger when individuals are sleep restricted rather than well rested. Given the evidence, sleep curtailment appears to be an important, yet modifiable, risk factor for the metabolic syndrome, diabetes and obesity. The marked decrease in average sleep duration in the last 50 years coinciding with the increased prevalence of obesity, together with the observed adverse effects of recurrent partial sleep deprivation on metabolism and hormonal processes, may have important implications for public health. PMID:18929315

  6. Chronic hiccups and sleep.

    PubMed

    Arnulf, I; Boisteanu, D; Whitelaw, W A; Cabane, J; Garma, L; Derenne, J P

    1996-04-01

    To explore the effect of sleep on hiccups, we studied eight patients aged 20-81 years, all males with chronic hiccups lasting 7 days to 7 years, by means of overnight polysomnography. The incidence of new bouts of hiccups and the likelihood of hiccups being present were both highest in wakefulness and became progressively lower through stages I-IV of slow wave sleep (SWS) to rapid eye movement sleep (REMS). There was a significant tendency for hiccups to disappear at sleep onset and REMS onset. Of all 21 bouts of hiccups that were observed to stop, 10/21 did so during an apnea or hypopnea. Frequency of hiccups within a bout slowed progressively from wakefulness through the stages of SWS to REMS. For the whole group, mean frequency decreased significantly from wakefulness [(25.6 +/- 12.1), (mean +/- SD)] to sleep onset or stage I (22.3 +/- 12.2). Sleep latency was increased from 8 +/- 16.3 minutes when hiccups were absent to 16.35 +/- 19.9 minutes when it was present. Sleep efficiency was poor because of long waking periods, and there were deficiencies of both SWS and REMS. Hiccups themselves were not responsible for any arousals or awakenings. We conclude that neural mechanisms responsible for hiccups are strongly influenced by sleep state and that hiccups disrupt sleep onset but not established sleep. PMID:8723381

  7. Long-term total sleep deprivation decreases the default spontaneous activity and connectivity pattern in healthy male subjects: a resting-state fMRI study

    PubMed Central

    Dai, Xi-Jian; Liu, Chun-Lei; Zhou, Ren-Lai; Gong, Hong-Han; Wu, Bin; Gao, Lei; Wang, Yi-Xiang J

    2015-01-01

    Objective The aim of this study is to use resting-state functional connectivity (rsFC) and amplitude of low-frequency fluctuation (ALFF) methods to explore intrinsic default-mode network (DMN) impairment after sleep deprivation (SD) and its relationships with clinical features. Methods Twelve healthy male subjects underwent resting-state functional magnetic resonance imaging twice: once following rested wakefulness (RW) and the other following 72 hours of total SD. Before the scans, all subjects underwent the attention network test (ANT). The independent component analysis (ICA), rsFC, and ALFF methods were used to examine intrinsic DMN impairment. Receiver operating characteristic (ROC) curve was used to distinguish SD status from RW status. Results Compared with RW subjects, SD subjects showed a lower accuracy rate (RW =96.83%, SD =77.67%; P<0.001), a slower reaction time (RW =695.92 ms; SD =799.18 ms; P=0.003), a higher lapse rate (RW =0.69%, SD =19.29%; P<0.001), and a higher intraindividual coefficient of variability in reaction time (RW =0.26, SD =0.33; P=0.021). The ICA method showed that, compared with RW subjects, SD subjects had decreased rsFC in the right inferior parietal lobule (IPL, BA40) and in the left precuneus (PrC)/posterior cingulate cortex (PCC) (BA30, 31). The two different areas were selected as regions of interest (ROIs) for future rsFC analysis. Compared with the same in RW subjects, in SD subjects, the right IPL showed decreased rsFC with the left PrC (BA7) and increased rsFC with the left fusiform gyrus (BA37) and the left cluster of middle temporal gyrus and inferior temporal gyrus (BA37). However, the left PrC/PCC did not show any connectivity differences. Compared with RW subjects, SD subjects showed lower ALFF area in the left IPL (BA39, 40). The left IPL, as an ROI, showed decreased rsFC with the right cluster of IPL and superior temporal gyrus (BA39, 40). ROC curve analysis showed that the area under the curve (AUC) value of the

  8. Effect of Daytime Exercise on Sleep Eeg and Subjective Sleep

    NASA Astrophysics Data System (ADS)

    Sasazawa, Y.; Kawada, T.; Kiryu, Y.

    1997-08-01

    This study was designed to assess the effects of daytime physical exercise on the quality of objective and subjective sleep by examining all-night sleep EEGs. The subjects were five male students, aged 19 to 20 years, who were in the habit of performing regular daytime exercise. The sleep polygraphic parameters in this study were sleep stage time as a percentage of total sleep time (%S1, %S2, %S(3+4), %SREM, %MT), time in bed (TIB), sleep time (ST), total sleep time (TST), sleep onset latency (SOL), waking from sleep, sleep efficiency, number of awakenings, number of stage shifts, number of spindles, and percentages of α and δ waves, all of which were determined by an automatic computer analysis system. The OSA questionnaire was used to investigate subjective sleep. The five scales of the OSA used were sleepiness, sleep maintenance, worry, integrated sleep feeling, and sleep initiation. Each sleep parameter was compared in the exercise and the non-exercise groups. Two-way analysis of variance was applied using subject factor and exercise factor. The main effect of the subject was significant in all parameters and the main effect of exercise in %S(3+4), SOL and sleep efficiency, among the objective sleep parameters. The main effects of the subject, except sleepiness, were significant, as was the main effect of exercise on sleep initiation, among the subjective sleep parameters. These findings suggest that daytime exercise shortened sleep latency and prolonged slow-wave sleep, and that the subjects fell asleep more easily on exercise days. There were also significant individual differences in both the objective and subjective sleep parameters.

  9. Large-scale functional brain networks in human non-rapid eye movement sleep: insights from combined electroencephalographic/functional magnetic resonance imaging studies.

    PubMed

    Spoormaker, Victor I; Czisch, Michael; Maquet, Pierre; Jäncke, Lutz

    2011-10-13

    This paper reviews the existing body of knowledge on the neural correlates of spontaneous oscillations, functional connectivity and brain plasticity in human non-rapid eye movement (NREM) sleep. The first section reviews the evidence that specific sleep events as slow waves and spindles are associated with transient increases in regional brain activity. The second section describes the changes in functional connectivity during NREM sleep, with a particular focus on changes within a low-frequency, large-scale functional brain network. The third section will discuss the possibility that spontaneous oscillations and differential functional connectivity are related to brain plasticity and systems consolidation, with a particular focus on motor skill acquisition. Implications for the mode of information processing per sleep stage and future experimental studies are discussed. PMID:21893524

  10. Sleep-waking discharge profiles of dorsal raphe nucleus neurons in mice.

    PubMed

    Sakai, K

    2011-12-01

    We have recorded, for the first time, in non-anesthetized, head-restrained mice, a total of 407 single units throughout the dorsal raphe nucleus (DR), which contains serotonin (5-hydroxytryptamine, 5-HT) neurons, during the complete wake-sleep cycle. The mouse DR was found to contain a large proportion (52.0%) of waking (W)-active neurons, together with many sleep-active (24.8%) and W/paradoxical sleep (PS)-active (18.4%) neurons and a few state-unrelated neurons (4.7%). The W-active, W/PS-active, and sleep-active neurons displayed a biphasic narrow or triphasic broad action potential. Of the 212 W-active neurons, 194 were judged serotonergic (5-HT W-active neurons) because of their triphasic long-duration action potential and low rate of spontaneous discharge, while the remaining 18 were judged non-serotonergic (non-5-HT W-active neurons) because of their biphasic narrow action potential and higher rate of spontaneous discharge. The 5-HT W-active neurons were subdivided into four groups, types I, II, III, and IV, on the basis of differences in firing pattern during wake-sleep states, their waking selectivity of discharge being in the order type I>type II>type III>type IV. During the transition from sleep to waking, the vast majority of waking-specific or waking-selective type I and II neurons discharged after onset of waking, as seen with non-5-HT W-specific neurons. Triphasic DR W/PS-active neurons were characterized by a low rate of spontaneous discharge and a similar distribution to that of tyrosine hydroxylase-immunoreactive, dopaminergic neurons. Triphasic DR slow-wave sleep (SWS)-active and SWS/PS neurons were also characterized by slow firing. At the transition from sleep to waking, sleep-selective neurons with no discharge activity during waking ceased firing before onset of waking, while, at the transition from waking to sleep, they fired after onset of sleep. The present study shows a marked heterogeneity and functional topographic organization of both

  11. Increased Alpha (8-12 Hz) Activity during Slow Wave Sleep as a Marker for the Transition from Implicit Knowledge to Explicit Insight

    ERIC Educational Resources Information Center

    Yordanova, Juliana; Kolev, Vasil; Wagner, Ullrich; Born, Jan; Verleger, Rolf

    2012-01-01

    The number reduction task (NRT) allows us to study the transition from implicit knowledge of hidden task regularities to explicit insight into these regularities. To identify sleep-associated neurophysiological indicators of this restructuring of knowledge representations, we measured frequency-specific power of EEG while participants slept during…

  12. Optimizing sleep/wake schedules in space: Sleep during chronic nocturnal sleep restriction with and without diurnal naps

    NASA Astrophysics Data System (ADS)

    Mollicone, Daniel J.; Van Dongen, Hans P. A.; Dinges, David F.

    2007-02-01

    Effective sleep/wake schedules for space operations must balance severe time constraints with allocating sufficient time for sleep in order to sustain high levels of neurobehavioral performance. Developing such schedules requires knowledge about the relationship between scheduled "time in bed" (TIB) and actual physiological sleep obtained. A ground-based laboratory study in N=93 healthy adult subjects was conducted to investigate physiological sleep obtained in a range of restricted sleep schedules. Eighteen different conditions with restricted nocturnal anchor sleep, with and without diurnal naps, were examined in a response surface mapping paradigm. Sleep efficiency was found to be a function of total TIB per 24 h regardless of how the sleep was divided among nocturnal anchor sleep and diurnal nap sleep periods. The amounts of sleep stages 1+2 and REM showed more complex relationships with the durations of the anchor and nap sleep periods, while slow-wave sleep was essentially preserved among the different conditions of the experiment. The results of the study indicated that when sleep was chronically restricted, sleep duration was largely unaffected by whether the sleep was placed nocturnally or split between nocturnal anchor sleep periods and daytime naps. Having thus assessed that split-sleep schedules are feasible in terms of obtaining physiological sleep, further research will reveal whether these schedules and the associated variations in the distribution of sleep stages may be advantageous in mitigating neurobehavioral performance impairment in the face of limited time for sleep.

  13. [Sleep in depression].

    PubMed

    Pringuey, D; Darcourt, G

    1990-11-28

    Insomnia is a cardinal symptom of depression, side by side with alterations of mood and slowing down of psychomotor activities. It bears witness to a rupture in the built-in circadian rhythm: architectural changes in sleep betray a biological desynchronization. Insomnia is also a failed attempt at finding a solution to depression. Total deprivation of sleep for one night may damp down the depressive disorders, and so does partial sleep deprivation in the second part of the night during several days. This leads to the conclusion that the waking-sleep system participates in the expression of symptoms of depression or even contributes to the genesis of the disease. PMID:2148377

  14. Reverberation, Storage, and Postsynaptic Propagation of Memories during Sleep

    ERIC Educational Resources Information Center

    Ribeiro, Sidarta; Nicolelis, Miguel A. L.

    2004-01-01

    In mammals and birds, long episodes of nondreaming sleep ("slow-wave" sleep, SW) are followed by short episodes of dreaming sleep ("rapid-eye-movement" sleep, REM). Both SW and REM sleep have been shown to be important for the consolidation of newly acquired memories, but the underlying mechanisms remain elusive. Here we review…

  15. Sustained Sleep Fragmentation Induces Sleep Homeostasis in Mice

    PubMed Central

    Baud, Maxime O.; Magistretti, Pierre J.; Petit, Jean-Marie

    2015-01-01

    Study Objectives: Sleep fragmentation (SF) is an integral feature of sleep apnea and other prevalent sleep disorders. Although the effect of repetitive arousals on cognitive performance is well documented, the effects of long-term SF on electroencephalography (EEG) and molecular markers of sleep homeostasis remain poorly investigated. To address this question, we developed a mouse model of chronic SF and characterized its effect on EEG spectral frequencies and the expression of genes previously linked to sleep homeostasis including clock genes, heat shock proteins, and plasticity-related genes. Design: N/A. Setting: Animal sleep research laboratory. Participants : Sixty-six C57BL6/J adult mice. Interventions: Instrumental sleep disruption at a rate of 60/h during 14 days Measurements and Results: Locomotor activity and EEG were recorded during 14 days of SF followed by recovery for 2 days. Despite a dramatic number of arousals and decreased sleep bout duration, SF minimally reduced total quantity of sleep and did not significantly alter its circadian distribution. Spectral analysis during SF revealed a homeostatic drive for slow wave activity (SWA; 1–4 Hz) and other frequencies as well (4–40 Hz). Recordings during recovery revealed slow wave sleep consolidation and a transient rebound in SWA, and paradoxical sleep duration. The expression of selected genes was not induced following chronic SF. Conclusions: Chronic sleep fragmentation (SF) increased sleep pressure confirming that altered quality with preserved quantity triggers core sleep homeostasis mechanisms. However, it did not induce the expression of genes induced by sleep loss, suggesting that these molecular pathways are not sustainably activated in chronic diseases involving SF. Citation: Baud MO, Magistretti PJ, Petit JM. Sustained sleep fragmentation induces sleep homeostasis in mice. SLEEP 2015;38(4):567–579. PMID:25325477

  16. Spontaneous Slow Fluctuation of EEG Alpha Rhythm Reflects Activity in Deep-Brain Structures: A Simultaneous EEG-fMRI Study

    PubMed Central

    Omata, Kei; Hanakawa, Takashi; Morimoto, Masako; Honda, Manabu

    2013-01-01

    The emergence of the occipital alpha rhythm on brain electroencephalogram (EEG) is associated with brain activity in the cerebral neocortex and deep brain structures. To further understand the mechanisms of alpha rhythm power fluctuation, we performed simultaneous EEGs and functional magnetic resonance imaging recordings in human subjects during a resting state and explored the dynamic relationship between alpha power fluctuation and blood oxygenation level-dependent (BOLD) signals of the brain. Based on the frequency characteristics of the alpha power time series (APTS) during 20-minute EEG recordings, we divided the APTS into two components: fast fluctuation (0.04–0.167 Hz) and slow fluctuation (0–0.04 Hz). Analysis of the correlation between the MRI signal and each component revealed that the slow fluctuation component of alpha power was positively correlated with BOLD signal changes in the brain stem and the medial part of the thalamus and anterior cingulate cortex, while the fast fluctuation component was correlated with the lateral part of the thalamus and the anterior cingulate cortex, but not the brain stem. In summary, these data suggest that different subcortical structures contribute to slow and fast modulations of alpha spectra on brain EEG. PMID:23824708

  17. Sleep during arousal episodes as a function of prior torpor duration in hibernating European ground squirrels.

    PubMed

    Strijkstra, A M; Daan, S

    1997-03-01

    EEG's were recorded in hibernating European ground squirrels during euthermic arousal episodes at an ambient temperature of 5.5 degrees C. Spontaneous torpor bouts ranged from 6 to 15 days, body temperature during torpor was 7.5 degrees C. The torpor duration prior to EEG measurements was experimentally manipulated: the animals were induced to arouse by gentle handling after torpor of less then 1 day (n = 3), 1-2 days (n = 6), 3-4 days (n = 9) and 5-12 days (n = 9). The animals slept 71.5% of euthermic time, of which 61.4% NREM and 10.2% REM sleep. NREM percentage was slightly positively and REM percentage negatively correlated with prior torpor duration (TD). Spectral analysis showed changes in EEG activity during the euthermic phase in the slow wave frequency range (1-4 Hz) and in higher frequencies. Prior TD specifically affected the slow waves. Slow wave activity decreased exponentially during the euthermic phase. The initial slow wave activity showed a systematic increase with prior TD, which could be described by an exponentially saturating function, albeit with a relatively small time constant compared with spontaneous torpor duration. It is concluded that sleep during arousal episodes following torpor at an ambient temperature of 5.5 degrees C is affected both in structure and intensity by prior TD. The results are consistent with the proposition that torpor inhibits the restorative function of sleep. PMID:9125697

  18. Endothelial Function and Sleep: Associations of Flow-Mediated Dilation With Perceived Sleep Quality and Rapid Eye Movement (REM) Sleep

    PubMed Central

    Cooper, Denise C.; Ziegler, Michael G.; Milic, Milos S.; Ancoli-Israel, Sonia; Mills, Paul J.; Loredo, José S.; von Känel, Roland; Dimsdale, Joel E.

    2013-01-01

    Summary Endothelial function typically precedes clinical manifestations of cardiovascular disease and provides a potential mechanism for the associations observed between cardiovascular disease and sleep quality. This study examined how subjective and objective indicators of sleep quality relate to endothelial function, as measured by brachial artery flow-mediated dilation (FMD). In a clinical research center, 100 non-shift working adults (mean age: 36 years) completed FMD testing and the Pittsburgh Sleep Quality Index, along with a polysomnography assessment to obtain the following measures: slow wave sleep, percentage rapid eye movement (REM) sleep, REM sleep latency, total arousal index, total sleep time, wake after sleep onset, sleep efficiency, and apnea hypopnea index. Bivariate correlations and followup multiple regressions examined how FMD related to subjective (i.e., Pittsburgh Sleep Quality Index scores) and objective (i.e., polysomnography-derived) indicators of sleep quality. After FMD showed bivariate correlations with Pittsburgh Sleep Quality Index scores, percentage REM sleep, and REM latency, further examination with separate regression models indicated that these associations remained significant after adjustments for sex, age, race, hypertension, body mass index, apnea hypopnea index, smoking, and income (p's<0.05). Specifically, as FMD decreased, scores on the Pittsburgh Sleep Quality Index increased (indicating decreased subjective sleep quality) and percentage REM sleep decreased, while REM sleep latency increased (p's<0.05). Poorer subjective sleep quality and adverse changes in REM sleep were associated with diminished vasodilation, which could link sleep disturbances to cardiovascular disease. PMID:24033699

  19. Sleep and Women

    MedlinePlus

    ... Benefits Side Effects Variations Tips Healthy Sleep Habits Sleep Disorders by Category Insomnias Insomnia Child Insomnia Short Sleeper ... Work SIDS Sleep apnea Sleep Debt Sleep Deprivation Sleep Disorders Sleep history Sleep hygiene sleep length Sleep Need ...

  20. Time-frequency dynamics during sleep spindles on the EEG in rodents with a genetic predisposition to absence epilepsy (WAG/Rij rats)

    NASA Astrophysics Data System (ADS)

    Hramov, Alexander E.; Sitnikova, Evgenija Y.; Pavlov, Alexey N.; Grubov, Vadim V.; Koronovskii, Alexey A.; Khramova, Marina V.

    2015-03-01

    Sleep spindles are known to appear spontaneously in the thalamocortical neuronal network of the brain during slow-wave sleep; pathological processes in the thalamocortical network may be the reason of the absence epilepsy. The aim of the present work is to study developed changes in the time-frequency structure of sleep spindles during the progressive development of the absence epilepsy in WAG/Rij rats. EEG recordings were made at age 7 and 9 months. Automatic recognition and subsequent analysis of sleep spindles on the EEG were performed using the continuous wavelet transform. The duration of epileptic discharges and the total duration of epileptic activity were found to increase with age, while the duration of sleep spindles, conversely, decreased. In terms of the mean frequency, sleep spindles could be divided into three classes: `slow' (mean frequency 9.3Hz), `medium' (11.4Hz), and `fast' (13.5Hz). Slow and medium (transitional) spindles in five-month-old animals showed increased frequency from the beginning to the end of the spindle. The more intense the epilepsy is, the shorter are the durations of spindles of all types. The mean frequencies of `medium' and `fast' spindles were higher in rats with more intense signs of epilepsy. Overall, high epileptic activity in WAG/Rij rats was linked with significant changes in spindles of the transitional type, with less marked changes in the two traditionally identified types of spindle, slow and fast.

  1. Genotyping Sleep Disorders Patients

    PubMed Central

    Shadan, Farhad F.; Dawson, Arthur; Cronin, John W.; Jamil, Shazia M.; Grizas, Alexandra P.; Koziol, James A.; Kline, Lawrence E.

    2010-01-01

    Objective The genetic susceptibility factors underlying sleep disorders might help us predict prognoses and responses to treatment. Several candidate polymorphisms for sleep disorders have been proposed, but there has as yet inadequate replication or validation that the candidates may be useful in the clinical setting. Methods To assess the validity of several candidate associations, we obtained saliva deoxyribonucleic acid (DNA) samples and clinical information from 360 consenting research participants who were undergoing clinical polysomnograms. Ten single nucleotide polymorphisms (SNPs) were genotyped. These were thought to be related to depression, circadian sleep disorders, sleep apnea, restless legs syndrome (RLS), excessive sleepiness, or to slow waves in sleep. Results With multivariate generalized linear models, the association of TEF rs738499 with depressive symptoms was confirmed. Equivocal statistical evidence of association of rs1801260 (the C3111T SNP in the CLOCK gene) with morningness/eveningness and an association of Apolipoprotein E (APOE) rs429358 with the Epworth Sleepiness Scale (ESS) were obtained, but these associations were not strong enough to be of clinical value by themselves. Predicted association of SNPs with sleep apnea, RLS, and slow wave sleep were not confirmed. Conclusion The SNPs tested would not, by themselves, be of use for clinical genotyping in a sleep clinic. PMID:20396431

  2. Sleep in Children with Williams Syndrome

    PubMed Central

    Mason, Thornton B.A.; Arens, Raanan; Sharman, Jaclyn; Bintliff-Janisak, Brooke; Schultz, Brian; Walters, Arthur S.; Cater, Jacqueline R.; Kaplan, Paige; Pack, Allan I.

    2011-01-01

    Objective To analyze sleep in children with Williams Syndrome (WS) compared to normal healthy controls in order to determine whether particular sleep features are characteristic of WS, and to explore associations between disturbed sleep and behavior. Methods 35 children with genetically-confirmed WS and 35 matched controls underwent overnight polysomnography and performance testing in the Sleep Center at the Children’s Hospital of Philadelphia. Parents completed questionnaires regarding the subjects’ sleep and behavior. Results WS subjects had significantly different sleep than controls, with decreased sleep efficiency, increased respiratory-related arousals, and increased slow wave sleep on overnight polysomnography. WS subjects were also noted to have more difficulty falling asleep, with greater restlessness and more arousals from sleep than controls. 52% of WS subjects had features of attention deficit- hyperactivity disorder. Conclusions Children with WS had significantly different sleep than controls in our sample. These differences demonstrated in our study may reflect genetic influences on sleep. PMID:21940205

  3. Sleep and Breathing at High Altitude.

    PubMed

    Wickramasinghe, Himanshu; Anholm, James D.

    1999-01-01

    Sleep at high altitude is characterized by poor subjective quality, increased awakenings, frequent brief arousals, marked nocturnal hypoxemia, and periodic breathing. A change in sleep architecture with an increase in light sleep and decreasing slow-wave and REM sleep have been demonstrated. Periodic breathing with central apnea is almost universally seen amongst sojourners to high altitude, although it is far less common in long-standing high altitude dwellers. Hypobaric hypoxia in concert with periodic breathing appears to be the principal cause of sleep disruption at altitude. Increased sleep fragmentation accounts for the poor sleep quality and may account for some of the worsened daytime performance at high altitude. Hypoxic sleep disruption contributes to the symptoms of acute mountain sickness. Hypoxemia at high altitude is most severe during sleep. Acetazolamide improves sleep, AMS symptoms, and hypoxemia at high altitude. Low doses of a short acting benzodiazepine (temazepam) may also be useful in improving sleep in high altitude. PMID:11898114

  4. Sleep Disorders

    MedlinePlus

    ... 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 - ...

  5. Sleep Problems

    MedlinePlus

    ... For Consumers Consumer Information by Audience For Women Sleep Problems Share Tweet Linkedin Pin it More sharing ... PDF 474KB) En Español Medicines to Help You Sleep Tips for Better Sleep Basic Facts about Sleep ...

  6. Sleep Quiz

    MedlinePlus

    ... on. Photo: iStock Take the National Center on Sleep Disorders Research Sleep Quiz TRUE OR FALSE ? _____1. Sleep ... sleepy during the day, you may have a sleep disorder. _____4. Opening the car window or turning the ...

  7. Sleep Disorders

    MedlinePlus

    ... have had enough sleep? You might have a sleep disorder. The most common kinds are Insomnia - a hard ... problems called parasomnias. There are treatments for most sleep disorders. Sometimes just having regular sleep habits can help.

  8. Sleeping worries away or worrying away sleep? Physiological evidence on sleep-emotion interactions.

    PubMed

    Talamini, Lucia M; Bringmann, Laura F; de Boer, Marieke; Hofman, Winni F

    2013-01-01

    Recent findings suggest that sleep might serve a role in emotional coping. However, most findings are based on subjective reports of sleep quality, while the relation with underlying sleep physiology is still largely unknown. In this study, the impact of an emotionally distressing experience on the EEG correlates of sleep was assessed. In addition, the association between sleep physiological parameters and the extent of emotional attenuation over sleep was determined. The experimental set up involved presentation of an emotionally neutral or distressing film fragment in the evening, followed by polysomnographic registration of undisturbed, whole-night sleep and assessment of emotional reactivity to film cues on the next evening. We found that emotional distress induced mild sleep deterioration, but also an increase in the proportion of slow wave sleep (SWS) and altered patterning of rapid eye movement (REM) sleep. Indeed, while REM sleep occurrence normally increases over the course of the night, emotional distress flattened this distribution and correlated with an increased number of REM periods. While sleep deterioration was negatively associated to emotional attenuation over sleep, the SWS response was positively related to such attenuation and may form part of a compensatory response to the stressor. Interestingly, trait-like SWS characteristics also correlated positively with the extent of emotion attenuation over sleep. The combined results provide strong evidence for an intimate reciprocal relation between sleep physiology and emotional processing. Moreover, individual differences in subjects' emotional and sleep responses suggest there may be a coupling of certain emotion and sleep traits into distinct emotional sleep types. PMID:23671601

  9. Habitual sleep length and patterns of recovery sleep after 24 hour and 36 hour sleep deprivation.

    PubMed

    Benoit, O; Foret, J; Bouard, G; Merle, B; Landau, J; Marc, M E

    1980-12-01

    Five long sleepers (LS) and 5 short sleepers (SS) were selected from 310 medical students. Nine regular sleepers (RS) were used as a control. The sleep was recorded during 3 reference nights, one recovery night after a 36 h sleep deprivation (R2), one morning sleep after a 24 h sleep deprivation (D1) and the night following D1(R1). According to previous data slow wave sleep (SWS) amounts were the same in the 3 groups while stage 2 and paradoxical sleep (PS) amounts increased with the sleep duration. The hourly distribution of intervening wakefulness and SWS were similar for all groups. When compared to RS or SS the hourly distribution in LS of PS was lower until the sixth hour. As a function of experimental conditions, sleep patterns of LS were the most affected. In R2 the sleep of LS more closely resembled that of RS or SS than in reference nights, while in R1 LS' sleep was the most disturbed. Morning sleep durations were very similar for all groups, but in LS intervening wakefulness was increased and PS was decreased when compared to RS and SS. Negative correlations (Spearman rank test) were found between the morning increase of body temperature after a sleep-deprived night and both TST and PS durations. In all recorded sleep periods, SWS amounts were positively correlated with prior wakefulness duration and the PS amount with TST. PMID:6160990

  10. Do birds sleep in flight?

    NASA Astrophysics Data System (ADS)

    Rattenborg, Niels C.

    2006-09-01

    The following review examines the evidence for sleep in flying birds. The daily need to sleep in most animals has led to the common belief that birds, such as the common swift ( Apus apus), which spend the night on the wing, sleep in flight. The electroencephalogram (EEG) recordings required to detect sleep in flight have not been performed, however, rendering the evidence for sleep in flight circumstantial. The neurophysiology of sleep and flight suggests that some types of sleep might be compatible with flight. As in mammals, birds exhibit two types of sleep, slow-wave sleep (SWS) and rapid eye-movement (REM) sleep. Whereas, SWS can occur in one or both brain hemispheres at a time, REM sleep only occurs bihemispherically. During unihemispheric SWS, the eye connected to the awake hemisphere remains open, a state that may allow birds to visually navigate during sleep in flight. Bihemispheric SWS may also be possible during flight when constant visual monitoring of the environment is unnecessary. Nevertheless, the reduction in muscle tone that usually accompanies REM sleep makes it unlikely that birds enter this state in flight. Upon landing, birds may need to recover the components of sleep that are incompatible with flight. Periods of undisturbed postflight recovery sleep may be essential for maintaining adaptive brain function during wakefulness. The recent miniaturization of EEG recording devices now makes it possible to measure brain activity in flight. Determining if and how birds sleep in flight will contribute to our understanding of a largely unexplored aspect of avian behavior and may also provide insight into the function of sleep.

  11. Update of sleep alterations in depression

    PubMed Central

    Medina, Andrés Barrera; Lechuga, DeboraYoaly Arana; Escandón, Oscar Sánchez; Moctezuma, Javier Velázquez

    2014-01-01

    Sleep disturbances in depression are up to 70%. Patients frequently have difficulty in falling asleep, frequent awakenings during the night and non-restorative sleep. Sleep abnormalities in depression are mainly characterized by increased rapid eye movement (REM) sleep and reduced slow wave sleep. Among the mechanisms of sleep disturbances in depression are hyperactivation of the hypothalamic-pituitary-adrenal axis, CLOCK gene polymorphism and primary sleep disorders. The habenula is a structure regulating the activities of monoaminergic neurons in the brain. The hyperactivation of the habenula has also been implicated, together with sleep disturbances, in depression. The presence of depression in primary sleep disorders is common. Sleep disturbances treatment include pharmacotherapy or Cognitive Behavioral Therapy. PMID:26483922

  12. Nap sleep spindle correlates of intelligence

    PubMed Central

    Ujma, Péter P.; Bódizs, Róbert; Gombos, Ferenc; Stintzing, Johannes; Konrad, Boris N.; Genzel, Lisa; Steiger, Axel; Dresler, Martin

    2015-01-01

    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. PMID:26607963

  13. EEG microstates of wakefulness and NREM sleep.

    PubMed

    Brodbeck, Verena; Kuhn, Alena; von Wegner, Frederic; Morzelewski, Astrid; Tagliazucchi, Enzo; Borisov, Sergey; Michel, Christoph M; Laufs, Helmut

    2012-09-01

    EEG-microstates exploit spatio-temporal EEG features to characterize the spontaneous EEG as a sequence of a finite number of quasi-stable scalp potential field maps. So far, EEG-microstates have been studied mainly in wakeful rest and are thought to correspond to functionally relevant brain-states. Four typical microstate maps have been identified and labeled arbitrarily with the letters A, B, C and D. We addressed the question whether EEG-microstate features are altered in different stages of NREM sleep compared to wakefulness. 32-channel EEG of 32 subjects in relaxed wakefulness and NREM sleep was analyzed using a clustering algorithm, identifying the most dominant amplitude topography maps typical of each vigilance state. Fitting back these maps into the sleep-scored EEG resulted in a temporal sequence of maps for each sleep stage. All 32 subjects reached sleep stage N2, 19 also N3, for at least 1 min and 45 s. As in wakeful rest we found four microstate maps to be optimal in all NREM sleep stages. The wake maps were highly similar to those described in the literature for wakefulness. The sleep stage specific map topographies of N1 and N3 sleep showed a variable but overall relatively high degree of spatial correlation to the wake maps (Mean: N1 92%; N3 87%). The N2 maps were the least similar to wake (mean: 83%). Mean duration, total time covered, global explained variance and transition probabilities per subject, map and sleep stage were very similar in wake and N1. In wake, N1 and N3, microstate map C was most dominant w.r.t. global explained variance and temporal presence (ratio total time), whereas in N2 microstate map B was most prominent. In N3, the mean duration of all microstate maps increased significantly, expressed also as an increase in transition probabilities of all maps to themselves in N3. This duration increase was partly--but not entirely--explained by the occurrence of slow waves in the EEG. The persistence of exactly four main microstate

  14. CONTROL OF SLEEP AND WAKEFULNESS

    PubMed Central

    Brown, Ritchie E.; Basheer, Radhika; McKenna, James T.; Strecker, Robert E.; McCarley, Robert W.

    2013-01-01

    This review summarizes the brain mechanisms controlling sleep and wakefulness. Wakefulness promoting systems cause low-voltage, fast activity in the electroencephalogram (EEG). Multiple interacting neurotransmitter systems in the brain stem, hypothalamus, and basal forebrain converge onto common effector systems in the thalamus and cortex. Sleep results from the inhibition of wake-promoting systems by homeostatic sleep factors such as adenosine and nitric oxide and GABAergic neurons in the preoptic area of the hypothalamus, resulting in large-amplitude, slow EEG oscillations. Local, activity-dependent factors modulate the amplitude and frequency of cortical slow oscillations. Non-rapid-eye-movement (NREM) sleep results in conservation of brain energy and facilitates memory consolidation through the modulation of synaptic weights. Rapid-eye-movement (REM) sleep results from the interaction of brain stem cholinergic, aminergic, and GABAergic neurons which control the activity of glutamatergic reticular formation neurons leading to REM sleep phenomena such as muscle atonia, REMs, dreaming, and cortical activation. Strong activation of limbic regions during REM sleep suggests a role in regulation of emotion. Genetic studies suggest that brain mechanisms controlling waking and NREM sleep are strongly conserved throughout evolution, underscoring their enormous importance for brain function. Sleep disruption interferes with the normal restorative functions of NREM and REM sleep, resulting in disruptions of breathing and cardiovascular function, changes in emotional reactivity, and cognitive impairments in attention, memory, and decision making. PMID:22811426

  15. GABAB Receptors, Schizophrenia and Sleep Dysfunction

    PubMed Central

    Kantrowitz, Joshua; Citrome, Leslie; Javitt, Daniel

    2016-01-01

    Evidence for an intrinsic relationship between sleep, cognition and the symptomatic manifestations of schizophrenia is accumulating. This review presents evidence for the possible utility of GABAB receptor agonists for the treatment of subjective and objective sleep abnormalities related to schizophrenia. At the phenotypic level, sleep disturbance occurs in 16–30% of patients with schizophrenia and is related to reduced quality of life and poor coping skills. On the neurophysiological level, studies suggest that sleep deficits reflect a core component of schizophrenia. Specifically, slow-wave sleep deficits, which are inversely correlated with cognition scores, are seen. Moreover, sleep plays an increasingly well documented role in memory consolidation in schizophrenia. Correlations of slow-wave sleep deficits with impaired reaction time and declarative memory have also been reported. Thus, both behavioural insomnia and sleep architecture are critical therapeutic targets in patients with schizophrenia. However, long-term treatment with antipsychotics often results in residual sleep dysfunction and does not improve slow-wave sleep, and adjunctive GABAA receptor modulators, such as benzodiazepines and zolpidem, can impair sleep architecture and cognition in schizophrenia. GABAB receptor agonists have therapeutic potential in schizophrenia. These agents have minimal effect on rapid eye movement sleep while increasing slow-wave sleep. Preclinical associations with increased expression of genes related to slow-wave sleep production and circadian rhythm function have also been reported. GABAB receptor deficits result in a sustained hyperdopaminergic state and can be reversed by a GABAB receptor agonist. Genetic, postmortem and electrophysiological studies also associate GABAB receptors with schizophrenia. While studies thus far have not shown significant effects, prior focus on the use of GABAB receptor agonists has been on the positive symptoms of schizophrenia, with

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

    PubMed Central

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

    2015-01-01

    Objective: 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. Design: 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). Setting: The study was set in an inpatient clinical research suite. Participants: Healthy, good-sleeping men and women were included. Measurement and Results: 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). Conclusions: 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. Citation: Finan PH, Quartana PJ, Smith MT. The effects of sleep continuity disruption on positive mood and sleep architecture in healthy adults. SLEEP 2015;38(11):1735–1742. PMID:26085289

  17. Sleep Quiz

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Sleep Quiz Past Issues / Summer 2007 Table of Contents ... on. Photo: iStock Take the National Center on Sleep Disorders Research Sleep Quiz TRUE OR FALSE ? _____1. ...

  18. Sleep Quiz

    MedlinePlus

    ... Home » About the NHLBI » Organization » National Center on Sleep Disorders Research (NCSDR) » Patient & Public Information » Sleep Quiz National Center on Sleep Disorders Research Research Professional Education Patient & Public Information Communications ...

  19. Sleep Disorders in Postmenopausal Women

    PubMed Central

    Jehan, Shazia; Masters-Isarilov, Alina; Salifu, Idoko; Zizi, Ferdinand; Jean-Louis, Girardin; Pandi-Perumal, Seithikurippu R; Gupta, Ravi; Brzezinski, Amnon; McFarlane, Samy I

    2015-01-01

    One of the core symptoms of the menopausal transition is sleep disturbance. Peri-menopausal women often complain of difficulties initiating and/or maintaining sleep with frequent nocturnal and early morning awakenings. Factors that may play a role in this type of insomnia include vasomotor symptoms, changing reproductive hormone levels, circadian rhythm abnormalities, mood disorders, coexistent medical conditions, and lifestyle. Other common sleep problems in this age group, such as obstructive sleep apnea and restless leg syndrome, can also worsen the sleep quality. Exogenous melatonin use reportedly induces drowsiness and sleep and may ameliorate sleep disturbances, including the nocturnal awakenings associated with old age and the menopausal transition. Recently, more potent melatonin analogs (selective melatonin-1 (MT1) and melatonin-2 (MT2) receptor agonists) with prolonged effects and slow-release melatonin preparations have been developed. They were found effective in increasing total sleep time and sleep efficiency as well as in reducing sleep latency in insomnia patients. The purpose of this review is to give an overview on the changes in hormonal status to sleep problems among menopausal and postmenopausal women. PMID:26512337

  20. Sleep and cardiac rhythm in the gray seal.

    PubMed

    Ridgway, S H; Harrison, R J; Joyce, P L

    1975-02-14

    Telemetric studies of electroencephalograms, electrocardiograms, and electroculograms and concurrent observations of behavior revealed that seals can sleep underwater, on the surface, or while hauled out. Rapid eye movement preceded slow wave sleep and was accompanied by increased respiratory rate and rhythmic tachycardia. While slow wave sleep occurred under all sleep conditions, rapid eye movement occurred only when a seal was hanging at the water surface or hauled out, never underwater. PMID:163484

  1. Sleep, Torpor and Memory Impairment

    NASA Astrophysics Data System (ADS)

    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.

  2. [Sleep psychiatry].

    PubMed

    Chiba, Shigeru

    2013-01-01

    Sleep disorders are serious issues in modern society. There has been marked scientific interest in sleep for a century, with the discoveries of the electrical activity of the brain (EEG), sleep-wake system, rapid eye movement (REM) sleep, and circadian rhythm system. Additionally, the advent of video-polysomnography in clinical research has revealed some of the consequences of disrupted sleep and sleep deprivation in psychiatric disorders. Decades of clinical research have demonstrated that sleep disorders are intimately tied to not only physical disease (e. g., lifestyle-related disease) but psychiatric illness. According to The International Classification of Sleep Disorders (2005), sleep disorders are classified into 8 major categories: 1) insomnia, 2) sleep-related breathing disorders, 3) hypersomnias of central origin, 4) circadian rhythm sleep disorders, 5) parasomnias, 6) sleep-related movement disorders, 7) isolated symptoms, and 8) other sleep disorders. Several sleep disorders, including obstructive sleep apnea syndrome, restless legs syndrome, periodic limb movement disorder, sleepwalking, REM sleep behavior disorder, and narcolepsy, may be comorbid or possibly mimic numerous psychiatric disorders, and can even occur due to psychiatric pharmacotherapy. Moreover, sleep disorders may exacerbate underlying psychiatric disorders when left untreated. Therefore, psychiatrists should pay attention to the intimate relationship between sleep disorders and psychiatric symptoms. Sleep psychiatry is an academic field focusing on interrelations between sleep medicine and psychiatry. This mini-review summarizes recent findings in sleep psychiatry. Future research on the bidirectional relation between sleep disturbance and psychiatric symptoms will shed light on the pathophysiological view of psychiatric disorders and sleep disorders. PMID:24050022

  3. Sleep and Chronic Disease

    MedlinePlus

    ... CDC Cancel Submit Search The CDC Sleep and Sleep Disorders Note: Javascript is disabled or is not supported ... CDC.gov . Sleep About Us About Sleep Key Sleep Disorders Sleep and Chronic Disease How Much Sleep Do ...

  4. Sleep smart—optimizing sleep for declarative learning and memory

    PubMed Central

    Feld, Gordon B.; Diekelmann, Susanne

    2015-01-01

    The last decade has witnessed a spurt of new publications documenting sleep's essential contribution to the brains ability to form lasting memories. For the declarative memory domain, slow wave sleep (the deepest sleep stage) has the greatest beneficial effect on the consolidation of memories acquired during preceding wakefulness. The finding that newly encoded memories become reactivated during subsequent sleep fostered the idea that reactivation leads to the strengthening and transformation of the memory trace. According to the active system consolidation account, trace reactivation leads to the redistribution of the transient memory representations from the hippocampus to the long-lasting knowledge networks of the cortex. Apart from consolidating previously learned information, sleep also facilitates the encoding of new memories after sleep, which probably relies on the renormalization of synaptic weights during sleep as suggested by the synaptic homeostasis theory. During wakefulness overshooting potentiation causes an imbalance in synaptic weights that is countered by synaptic downscaling during subsequent sleep. This review briefly introduces the basic concepts and central findings of the research on sleep and memory, and discusses implications of this lab-based work for everyday applications to make the best possible use of sleep's beneficial effect on learning and memory. PMID:26029150

  5. A Multistudy Analysis of the Effects of Early Cocaine Abstinence on Sleep

    PubMed Central

    Matuskey, D; Pittman, B; Forselius, E; Malison, RT; Morgan, PT

    2010-01-01

    Objective To describe the sleep patterns of early cocaine abstinence in chronic users by polysomnographic and subjective measures. Methods 28 cocaine-dependent participants (ages 24-55) underwent polysomnographic sleep (PSG) recording on the 1st, 2nd and 3rd weeks of abstinence on a research dedicated inpatient facility. Objective measures of total sleep time, total REM time, slow wave sleep, sleep efficiency and a subjective measure (sleep quality) along with demographic data were collected from three different long term research studies over a five year period. Data were reanalyzed to allow greater statistical power for comparisons. Results Progressive weeks of abstinence had main effects on all assessed PSG sleep measures showing decreased total sleep time, REM sleep, stage 1 and 2 sleep, and sleep efficiency; increases in sleep onset and REM latencies and a slight increase in slow-wave sleep time were also present. Total sleep time and slow wave sleep were negatively associated with years of cocaine use. Total sleep time was positively associated with the amount of current ethanol use. Sex differences were found with females having more total REM time and an increase at a near significance level in slow wave sleep. Subjective measures were reported as improving with increasing abstinence over the same time period. Conclusions Chronic cocaine users show a general deterioration in objective sleep measures over a three-week period despite an increase in subjective overall sleep quality providing further evidence for “occult insomnia” during early cocaine abstinence. PMID:21144676

  6. Effects of thermal environment on sleep and circadian rhythm

    PubMed Central

    2012-01-01

    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. PMID:22738673

  7. Infragranular layers lead information flow during slow oscillations according to information directionality indicators.

    PubMed

    Amigó, J M; Monetti, R; Tort-Colet, N; Sanchez-Vives, M V

    2015-08-01

    The recurrent circuitry of the cerebral cortex generates an emergent pattern of activity that is organized into rhythmic periods of firing and silence referred to as slow oscillations (ca 1 Hz). Slow oscillations not only are dominant during slow wave sleep and deep anesthesia, but also can be generated by the isolated cortical network in vitro, being a sort of default activity of the cortical network. The cortex is densely and reciprocally connected with subcortical structures and, as a result, the slow oscillations in situ are the result of an interplay between cortex and thalamus. Due to this reciprocal connectivity and interplay, the mechanism responsible for the initiation of waves in the corticothalamocortical loop during slow oscillations is still a matter of debate. It was our objective to determine the directionality of the information flow between different layers of the cortex and the connected thalamus during spontaneous activity. With that purpose we obtained multilayer local field potentials from the rat visual cortex and from its connected thalamus, the lateral geniculate nucleus, during deep anaesthesia. We analyzed directionality of information flow between thalamus, cortical infragranular layers (5 and 6) and supragranular layers (2/3) by means of three information theoretical indicators: transfer entropy, symbolic transfer entropy and transcript mutual information. These three indicators coincided in finding that infragranular layers lead the information flow during slow oscillations both towards supragranular layers and towards the thalamus. PMID:25966805

  8. Modelling changes in sleep timing and duration across the lifespan: Changes in circadian rhythmicity or sleep homeostasis?

    PubMed

    Skeldon, Anne C; Derks, Gianne; Dijk, Derk-Jan

    2016-08-01

    Sleep changes across the lifespan, with a delay in sleep timing and a reduction in slow wave sleep seen in adolescence, followed by further reductions in slow wave sleep but a gradual drift to earlier timing during healthy ageing. The mechanisms underlying changes in sleep timing are unclear: are they primarily related to changes in circadian processes, or to a reduction in the neural activity dependent build up of homeostatic sleep pressure during wake, or both? We review existing studies of age-related changes to sleep and explore how mathematical models can explain observed changes. Model simulations show that typical changes in sleep timing and duration, from adolesence to old age, can be understood in two ways: either as a consequence of a simultaneous reduction in the amplitude of the circadian wake-propensity rhythm and the neural activity dependent build-up of homeostatic sleep pressure during wake; or as a consequence of reduced homeostatic sleep pressure alone. A reduction in the homeostatic pressure also explains greater vulnerability of sleep to disruption and reduced daytime sleep-propensity in healthy ageing. This review highlights the important role of sleep homeostasis in sleep timing. It shows that the same phenotypic response may have multiple underlying causes, and identifies aspects of sleep to target to correct delayed sleep in adolescents and advanced sleep in later life. PMID:26545247

  9. Sleep loss and sleepiness: current issues.

    PubMed

    Balkin, Thomas J; Rupp, Tracy; Picchioni, Dante; Wesensten, Nancy J

    2008-09-01

    Awareness of the consequences of sleep loss and its implications for public health and safety is increasing. Sleep loss has been shown to generally impair the entire spectrum of mental abilities, ranging from simple psychomotor performance to executive mental functions. Sleep loss may also impact metabolism in a manner that contributes to obesity and its attendant health consequences. Although objective measures of alertness and performance remain degraded, individuals subjectively habituate to chronic partial sleep loss (eg, sleep restriction), and recovery from this type of sleep loss is slow, factors that may help to explain the observation that many individuals in the general population are chronically sleep restricted. Individual differences in habitual sleep duration appear to be a trait-like characteristic that is determined by several factors, including genetic polymorphisms. PMID:18779203

  10. Possible influence of AMPD1 on cholinergic neurotransmission and sleep.

    PubMed

    Buyse, Bertien; Van Damme, Philip; Belge, Catharina; Testelmans, Dries

    2016-02-01

    It is known that adenosine excess due to monophosphate deaminase deficiency (AMPD1) can be linked to muscle problems. Recently, Perumal et al., 2014 reported a first case of possible impact of AMPD1 on sleep, REM sleep and cholinergic neurotransmission. We report a second patient with similar sleep complaints: long sleep duration with residual daytime sleepiness and a need to sleep after exercise. On polysomnography we observed a long sleep duration, with high sleep efficiency and a SOREMP; on MSLT a shortened sleep latency and 4 SOREMPS were observed. Frequency power spectral heart rate analysis during slow wave sleep, REM sleep and wakefulness revealed an increased parasympathetic tone. In conclusion, AMPD1 could have a profound influence on cholinergic neurotransmission and sleep; further studies are mandatory. PMID:26439223

  11. Analysis of Sleep Parameters in Patients with Obstructive Sleep Apnea Studied in a Hospital vs. a Hotel-Based Sleep Center

    PubMed Central

    Hutchison, Kimberly N.; Song, Yanna; Wang, Lily; Malow, Beth A.

    2008-01-01

    Background: Polysomnography is associated with changes in sleep architecture called the first-night effect. This effect is believed to result from sleeping in an unusual environment and the technical equipment used to study sleep. Sleep experts hope to decrease this variable by providing a more familiar, comfortable atmosphere for sleep testing through hotel-based sleep centers. In this study, we compared the sleep parameters of patients studied in our hotel-based and hospital-based sleep laboratories. Methods: We retrospectively reviewed polysomnograms completed in our hotel-based and hospital-based sleep laboratories from August 2003 to July 2005. All patients were undergoing evaluation for obstructive sleep apnea. Hospital-based patients were matched for age and apnea-hypopnea index with hotel-based patients. We compared the sleep architecture changes associated with the first-night effect in the two groups. The associated conditions and symptoms listed on the polysomnography referral forms are also compared. Results: No significant differences were detected between the two groups in sleep onset latency, sleep efficiency, REM sleep latency, total amount of slow wave sleep (NREM stages 3 and 4), arousal index, and total stage 1 sleep. Conclusions: This pilot study failed to show a difference in sleep parameters associated with the first-night effect in patients undergoing sleep studies in our hotel and hospital-based sleep laboratories. Future studies need to compare the first-night effect in different sleep disorders, preferably in multi-night recordings. Citation: Hutchison KN; Song Y; Wang L; Malow BA. Analysis of sleep parameters in patients with obstructive sleep apnea studied in a hospital vs. A hotel-based sleep center. J Clin Sleep Med 2008;4(2):119–122. PMID:18468309

  12. The disturbance by road traffic noise of the sleep of young male adults as recorded in the home

    NASA Astrophysics Data System (ADS)

    Eberhardt, J. L.; Akselsson, K. R.

    1987-05-01

    Primary effects of road traffic noise on sleep, as derived from EEG, EOG, and EMG, were studied for seven young males (aged 21-27) in their homes along roads with heavy traffic during the night. A more quiet experimental condition was obtained by mounting sound-insulating material in the window openings, thus reducing the interiors noise level by an average of 8 dB(A). The present investigation shows that the subjects had not become completely habituated to the noise, although they had lived at least a year at their residences. The noise reduction caused an earlier onset and a prolonged duration of slow was sleep. No effects on REM sleep were seen. The subjective sleep quality was significantly correlated to the noise dose. The equivalent sound pressure level ( L eq) did not give the most adequate noise dose description. Better characterizations of the noise exposure were found in the number of car per night producing maximum sound pressure levels exceeding 50 or 55 dB(A) in the bedroom. Arousal reactions of type "body movements" and "changes towards lighter sleep" were induced by the noise of car passage but the percentage of cars inducing an effect was only <2% and <0·2% for the two types of reactions, respectively. The number of spontaneous body movements and sleep stage changes per night showed an increase during the more quiet nights as compared to the noisy nights. The sensitivity to arousal reactions was significantly lower in the present field study than the in the laboratory experiments. A description of the continuous sleep process by a few distinct "sleep stages" is too crude a tool for the detection of the rather subtle changes in the sleeping pattern caused by noise. In the present study an increased sensitivity in the analysis was obtained by dividing stage 2 into three substages.

  13. Race and Financial Strain are Independent Correlates of Sleep in Midlife Women: The SWAN Sleep Study

    PubMed Central

    Hall, Martica H.; Matthews, Karen A.; Kravitz, Howard M.; Gold, Ellen B.; Buysse, Daniel J.; Bromberger, Joyce T.; Owens, Jane F.; Sowers, MaryFran

    2009-01-01

    Study Objectives: To examine racial differences in sleep in a large cohort of midlife women and to evaluate whether indices of socioeconomic status (SES) are associated with racial differences in sleep. Design: Cross-sectional study. Setting: Participants' homes. Participants: Caucasian (n = 171), African American (n = 138) and Chinese women (n = 59). Interventions: None. Measurements: Sleep quality was assessed with the Pittsburgh Sleep Quality Index. Polysomnographically assessed sleep duration, continuity, architecture, and NREM electroencephalograhic (EEG) power were calculated over multiple nights. Sleep disordered breathing and periodic leg movements were measured on a separate night. Linear regression analysis was used to model the independent and synergistic effects of race and SES on sleep after adjusting for other factors that impact sleep in midlife women. Indices of SES were self-reported educational attainment and financial strain. Results: Sleep was worse in African American women than Caucasian participants as measured by self-report, visual sleep stage scoring, and NREM EEG power. Slow wave sleep differences were also observed between Chinese and Caucasian participants. Racial differences persisted after adjustment for indices of SES. Although educational attainment was unrelated to sleep, financial strain was associated with decreased sleep quality and lower sleep efficiency. Financial strain-by-race interactions were not statistically significant, suggesting that financial strain has additive effects on sleep, independent of race. Conclusions: Independent relationships between race and financial strain with sleep were observed despite statistical adjustment for other factors that might account for these relationships. Results do not suggest that assessed indices of SES moderate the race-sleep relationship, perhaps due to too few women of low SES in the study. Citation: Hall MH; Matthews KA; Kravitz HM; Gold EB; Buysse DJ; Bromberger JT; Owens JF

  14. Sleep and Epilepsy: Strange Bedfellows No More

    PubMed Central

    St. Louis, Erik K.

    2012-01-01

    Ancient philosophers and theologians believed that altered consciousness freed the mind to prophesy the future, equating sleep with seizures. Only recently has the bidirectional influences of epilepsy and sleep upon one another received more substantive analysis. This article reviews the complex and increasingly recognized interrelationships between sleep and epilepsy. NREM sleep differentially activates interictal epileptiform discharges during slow wave (N3) sleep, while ictal seizure events occur more frequently during light NREM stages N1 and N2. The most commonly encountered types of sleep-related epilepsies (those with preferential occurrence during sleep or following arousal) include frontal and temporal lobe partial epilepsies in adults, and benign epilepsy of childhood with centrotemporal spikes (benign rolandic epilepsy) and juvenile myoclonic epilepsy in children and adolescents. Comorbid sleep disorders are frequent in patients with epilepsy, particularly obstructive sleep apnea in refractory epilepsy patients which may aggravate seizure burden, while treatment with nasal continuous positive airway pressure often improves seizure frequency. Distinguishing nocturnal events such as NREM parasomnias (confusional arousals, sleep walking, and night terrors), REM parasomnias including REM sleep behavior disorder, and nocturnal seizures if frequently difficult and benefits from careful history taking and video-EEG-polysomnography in selected cases. Differentiating nocturnal seizures from primary sleep disorders is essential for determining appropriate therapy, and recognizing co-existent sleep disorders in patients with epilepsy may improve their seizure burden and quality of life. PMID:23539488

  15. Sleep and Epilepsy: Strange Bedfellows No More.

    PubMed

    St Louis, Erik K

    2011-09-01

    Ancient philosophers and theologians believed that altered consciousness freed the mind to prophesy the future, equating sleep with seizures. Only recently has the bidirectional influences of epilepsy and sleep upon one another received more substantive analysis. This article reviews the complex and increasingly recognized interrelationships between sleep and epilepsy. NREM sleep differentially activates interictal epileptiform discharges during slow wave (N3) sleep, while ictal seizure events occur more frequently during light NREM stages N1 and N2. The most commonly encountered types of sleep-related epilepsies (those with preferential occurrence during sleep or following arousal) include frontal and temporal lobe partial epilepsies in adults, and benign epilepsy of childhood with centrotemporal spikes (benign rolandic epilepsy) and juvenile myoclonic epilepsy in children and adolescents. Comorbid sleep disorders are frequent in patients with epilepsy, particularly obstructive sleep apnea in refractory epilepsy patients which may aggravate seizure burden, while treatment with nasal continuous positive airway pressure often improves seizure frequency. Distinguishing nocturnal events such as NREM parasomnias (confusional arousals, sleep walking, and night terrors), REM parasomnias including REM sleep behavior disorder, and nocturnal seizures if frequently difficult and benefits from careful history taking and video-EEG-polysomnography in selected cases. Differentiating nocturnal seizures from primary sleep disorders is essential for determining appropriate therapy, and recognizing co-existent sleep disorders in patients with epilepsy may improve their seizure burden and quality of life. PMID:23539488

  16. Sleep disorders - overview

    MedlinePlus

    ... Narcolepsy; Hypersomina; Daytime sleepiness; Sleep rhythm; Sleep disruptive behaviors; Jet lag ... a regular sleep schedule (sleep rhythm problem) Unusual behaviors during sleep (sleep-disruptive behaviors) PROBLEMS FALLING AND ...

  17. Sleep Eduction: Treatment & Therapy

    MedlinePlus

    ... Benefits Side Effects Variations Tips Healthy Sleep Habits Sleep Disorders by Category Insomnias Insomnia Child Insomnia Short Sleeper Hypersomnias Narcolepsy Insufficient Sleep Syndrome Long Sleeper Sleep Breathing Disorders Sleep Apnea Snoring Central Sleep Apnea Overview & Facts ...

  18. Sleep Talking (Somniloquy)

    MedlinePlus

    ... Benefits Side Effects Variations Tips Healthy Sleep Habits Sleep Disorders by Category Insomnias Insomnia Child Insomnia Short Sleeper Hypersomnias Narcolepsy Insufficient Sleep Syndrome Long Sleeper Sleep Breathing Disorders Sleep Apnea Snoring Central Sleep Apnea Overview & Facts ...

  19. Sleep Apnea Information Page

    MedlinePlus

    ... is Sleep Apnea? Sleep apnea is a common sleep disorder characterized by brief interruptions of breathing during sleep. ... better ways to prevent, treat, and ultimately cure sleep disorders, such as sleep apnea. NIH Patient Recruitment for ...

  20. Healthy Sleep Habits

    MedlinePlus

    ... Benefits Side Effects Variations Tips Healthy Sleep Habits Sleep Disorders by Category Insomnias Insomnia Child Insomnia Short Sleeper Hypersomnias Narcolepsy Insufficient Sleep Syndrome Long Sleeper Sleep Breathing Disorders Sleep Apnea Snoring Central Sleep Apnea Overview & Facts ...

  1. Changing your sleep habits

    MedlinePlus

    Insomnia - sleep habits; Sleep disorder - sleep habits; Problems falling asleep; Sleep hygiene ... People who have insomnia are often worried about getting enough sleep. The more they try to sleep, the more frustrated and upset they ...

  2. Awakening from sleep.

    PubMed

    Akerstedt, Torbjorn; Billiard, Michel; Bonnet, Michael; Ficca, Gianluca; Garma, Lucile; Mariotti, Maurizio; Salzarulo, Piero; Schulz, Hartmut

    2002-08-01

    Awakening is a crucial event for the organism. The transition from sleep to waking implies physiological processes which lead to a new behavioural state. Spontaneous awakenings have varying features which may change as a function of several factors. The latter include intrasleep architecture, circadian phase, time awake, age, or disordered sleep. Despite its clear theoretical and clinical importance, the topic of awakening (in humans) has received little attention so far. This contribution focuses on major issues which relate to awakening from both basic (experimental) and clinical research. Recent knowledge on neurophysiological mechanisms is reported. The experimental data which provide in the human suggestions on the regulation of awakening are discussed, mainly those concerning sleep architecture and homeostatic/circadian factors also in a life-span perspective, since age is a powerful factor which may influence awakening. Clinical contributions will examine two main sleep disorders: insomnia and hypersomnia. Daytime functioning is shown in insomniac patients and compared to other pathologies like sleep apnea. A final section evokes links between some types of night waking and psychological factors. PMID:12531132

  3. EDITORIAL: Slow light Slow light

    NASA Astrophysics Data System (ADS)

    Boyd, Robert; Hess, Ortwin; Denz, Cornelia; Paspalakis, Emmanuel

    2010-10-01

    Research into slow light began theoretically in 1880 with the paper [1] of H A Lorentz, who is best known for his work on relativity and the speed of light. Experimental work started some 60 years later with the work of S L McCall and E L Hahn [2] who explored non-linear self-induced transparency in ruby. This field of research has burgeoned in the last 10 years, starting with the work of L Vestergaard Hau and coworkers on slow light via electromagnetically induced transparency in a Bose-Einstein condensate [3]. Many groups are now able to slow light down to a few metres per second or even stop the motion of light entirely [4]. Today, slow light - or more often `slow and fast light' - has become its own vibrant field with a strongly increasing number of publications. In broad scope, slow light research can be categorized in terms of the sort of physical mechanism used to slow down the light. One sort of slow light makes use of material dispersion. This dispersion can be the natural dispersion of the ordinary refractive index or can be the frequency dependence of some nonlinear optical process, such as electromagnetically induced transparency, coherent population oscillations, stimulated light scattering, or four-wave mixing processes. The second sort of slow light makes use of the wavelength dependence of artificially structured materials, such as photonic crystals, optical waveguides, and collections of microresonators. Material systems in which slow light has been observed include metal vapours, rare-earth-doped materials, Raman and Brillioun gain media, photonic crystals, microresonators and, more recently, metamaterials. A common feature of all of these schemes is the presence of a sharp single resonance or multiple resonances produced by an atomic transition, a resonance in a photonic structure, or in a nonlinear optical process. Current applications of slow light include a series of attractive topics in optical information processing, such as optical data

  4. Sleep and olfactory cortical plasticity

    PubMed Central

    Barnes, Dylan C.; Wilson, Donald A.

    2014-01-01

    In many systems, sleep plays a vital role in memory consolidation and synaptic homeostasis. These processes together help store information of biological significance and reset synaptic circuits to facilitate acquisition of information in the future. In this review, we describe recent evidence of sleep-dependent changes in olfactory system structure and function which contribute to odor memory and perception. During slow-wave sleep, the piriform cortex becomes hypo-responsive to odor stimulation and instead displays sharp-wave activity similar to that observed within the hippocampal formation. Furthermore, the functional connectivity between the piriform cortex and other cortical and limbic regions is enhanced during slow-wave sleep compared to waking. This combination of conditions may allow odor memory consolidation to occur during a state of reduced external interference and facilitate association of odor memories with stored hedonic and contextual cues. Evidence consistent with sleep-dependent odor replay within olfactory cortical circuits is presented. These data suggest that both the strength and precision of odor memories is sleep-dependent. The work further emphasizes the critical role of synaptic plasticity and memory in not only odor memory but also basic odor perception. The work also suggests a possible link between sleep disturbances that are frequently co-morbid with a wide range of pathologies including Alzheimer’s disease, schizophrenia and depression and the known olfactory impairments associated with those disorders. PMID:24795585

  5. Sleep Apnea

    MedlinePlus

    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 ...

  6. Sleep Apnea

    MedlinePlus

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

  7. Dissociated wake-like and sleep-like electro-cortical activity during sleep.

    PubMed

    Nobili, Lino; Ferrara, Michele; Moroni, Fabio; De Gennaro, Luigi; Russo, Giorgio Lo; Campus, Claudio; Cardinale, Francesco; De Carli, Fabrizio

    2011-09-15

    Sleep is traditionally considered a global process involving the whole brain. However, recent studies have shown that sleep depth is not evenly distributed within the brain. Sleep disorders, such as sleepwalking, also suggest that EEG features of sleep and wakefulness might be simultaneously present in different cerebral regions. In order to probe the coexistence of dissociated (wake-like and sleep-like) electrophysiological behaviors within the sleeping brain, we analyzed intracerebral electroencephalographic activity drawn from sleep recordings of five patients with pharmacoresistant focal epilepsy without sleep disturbances, who underwent pre-surgical intracerebral electroencephalographic investigation. We applied spectral and wavelet transform analysis techniques to electroencephalographic data recorded from scalp and intracerebral electrodes localized within the Motor cortex (Mc) and the dorso-lateral Prefrontal cortex (dlPFc). The Mc showed frequent Local Activations (lasting from 5 to more than 60s) characterized by an abrupt interruption of the sleep electroencephalographic slow waves pattern and by the appearance of a wake-like electroencephalographic high frequency pattern (alpha and/or beta rhythm). Local activations in the Mc were paralleled by a deepening of sleep in other regions, as expressed by the concomitant increase of slow waves in the dlPFc and scalp electroencephalographic recordings. These results suggest that human sleep can be characterized by the coexistence of wake-like and sleep-like electroencephalographic patterns in different cortical areas, supporting the hypothesis that unusual phenomena, such as NREM parasomnias, could result from an imbalance of these two states. PMID:21718789

  8. Cortical Processing of Respiratory Afferent Stimuli during Sleep in Children with the Obstructive Sleep Apnea Syndrome

    PubMed Central

    Huang, Jingtao; Colrain, Ian M.; Melendres, M. Cecilia; Karamessinis, Laurie R.; Pepe, Michelle E.; Samuel, John M.; Abi-Raad, Ronald F.; Trescher, William H.; Marcus, Carole L.

    2008-01-01

    Study Objectives: Children with the obstructive sleep apnea syndrome (OSAS) have blunted upper airway responses to negative pressure, but the underlying cause remains unknown. Cortical processing of respiratory afferent information can be tested by measuring respiratory-related evoked potentials (RREPs). We hypothesized that children with OSAS have blunted RREP responses compared to normal children during sleep. Design: During sleep, RREPs were obtained from EEG electrodes Fz, Cz, Pz during stage 2 sleep, slow wave sleep (SWS), and REM sleep. RREPs were produced with multiple short occlusions of the upper airway. Setting: Sleep laboratory. Participants: 9 children with OSAS and 12 normal controls. Measurements and Results: Children with OSAS had significantly decreased evoked K-complex production in stage 2 sleep and slow wave sleep and significantly reduced RREP N350 and P900 components in slow wave sleep. There were no significant differences in any of the measured RREP components in stage 2 sleep, and the only REM difference was decreased P2 amplitude. Conclusions: Results indicate that in children with OSAS, cortical processing of respiratory-related information measured with RREPs persists throughout sleep; however, RREPs during SWS are blunted compared to those seen in control children. Possible causes for this difference include a congenital deficit in neural processing reflective of a predisposition to develop OSAS, or changes in the upper airway rendering the airway less capable of transducing pressure changes following occlusion. Further research is required to evaluate RREPs after effective surgical treatment of OSAS in children, in order to distinguish between these alternatives. Citation: Huang J; Colrain IM; Melendres MC; Karamessinis LR; Pepe ME; Samuel JM; Abi-Raad RF; Trescher WH; Marcus CL. Cortical processing of respiratory afferent stimuli during sleep in children with the obstructive sleep apnea syndrome. SLEEP 2007;31(3):403-410. PMID:18363317

  9. Synchronization Properties of Slow Cortical Oscillations

    NASA Astrophysics Data System (ADS)

    Takekawa, T.; Aoyagi, T.; Fukai, T.

    During slow-wave sleep, the brain shows slow oscillatory activity with remarkable long-range synchrony. Intracellular recordings show that the slow oscillation consists of two phases: an textit{up} state and a textit{down} state. Deriving the phase-response function of simplified neuronal systems, we examine the synchronization properties on slow oscillations between the textit{up} state and the textit{down} state. As a result, the strange interaction functions are found in some parameter ranges. These functions indicate that the states with the smaller phase lag than a critical value are all stable.

  10. The Role of Sleep in Changing Our Minds: A Psychologist's Discussion of Papers on Memory Reactivation and Consolidation in Sleep

    ERIC Educational Resources Information Center

    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. Gender differences in sleep in older men and women.

    PubMed

    Guidozzi, F

    2015-10-01

    Sleep disturbances increase with increasing age in both males and females and become fairly common in the older community when compared to their younger counterparts. Even though these sleep disturbances increase with advancing age, there are nevertheless inherent differences in sleep disturbances between males and females. When compared to older men, older women will have a longer sleep latency (number of minutes it takes to fall asleep), more daytime sleepiness, will sleep about 20 min less per day, have less NREM stages 1 and 2 sleep, have more slow-wave sleep, and are more predisposed to REM sleep. Women have at least a 40% increased risk for developing insomnia, are at twice the risk for restless legs syndrome, will have different obstructive sleep apnea symptoms and more partial obstructions during sleep compared to men. They are also less likely to use antidepressants but will metabolize zolpidem 50% slower than men. PMID:26249643

  12. Role of cardiorespiratory synchronization and sleep physiology: effects on membrane potential in the restorative functions of sleep.

    PubMed

    Jerath, Ravinder; Harden, Kyler; Crawford, Molly; Barnes, Vernon A; Jensen, Mike

    2014-03-01

    Although sleep physiology has been extensively studied, many of the cellular processes that occur during sleep and the functional significance of sleep remain unclear. The degree of cardiorespiratory synchronization during sleep increases during the progression of slow-wave sleep (SWS). Autonomic nervous system (ANS) activity also assumes a pattern that correlates with the progression of sleep. The ANS is an integral part of physiologic processes that occur during sleep with the respective contribution of parasympathetic and sympathetic activity varying between different sleep stages. In our paper, we attempt to unify the activities of various physiologic systems, namely the cardiac, respiratory, ANS and brain, during sleep into a consolidated picture with particular attention to the membrane potential of neurons. In our unified model, we explore the potential of sleep to promote restorative processes in the brain. PMID:24548599

  13. Tips for Getting a Good Night's Sleep | NIH MedlinePlus the Magazine

    MedlinePlus

    ... Are You Sleep-Deprived? Tips for Getting a Good Night's Sleep Past Issues / Summer 2012 Table of Contents One ... slow down so you're more ready to sleep. Have a good sleeping environment. Get rid of anything in your ...

  14. How Sleep Activates Epileptic Networks?

    PubMed Central

    Halász, Peter

    2013-01-01

    Background. The relationship between sleep and epilepsy has been long ago studied, and several excellent reviews are available. However, recent development in sleep research, the network concept in epilepsy, and the recognition of high frequency oscillations in epilepsy and more new results may put this matter in a new light. Aim. The review address the multifold interrelationships between sleep and epilepsy networks and with networks of cognitive functions. Material and Methods. The work is a conceptual update of the available clinical data and relevant studies. Results and Conclusions. Studies exploring dynamic microstructure of sleep have found important gating mechanisms for epileptic activation. As a general rule interictal epileptic manifestations seem to be linked to the slow oscillations of sleep and especially to the reactive delta bouts characterized by A1 subtype in the CAP system. Important link between epilepsy and sleep is the interference of epileptiform discharges with the plastic functions in NREM sleep. This is the main reason of cognitive impairment in different forms of early epileptic encephalopathies affecting the brain in a special developmental window. The impairment of cognitive functions via sleep is present especially in epileptic networks involving the thalamocortical system and the hippocampocortical memory encoding system. PMID:24159386

  15. Sleep at high altitude: guesses and facts.

    PubMed

    Bloch, Konrad E; Buenzli, Jana C; Latshang, Tsogyal D; Ulrich, Silvia

    2015-12-15

    Lowlanders commonly report a poor sleep quality during the first few nights after arriving at high altitude. Polysomnographic studies reveal that reductions in slow wave sleep are the most consistent altitude-induced changes in sleep structure identified by visual scoring. Quantitative spectral analyses of the sleep electroencephalogram have confirmed an altitude-related reduction in the low-frequency power (0.8-4.6 Hz). Although some studies suggest an increase in arousals from sleep at high altitude, this is not a consistent finding. Whether sleep instability at high altitude is triggered by periodic breathing or vice versa is still uncertain. Overnight changes in slow wave-derived encephalographic measures of neuronal synchronization in healthy subjects were less pronounced at moderately high (2,590 m) compared with low altitude (490 m), and this was associated with a decline in sleep-related memory consolidation. Correspondingly, exacerbation of breathing and sleep disturbances experienced by lowlanders with obstructive sleep apnea during a stay at 2,590 m was associated with poor performance in driving simulator tests. These findings suggest that altitude-related alterations in sleep may adversely affect daytime performance. Despite recent advances in our understanding of sleep at altitude, further research is required to better establish the role of gender and age in alterations of sleep at different altitudes, to determine the influence of acclimatization and of altitude-related illness, and to uncover the characteristics of sleep in highlanders that may serve as a study paradigm of sleep in patients exposed to chronic hypoxia due to cardiorespiratory disease. PMID:26229000

  16. A Simplified In vitro Experimental Model Encompasses the Essential Features of Sleep.

    PubMed

    Colombi, Ilaria; Tinarelli, Federico; Pasquale, Valentina; Tucci, Valter; Chiappalone, Michela

    2016-01-01

    In this paper, we show that neuronal assemblies plated on Micro Electrode Arrays present synchronized, low frequency firing patterns similar to in vivo slow wave oscillations, which are a key parameter of sleep-like state. Although neuronal cultures lack the characteristic high-frequency waves of wakefulness, it is possible to modulate their spontaneous firing pattern through the administration of specific neurotransmitters such as acetylcholine. We thus stimulated the cortical cultures with an agonist of acetylcholine receptor, Carbachol, which caused a desynchronization of the spontaneous firing of the cultures. We recorded and monitored the cultures for a period of over 31 h. We analyzed the electrophysiological signals by exploiting novel methodological approaches, taking into account the different temporal scales of the recorded signals, and considering both spikes and local field potentials. Supporting the electrophysiological analysis results, gene expressions of targeted genes showed the activation of specific markers involved in sleep-wake rhythms. Our results demonstrate that the Carbachol treatment induces desynchronization of neuronal activity, altering sleep-like properties in an in vitro model. PMID:27458335

  17. A Simplified In vitro Experimental Model Encompasses the Essential Features of Sleep

    PubMed Central

    Colombi, Ilaria; Tinarelli, Federico; Pasquale, Valentina; Tucci, Valter; Chiappalone, Michela

    2016-01-01

    In this paper, we show that neuronal assemblies plated on Micro Electrode Arrays present synchronized, low frequency firing patterns similar to in vivo slow wave oscillations, which are a key parameter of sleep-like state. Although neuronal cultures lack the characteristic high-frequency waves of wakefulness, it is possible to modulate their spontaneous firing pattern through the administration of specific neurotransmitters such as acetylcholine. We thus stimulated the cortical cultures with an agonist of acetylcholine receptor, Carbachol, which caused a desynchronization of the spontaneous firing of the cultures. We recorded and monitored the cultures for a period of over 31 h. We analyzed the electrophysiological signals by exploiting novel methodological approaches, taking into account the different temporal scales of the recorded signals, and considering both spikes and local field potentials. Supporting the electrophysiological analysis results, gene expressions of targeted genes showed the activation of specific markers involved in sleep-wake rhythms. Our results demonstrate that the Carbachol treatment induces desynchronization of neuronal activity, altering sleep-like properties in an in vitro model. PMID:27458335

  18. Effects of Sleep Fragmentation on Sleep and Markers of Inflammation in Mice

    PubMed Central

    Trammell, Rita A; Verhulst, Steve; Toth, Linda A

    2014-01-01

    Many people in our society experience curtailment and disruption of sleep due to work responsibilities, care-giving, or life style choice. Delineating the health effect of acute and chronic disruptions in sleep is essential to raising awareness of and creating interventions to manage these prevalent concerns. To provide a platform for studying the health impact and underlying pathophysiologic mechanisms associated with inadequate sleep, we developed and characterized an approach to creating chronic disruption of sleep in laboratory mice. We used this method to evaluate how 3 durations of sleep fragmentation (SF) affect sleep recuperation and blood and lung analyte concentrations in male C57BL/6J mice. Mice housed in environmentally controlled chambers were exposed to automated SF for periods of 6, 12, or 24 h or for 12 h daily during the light (somnolent) phase for 4 sequential days. Sleep time, slow-wave amplitude, or bout lengths were significantly higher when uninterrupted sleep was permitted after each of the 3 SF durations. However, mice did not recover all of the lost slow-wave sleep during the subsequent 12- to 24-h period and maintained a net loss of sleep. Light-phase SF was associated with significant changes in serum and lung levels of some inflammatory substances, but these changes were not consistent or sustained. The data indicate that acute light-phase SF can result in a sustained sleep debt in mice and may disrupt the inflammatory steady-state in serum and lung. PMID:24512957

  19. Sleep Disorders Associated with Primary Mitochondrial Diseases

    PubMed Central

    Ramezani, Ryan J.; Stacpoole, Peter W.

    2014-01-01

    Study Objectives: Primary mitochondrial diseases are caused by heritable or spontaneous mutations in nuclear DNA or mitochondrial DNA. Such pathological mutations are relatively common in humans and may lead to neurological and neuromuscular complication that could compromise normal sleep behavior. To gain insight into the potential impact of primary mitochondrial disease and sleep pathology, we reviewed the relevant English language literature in which abnormal sleep was reported in association with a mitochondrial disease. Design: We examined publications reported in Web of Science and PubMed from February 1976 through January 2014, and identified 54 patients with a proven or suspected primary mitochondrial disorder who were evaluated for sleep disturbances. Measurements and Results: Both nuclear DNA and mitochondrial DNA mutations were associated with abnormal sleep patterns. Most subjects who underwent polysomnography had central sleep apnea, and only 5 patients had obstructive sleep apnea. Twenty-four patients showed decreased ventilatory drive in response to hypoxia and/or hypercapnia that was not considered due to weakness of the intrinsic muscles of respiration. Conclusions: Sleep pathology may be an underreported complication of primary mitochondrial diseases. The probable underlying mechanism is cellular energy failure causing both central neurological and peripheral neuromuscular degenerative changes that commonly present as central sleep apnea and poor ventilatory response to hypercapnia. Increased recognition of the genetics and clinical manifestations of mitochondrial diseases by sleep researchers and clinicians is important in the evaluation and treatment of all patients with sleep disturbances. Prospective population-based studies are required to determine the true prevalence of mitochondrial energy failure in subjects with sleep disorders, and conversely, of individuals with primary mitochondrial diseases and sleep pathology. Citation: Ramezani RJ

  20. Mammalian sleep

    NASA Astrophysics Data System (ADS)

    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.

  1. Alterations in sleep architecture in response to experimental sleep curtailment are associated with signs of positive energy balance

    PubMed Central

    Shechter, Ari; O'Keeffe, Majella; Roberts, Amy L.; Zammit, Gary K.; RoyChoudhury, Arindam

    2012-01-01

    Sleep reduction is associated with increased energy intake and weight gain, though few studies have explored the relationship between sleep architecture and energy balance measures in the context of experimental sleep restriction. Fourteen males and 13 females (body mass index: 22–26 kg/m2) participated in a crossover sleep curtailment study. Participants were studied under two sleep conditions: short (4 h/night; 0100–0500 h) and habitual (9 h/night; 2200–0700 h), for 5 nights each. Sleep was polysomnographically recorded nightly. Outcome measures included resting metabolic rate (RMR), feelings of appetite-satiety, and ad libitum food intake. Short sleep resulted in reductions in stage 2 sleep and rapid eye movement (REM) sleep duration (P < 0.001), as well as decreased percentage of stage 2 sleep and REM sleep and increased slow wave sleep (SWS) percentage (P < 0.05). Linear mixed model analysis demonstrated a positive association between stage 2 sleep duration and RMR (P = 0.051). Inverse associations were observed between REM sleep duration and hunger (P = 0.031) and between stage 2 sleep duration and appetite for sweet (P = 0.015) and salty (P = 0.046) foods. Stage 2 sleep percentage was inversely related to energy consumed (P = 0.024). Stage 2 sleep (P = 0.005), SWS (P = 0.008), and REM sleep (P = 0.048) percentages were inversely related to fat intake, and SWS (P = 0.040) and REM sleep (P = 0.050) were inversely related to carbohydrate intake. This study demonstrates that changes in sleep architecture are associated with markers of positive energy balance and indicate a means by which exposure to short sleep duration and/or an altered sleep architecture profile may lead to excess weight gain over time. PMID:22972835

  2. Spontaneous Fission

    DOE R&D Accomplishments Database

    Segre, Emilio

    1950-11-22

    The first attempt to discover spontaneous fission in uranium was made by [Willard] Libby, who, however, failed to detect it on account of the smallness of effect. In 1940, [K. A.] Petrzhak and [G. N.] Flerov, using more sensitive methods, discovered spontaneous fission in uranium and gave some rough estimates of the spontaneous fission decay constant of this substance. Subsequently, extensive experimental work on the subject has been performed by several investigators and will be quoted in the various sections. [N.] Bohr and [A.] Wheeler have given a theory of the effect based on the usual ideas of penetration of potential barriers. On this project spontaneous fission has been studied for the past several years in an effort to obtain a complete picture of the phenomenon. For this purpose the spontaneous fission decay constants {lambda} have been measured for separated isotopes of the heavy elements wherever possible. Moreover, the number {nu} of neutrons emitted per fission has been measured wherever feasible, and other characteristics of the spontaneous fission process have been studied. This report summarizes the spontaneous fission work done at Los Alamos up to January 1, 1945. A chronological record of the work is contained in the Los Alamos monthly reports.

  3. Is sleep-related verbal memory consolidation impaired in sleepwalkers?

    PubMed

    Uguccioni, Ginevra; Pallanca, Olivier; Golmard, Jean-Louis; Leu-Semenescu, Smaranda; Arnulf, Isabelle

    2015-04-01

    In order to evaluate verbal memory consolidation during sleep in subjects experiencing sleepwalking or sleep terror, 19 patients experiencing sleepwalking/sleep terror and 19 controls performed two verbal memory tasks (16-word list from the Free and Cued Selective Reminding Test, and a 220- and 263-word modified story recall test) in the evening, followed by nocturnal video polysomnography (n = 29) and morning recall (night-time consolidation after 14 h, n = 38). The following morning, they were given a daytime learning task using the modified story recall test in reverse order, followed by an evening recall test after 9 h of wakefulness (daytime consolidation, n = 38). The patients experiencing sleepwalking/sleep terror exhibited more frequent awakenings during slow-wave sleep and longer wakefulness after sleep onset than the controls. Despite this reduction in sleep quality among sleepwalking/sleep terror patients, they improved their scores on the verbal tests the morning after sleep compared with the previous evening (+16 ± 33%) equally well as the controls (+2 ± 13%). The performance of both groups worsened during the daytime in the absence of sleep (-16 ± 15% for the sleepwalking/sleep terror group and -14 ± 11% for the control group). There was no significant correlation between the rate of memory consolidation and any of the sleep measures. Seven patients experiencing sleepwalking also sleep-talked during slow-wave sleep, but their sentences were unrelated to the tests or the list of words learned during the evening. In conclusion, the alteration of slow-wave sleep during sleepwalking/sleep terror does not noticeably impact on sleep-related verbal memory consolidation. PMID:25212397

  4. Unlearning Implicit Social Biases During Sleep **

    PubMed Central

    Hu, Xiaoqing; Antony, James W.; Creery, Jessica D.; Vargas, Iliana M.; Bodenhausen, Galen V.; Paller, Ken A.

    2015-01-01

    Although people may endorse egalitarianism and tolerance, social biases can remain operative and drive harmful actions in an unconscious manner. Here we investigated training to reduce implicit racial and gender bias. Forty participants processed counter-stereotype information paired with one sound for each type of bias. Biases were reduced immediately after training. During subsequent slow-wave sleep, one sound was unobtrusively presented to each participant, repeatedly, to reactivate one type of training. Corresponding bias reductions were fortified in comparison to the social bias not externally reactivated during sleep. This advantage remained one week later, the magnitude of which was associated with time in slow-wave and rapid-eye-movement sleep after training. We conclude that memory reactivation during sleep enhances counter-stereotype training, and that maintaining a bias reduction is sleep-dependent. PMID:26023137

  5. Obstructive sleep apnea - adults

    MedlinePlus

    Sleep apnea - obstructive - adults; Apnea - obstructive sleep apnea syndrome - adults; Sleep-disordered breathing - adults; OSA - adults ... the upper airway for obstructive sleep apnea in adults. Sleep . 2010;33:1408-1413. PMID: 21061864 www. ...

  6. National Sleep Foundation

    MedlinePlus

    ... Turkish Ukrainian Urdu Vietnamese Welsh Yiddish Choose a Sleep Topic sleep.org Sleep Disorders View More Items ... Recommendations. More Join Now Become a Professional Member Sleep.org Footer Redirect Learn about how sleep impacts ...

  7. Sleep disorders - overview

    MedlinePlus

    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 ( ...

  8. About Sleep's Role in Memory

    PubMed Central

    2013-01-01

    Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of “sleep and memory” research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems. PMID:23589831

  9. Auditory Tones and Foot-Shock Recapitulate Spontaneous Sub-Threshold Activity in Basolateral Amygdala Principal Neurons and Interneurons

    PubMed Central

    Yan, Shanzhi; Stratton, Peter G.; Sullivan, Robert; Crane, James W.; Sah, Pankaj

    2016-01-01

    In quiescent states such as anesthesia and slow wave sleep, cortical networks show slow rhythmic synchronized activity. In sensory cortices this rhythmic activity shows a stereotypical pattern that is recapitulated by stimulation of the appropriate sensory modality. The amygdala receives sensory input from a variety of sources, and in anesthetized animals, neurons in the basolateral amygdala (BLA) show slow rhythmic synchronized activity. Extracellular field potential recordings show that these oscillations are synchronized with sensory cortex and the thalamus, with both the thalamus and cortex leading the BLA. Using whole-cell recording in vivo we show that the membrane potential of principal neurons spontaneously oscillates between up- and down-states. Footshock and auditory stimulation delivered during down-states evokes an up-state that fully recapitulates those occurring spontaneously. These results suggest that neurons in the BLA receive convergent input from networks of cortical neurons with slow oscillatory activity and that somatosensory and auditory stimulation can trigger activity in these same networks. PMID:27171164

  10. Astrocytic modulation of sleep homeostasis and cognitive consequences of sleep loss

    PubMed Central

    Halassa, Michael M.; Florian, Cedrick; Fellin, Tommaso; Munoz, James R.; Lee, So-Young; Abel, Ted; Haydon, Philip G.; Frank, Marcos G.

    2009-01-01

    Astrocytes modulate neuronal activity by releasing chemical transmitters via a process termed gliotransmission. The role of this process in the control of behavior is unknown. Since one outcome of SNARE-dependent gliotransmission is the regulation of extracellular adenosine and because adenosine promotes sleep, we genetically inhibited the release of gliotransmitters and asked if astrocytes play an unsuspected role in sleep regulation. Inhibiting gliotransmission attenuated the accumulation of sleep pressure, assessed by measuring the slow wave activity of the EEG during NREM sleep and prevented cognitive deficits associated with sleep loss. Since the sleep-suppressing effects of the A1 receptor antagonist CPT were prevented following inhibition of gliotransmission and because intracerebroventricular delivery of CPT to wildtype mice mimicked the transgenic phenotype we conclude that astrocytes modulate the accumulation of sleep pressure and its cognitive consequences through a pathway involving A1 receptors. PMID:19186164

  11. Electrical stimulation of the frontal cortex enhances slow-frequency EEG activity and sleepiness.

    PubMed

    D'Atri, A; De Simoni, E; Gorgoni, M; Ferrara, M; Ferlazzo, F; Rossini, P M; De Gennaro, L

    2016-06-01

    Our aim was to enhance the spontaneous slow-frequency EEG activity during the resting state using oscillating transcranial direct currents (tDCS) with a stimulation frequency that resembles the spontaneous oscillations of sleep onset. Accordingly, in this preliminary study, we assessed EEG after-effects of a frontal oscillatory tDCS with different frequency (0.8 vs. 5Hz) and polarity (anodal, cathodal, and sham). Two single-blind experiments compared the after effects on the resting EEG of oscillatory tDCS [Exp. 1=0.8Hz, 10 subjects (26.2±2.5years); Exp. 2=5Hz, 10 subjects (27.4±2.4years)] by manipulating its polarity. EEG signals recorded (28 scalp derivations) before and after stimulation [slow oscillations (0.5-1Hz), delta (1-4Hz), theta (5-7Hz), alpha (8-12Hz), beta 1 (13-15Hz) and beta 2 (16-24Hz)] were compared between conditions as a function of polarity (anodal vs. cathodal vs. sham) and frequency of stimulation (0.8 vs. 5Hz). We found a significant relative enhancement of the delta activity after the anodal tDCS at 5Hz compared to that at 0.8Hz. This increase, even though not reaching the statistical significance compared to sham, is concomitant to a significant increase of subjective sleepiness, as assessed by a visual analog scale. These two phenomena are linearly related with a regional specificity, correlations being restricted to cortical areas perifocal to the stimulation site. We have shown that a frontal oscillating anodal tDCS at 5Hz results in an effective change of both subjective sleepiness and spontaneous slow-frequency EEG activity. These changes are critically associated to both stimulation polarity (anodal) and frequency (5Hz). However, evidence of frequency-dependence seems more unequivocal than evidence of polarity-dependence. PMID:26964682

  12. Why we sleep: the evolutionary pathway to the mammalian sleep.

    PubMed

    Nicolau, M C; Akaârir, M; Gamundí, A; González, J; Rial, R V

    2000-11-01

    The cause of sleep is a complex question, which needs first, a clear distinction amongst the different meanings of a causal relationship in the study of a given behavior, second, the requisites to be met by a suggested cause, and third, a precise definition of sleep to distinguish behavioral from polygraphic sleep. This review aims at clarifying the meaning of the question and at showing the phylogenetic origin of the mammalian and avian sleep. The phylogenetic appearance of sleep can be approached through a study of the evolution of the vertebrate brain. This began as an undifferentiated dorsal nerve, which was followed by the development of an anterior simplified brain and ended with the formation of the multilayered mammalian neocortex or the avian neostriate. The successive stages in the differentiation of the vertebrate brain produced, at least, two different waking types. The oldest one is the diurnal activity, bound to the light phase of the circadian cycle. Poikilotherms control the waking from the whole brainstem, where their main sensorymotor areas lie. Mammals developed the thalamocortical lines, which displaced the waking up to the cortex after acquiring homeothermy and nocturnal lifestyle. In order to avoid competence between duplicate systems, the early waking type, controlled from the brainstem, was suppressed, and by necessity was turned into inactivity, probably slow wave sleep. On the other hand, the nocturnal rest of poikilotherms most probably resulted in rapid eye movement sleep. The complex structure of the mammalian sleep should thus be considered an evolutionary remnant; the true acquisition of mammals is the cortical waking and not the sleep. PMID:10856610

  13. Sleep and Aging

    MedlinePlus

    ... There are two types of sleep: non-rapid eye movement -- or NREM sleep -- and rapid eye movement -- or REM sleep. NREM sleep includes four stages, ranging from light to deep sleep. Then we go into REM sleep, the most active ... During REM sleep, the eyes move back and forth beneath the eyelids and ...

  14. Urodynamic function during sleep-like brain states in urethane anesthetized rats

    PubMed Central

    Crook, J.; Lovick, T.

    2016-01-01

    The aim was to investigate urodynamic parameters and functional excitability of the periaqueductal gray matter (PAG) during changes in sleep-like brain states in urethane anesthetized rats. Simultaneous recordings of detrusor pressure, external urethral sphincter (EUS) electromyogram (EMG), cortical electroencephalogram (EEG), and single-unit activity in the PAG were made during repeated voiding induced by continuous infusion of saline into the bladder. The EEG cycled between synchronized, high-amplitude slow wave activity (SWA) and desynchronized low-amplitude fast activity similar to slow wave and ‘activated’ sleep-like brain states. During (SWA, 0.5–1.5 Hz synchronized oscillation of the EEG waveform) voiding became more irregular than in the ‘activated’ brain state (2–5 Hz low-amplitude desynchronized EEG waveform) and detrusor void pressure threshold, void volume threshold and the duration of bursting activity in the external urethral sphincter EMG were raised. The spontaneous firing rate of 23/52 neurons recorded within the caudal PAG and adjacent tegmentum was linked to the EEG state, with the majority of responsive cells (92%) firing more slowly during SWA. Almost a quarter of the cells recorded (12/52) showed phasic changes in firing rate that were linked to the occurrence of voids. Inhibition (n = 6), excitation (n = 4) or excitation/inhibition (n = 2) was seen. The spontaneous firing rate of 83% of the micturition-responsive cells was sensitive to changes in EEG state. In nine of the 12 responsive cells (75%) the responses were reduced during SWA. We propose that during different sleep-like brain states changes in urodynamic properties occur which may be linked to changing excitability of the micturition circuitry in the periaqueductal gray. PMID:26601774

  15. Changes in Processing of Masked Stimuli across Early- and Late-Night Sleep: A Study on Behavior and Brain Potentials

    ERIC Educational Resources Information Center

    Verleger, Rolf; Schuknecht, Simon-Vitus; Jaskowski, Piotr; Wagner, Ullrich

    2008-01-01

    Sleep has proven to support the memory consolidation in many tasks including learning of perceptual skills. Explicit, conscious types of memory have been demonstrated to benefit particularly from slow-wave sleep (SWS), implicit, non-conscious types particularly from rapid eye movement (REM) sleep. By comparing the effects of early-night sleep,…

  16. A tryptic hydrolysate from bovine milk αs1-casein enhances pentobarbital-induced sleep in mice via the GABAA receptor.

    PubMed

    Dela Peña, Irene Joy I; Kim, Hee Jin; de la Peña, June Bryan; Kim, Mikyung; Botanas, Chrislean Jun; You, Kyung Yi; Woo, Taeseon; Lee, Yong Soo; Jung, Jae-Chul; Kim, Kyung-Mi; Cheong, Jae Hoon

    2016-10-15

    Studies have shown that enzymatic hydrolysis of casein, the primary protein component of cow's milk, produces peptides with various biological activities, and some of these peptides may have sleep-promoting effects. In the present study, we evaluated the sedative and sleep-promoting effects of bovine αS1-casein tryptic hydrolysate (CH), containing a decapeptide αS1-casein known as alpha-casozepine. CH was orally administered to ICR mice at various concentrations (75, 150, 300, or 500mg/kg). An hour after administration, assessment of its sedative (open-field and rota-rod tests) and sleep-potentiating effects (pentobarbital-induced sleeping test and EEG monitoring) were conducted. Although a trend can be observed, CH treatment did not significantly alter the spontaneous locomotor activity and motor function of mice in the open-field and rota-rod tests. On the other hand, CH (150mg/kg, respectively) enhanced the sleep induced by pentobarbital sodium in mice. It also promoted slow-wave (delta) EEG activity in rats; a pattern indicative of sleep or relaxation. These behavioral results indicate that CH has sleep-promoting effects, but no or has minimal sedative effects. To elucidate the probable mechanism behind the effects of CH, we examined its action on intracellular chloride ion influx in cultured human neuroblastoma cells. CH dose-dependently increased chloride ion influx, which was blocked by co-administration of bicuculline, a competitive GABAA receptor antagonist. Taken together, the results of the present study suggest that CH has sleep-promoting properties which are probably mediated through the GABAA receptor-chloride ion channel complex. PMID:27401107

  17. Cognitive Workload and Sleep Restriction Interact to Influence Sleep Homeostatic Responses

    PubMed Central

    Goel, Namni; Abe, Takashi; Braun, Marcia E.; Dinges, David F.

    2014-01-01

    Study Objectives: Determine the effects of high versus moderate workload on sleep physiology and neurobehavioral measures, during sleep restriction (SR) and no sleep restriction (NSR) conditions. Design: Ten-night experiment involving cognitive workload and SR manipulations. Setting: Controlled laboratory environment. Participants: Sixty-three healthy adults (mean ± standard deviation: 33.2 ± 8.7 y; 29 females), age 22–50 y. Interventions: Following three baseline 8 h time in bed (TIB) nights, subjects were randomized to one of four conditions: high cognitive workload (HW) + SR; moderate cognitive workload (MW) + SR; HW + NSR; or MW + NSR. SR entailed 5 consecutive nights at 4 h TIB; NSR entailed 5 consecutive nights at 8 h TIB. Subjects received three workload test sessions/day consisting of 15-min preworkload assessments, followed by a 60-min (MW) or 120-min (HW) workload manipulation comprised of visually based cognitive tasks, and concluding with 15-min of postworkload assessments. Experimental nights were followed by two 8-h TIB recovery sleep nights. Polysomnography was collected on baseline night 3, experimental nights 1, 4, and 5, and recovery night 1 using three channels (central, frontal, occipital [C3, Fz, O2]). Measurements and Results: High workload, regardless of sleep duration, increased subjective fatigue and sleepiness (all P < 0.05). In contrast, sleep restriction produced cumulative increases in Psychomotor Vigilance Test (PVT) lapses, fatigue, and sleepiness and decreases in PVT response speed and Maintenance of Wakefulness Test (MWT) sleep onset latencies (all P < 0.05). High workload produced longer sleep onset latencies (P < 0.05, d = 0.63) and less wake after sleep onset (P < 0.05, d = 0.64) than moderate workload. Slow-wave energy—the putative marker of sleep homeostasis—was higher at O2 than C3 only in the HW + SR condition (P < 0.05). Conclusions: High cognitive workload delayed sleep onset, but it also promoted sleep homeostatic

  18. Postoperative sleep disruptions: a potential catalyst of acute pain?

    PubMed

    Chouchou, Florian; Khoury, Samar; Chauny, Jean-Marc; Denis, Ronald; Lavigne, Gilles J

    2014-06-01

    Despite the substantial advances in the understanding of pain mechanisms and management, postoperative pain relief remains an important health care issue. Surgical patients also frequently report postoperative sleep complaints. Major sleep alterations in the postoperative period include sleep fragmentation, reduced total sleep time, and loss of time spent in slow wave and rapid eye movement sleep. Clinical and experimental studies show that sleep disturbances may exacerbate pain, whereas pain and opioid treatments disturb sleep. Surgical stress appears to be a major contributor to both sleep disruptions and altered pain perception. However, pain and the use of opioid analgesics could worsen sleep alterations, whereas sleep disruptions may contribute to intensify pain. Nevertheless, little is known about the relationship between postoperative sleep and pain. Although the sleep-pain interaction has been addressed from both ends, this review focuses on the impact of sleep disruptions on pain perception. A better understanding of the effect of postoperative sleep disruptions on pain perception would help in selecting patients at risk for more severe pain and may facilitate the development of more effective and safer pain management programs. PMID:24074687

  19. Sleep dynamics: A self-organized critical system

    NASA Astrophysics Data System (ADS)

    Comte, J. C.; Ravassard, P.; Salin, P. A.

    2006-05-01

    In psychiatric and neurological diseases, sleep is often perturbed. Moreover, recent works on humans and animals tend to show that sleep plays a strong role in memory processes. Reciprocally, sleep dynamics following a learning task is modified [Hubert , Nature (London) 02663, 1 (2004), Peigneux , Neuron 44, 535 (2004)]. However, sleep analysis in humans and animals is often limited to the total sleep and wake duration quantification. These two parameters are not fully able to characterize the sleep dynamics. In mammals sleep presents a complex organization with an alternation of slow wave sleep (SWS) and paradoxical sleep (PS) episodes. Moreover, it has been shown recently that these sleep episodes are frequently interrupted by micro-arousal (without awakening). We present here a detailed analysis of the basal sleep properties emerging from the mechanisms underlying the vigilance states alternation in an animal model. These properties present a self-organized critical system signature and reveal the existence of two W, two SWS, and a PS structure exhibiting a criticality as met in sand piles. We propose a theoretical model of the sleep dynamics based on several interacting neuronal populations. This new model of sleep dynamics presents the same properties as experimentally observed, and explains the variability of the collected data. This experimental and theoretical study suggests that sleep dynamics shares several common features with critical systems.

  20. Exploring the spectrum of dynamical regimes and timescales in spontaneous cortical activity.

    PubMed

    Mattia, Maurizio; Sanchez-Vives, Maria V

    2012-06-01

    Rhythms at slow (<1 Hz) frequency of alternating Up and Down states occur during slow-wave sleep states, under deep anaesthesia and in cortical slices of mammals maintained in vitro. Such spontaneous oscillations result from the interplay between network reverberations nonlinearly sustained by a strong synaptic coupling and a fatigue mechanism inhibiting the neurons firing in an activity-dependent manner. Varying pharmacologically the excitability level of brain slices we exploit the network dynamics underlying slow rhythms, uncovering an intrinsic anticorrelation between Up and Down state durations. Besides, a non-monotonic change of Down state duration is also observed, which shrinks the distribution of the accessible frequencies of the slow rhythms. Attractor dynamics with activity-dependent self-inhibition predicts a similar trend even when the system excitability is reduced, because of a stability loss of Up and Down states. Hence, such cortical rhythms tend to display a maximal size of the distribution of Up/Down frequencies, envisaging the location of the system dynamics on a critical boundary of the parameter space. This would be an optimal solution for the system in order to display a wide spectrum of dynamical regimes and timescales. PMID:23730355

  1. Peritonitis - spontaneous

    MedlinePlus

    ... a catheter used in peritoneal dialysis. Antibiotics may control infection in cases of spontaneous peritonitis with liver or kidney disease. Intravenous therapy can treat dehydration . You may need to stay in the hospital so health care providers can rule out conditions ...

  2. Troubled sleep

    PubMed Central

    Haig, David

    2014-01-01

    Disrupted sleep is probably the most common complaint of parents with a new baby. Night waking increases in the second half of the first year of infant life and is more pronounced for breastfed infants. Sleep-related phenotypes of infants with Prader-Willi and Angelman syndromes suggest that imprinted genes of paternal origin promote greater wakefulness whereas imprinted genes of maternal origin favor more consolidated sleep. All these observations are consistent with a hypothesis that waking at night to suckle is an adaptation of infants to extend their mothers’ lactational amenorrhea, thus delaying the birth of a younger sib and enhancing infant survival. PMID:24610432

  3. Slow breathing influences cardiac autonomic responses to postural maneuver: Slow breathing and HRV.

    PubMed

    Vidigal, Giovanna Ana de Paula; Tavares, Bruna S; Garner, David M; Porto, Andrey A; Carlos de Abreu, Luiz; Ferreira, Celso; Valenti, Vitor E

    2016-05-01

    Chronic slow breathing has been reported to improve Heart Rate Variability (HRV) in patients with cardiovascular disorders. However, it is not clear regarding its acute effects on HRV responses on autonomic analysis. We evaluated the acute effects of slow breathing on cardiac autonomic responses to postural change manoeuvre (PCM). The study was conducted on 21 healthy male students aged between 18 and 35 years old. In the control protocol, the volunteer remained at rest seated for 15 min under spontaneous breathing and quickly stood up within 3 s and remained standing for 15 min. In the slow breathing protocol, the volunteer remained at rest seated for 10 min under spontaneous breath, then performed slow breathing for 5 min and rapidly stood up within 3 s and remained standing for 15 min. Slow breathing intensified cardiac autonomic responses to postural maneuver. PMID:27157952

  4. [Prevention and treatment of sleep disorders through regulation] of sleeping habits].

    PubMed

    Onen, S H; Onen, F; Bailly, D; Parquet, P

    1994-03-12

    Healthy sleeping habits is a complex balance between behaviour, environment and circadian rhythm. The quality of sleep can be improved by behaviour, e.g. eating tryptophan and carbohydrate rich foods, physical exercise in the afternoon or a cold shower just before going to bed. Total sleep time is maximal in thermoneutrality and decreases above and below the thermoneutrality zone. Thermoneutrality is reached for an environmental temperature of 30-32 degrees C without night clothing or of 16-19 degrees with a pyjama and at least one sheet. Noise also modifies sleep structure and above 50dB shortens total sleeping time. Although subjects do become subjectively accustomed to noise, vegetative cardiovascular reactivity to environmental noise remains unchanged. The spontaneous circadian awake/sleep cycle is 25 hours, slightly longer than the body temperature cycle, but when subjects are exposed to environmental synchronization, the two cycles coincide. In individuals undergoing temporal isolation, the two rhythms become independent often leading to subjective discomfort and fatigue. Certain factors including age can favour internal desynchronization. Other factors may include social contact, stress due to mental work load, and constant lighting which could lengthen the awake/sleep cycle. Caffeine blocks the receptors of adenosine, and thus its effects of inhibiting neurotransmission. Intake 30 to 60 minutes before sleeping shortens total sleep time and increases the duration of stage 2 and shortens stage 3 and 4. Alcohol may act as a relaxing, sedative agent when consumed just before sleeping but can also lead to night-time awakening due to sympathetic activation which does not return to baseline levels until the blood alcohol levels have returned to 0. Nicotine has a biphasic effect on sleep: at low concentrations, it leads to relaxation and sedation and at high concentrations inhibits sleep. A careful study of sleeping habits is the first step in evaluating complains

  5. Synaptic plasticity modulates autonomous transitions between waking and sleep states: Insights from a Morris-Lecar model

    NASA Astrophysics Data System (ADS)

    Ciszak, Marzena; Bellesi, Michele

    2011-12-01

    The transitions between waking and sleep states are characterized by considerable changes in neuronal firing. During waking, neurons fire tonically at irregular intervals and a desynchronized activity is observed at the electroencephalogram. This activity becomes synchronized with slow wave sleep onset when neurons start to oscillate between periods of firing (up-states) and periods of silence (down-states). Recently, it has been proposed that the connections between neurons undergo potentiation during waking, whereas they weaken during slow wave sleep. Here, we propose a dynamical model to describe basic features of the autonomous transitions between such states. We consider a network of coupled neurons in which the strength of the interactions is modulated by synaptic long term potentiation and depression, according to the spike time-dependent plasticity rule (STDP). The model shows that the enhancement of synaptic strength between neurons occurring in waking increases the propensity of the network to synchronize and, conversely, desynchronization appears when the strength of the connections become weaker. Both transitions appear spontaneously, but the transition from sleep to waking required a slight modification of the STDP rule with the introduction of a mechanism which becomes active during sleep and changes the proportion between potentiation and depression in accordance with biological data. At the neuron level, transitions from desynchronization to synchronization and vice versa can be described as a bifurcation between two different states, whose dynamical regime is modulated by synaptic strengths, thus suggesting that transition from a state to an another can be determined by quantitative differences between potentiation and depression.

  6. [Night sleep patterns in post-operative intensive care patients (author's transl)].

    PubMed

    Landau-Ferey, J; Rebelo, F; Glaser, P; Garma, L

    1977-01-01

    5 patients admitted to intensive care following post-operative complications had EEG recordings on 2 consecutive nights some time after their operations. Study of the different sleep stages showed a marked increase in deep slow wave sleep and waking but asignificant reduction in light slow wave sleep and paradoxical sleep. The appearance of the sleep cycles through the night was unusual with respect to the maximum occurrence of the various stages and their evolution. Finally certain characteristics of paradoxical sleep, the rhythm and duration of the phases and the number and frequency of ocular movements were also modified. Comparison of these findings with those previously reported show that these abnormalities, rather than suggesting sleep deprivation resemble more closely the fidings in shift workers when they resume night sleep after a period of day sleep. The also resemble the changes seen in people whose circadian rhythm has been displaced by 12 hours. PMID:565525

  7. Exercise & Sleep

    MedlinePlus

    ... on. Feature: Back to School, the Healthy Way Exercise & Sleep Past Issues / Fall 2012 Table of Contents ... helps kids. Photo: iStock 6 "Bests" About Kids' Exercise At least one hour of physical activity a ...

  8. Sleeping sickness

    MedlinePlus

    Human African trypanosomiasis ... Kirchoff LV. Agents of African trypanosomiasis (sleeping sickness). In: Mandell GL, Bennett JE, Dolan R, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases . 8th ...

  9. American Sleep Association

    MedlinePlus

    ... of sleep. Why we sleep. Why do we dream? Sleep Hygiene Tips Get good sleep now. What ... Forum Posts 90 minute rule. _ Re: Insomnia question _ Artificial foods acting as stimulant and causing insomnia _ DNP ...

  10. Pediatric sleep apnea

    MedlinePlus

    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 ...

  11. Obstructive sleep apnea - adults

    MedlinePlus

    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 ...

  12. Isolated sleep paralysis

    MedlinePlus

    ... from sleep. It is not associated with another sleep disorder. ... Sleep paralysis can be a symptom of narcolepsy . But if you do not have other symptoms of narcolepsy, there is usually no need to have sleep studies done.

  13. Brain Basics: Understanding Sleep

    MedlinePlus

    ... Many of the body's cells also show increased production and reduced breakdown of proteins during deep sleep. ... deep sleep, REM sleep is associated with increased production of proteins. One study found that REM sleep ...

  14. Snoring and Sleep Apnea

    MedlinePlus

    ... Find an ENT Doctor Near You Snoring and Sleep Apnea Snoring and Sleep Apnea Patient Health Information ... newsroom@entnet.org . Insight into sleeping disorders and sleep apnea Forty-five percent of normal adults snore ...

  15. Isolated sleep paralysis

    MedlinePlus

    ... from sleep. It is not associated with another sleep disorder. Symptoms Episodes of isolated sleep paralysis last from ... A.M. Editorial team. Related MedlinePlus Health Topics Sleep Disorders Browse the Encyclopedia A.D.A.M., Inc. ...

  16. American Sleep Apnea Association

    MedlinePlus

    American Sleep Apnea Association Learn About the CPAP Assistance Program About ASAA News about ASAA Who we are Leadership Team Supporting the ASAA Financials Learn Healthy sleep Sleep apnea Other sleep disorders Personal stories Treat Test Yourself ...

  17. Refreshing Sleep and Sleep Continuity Determine Perceived Sleep Quality.

    PubMed

    Libman, Eva; Fichten, Catherine; Creti, Laura; Conrod, Kerry; Tran, Dieu-Ly; Grad, Roland; Jorgensen, Mary; Amsel, Rhonda; Rizzo, Dorrie; Baltzan, Marc; Pavilanis, Alan; Bailes, Sally

    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 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. PMID:27413553

  18. Refreshing Sleep and Sleep Continuity Determine Perceived Sleep Quality

    PubMed Central

    Fichten, Catherine; Creti, Laura; Conrod, Kerry; Tran, Dieu-Ly; Grad, Roland; Jorgensen, Mary; Amsel, Rhonda; Rizzo, Dorrie; Baltzan, Marc; Pavilanis, Alan; Bailes, Sally

    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 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. PMID:27413553

  19. Electroencephalographic studies of sleep

    NASA Technical Reports Server (NTRS)

    Webb, W. B.; Agnew, H. W., Jr.

    1975-01-01

    Various experimental studies on sleep are described. The following areas are discussed: (1) effect of altered day length on sleep, (2) effect of a partial loss of sleep on subsequent nocturnal sleep; (3) effect of rigid control over sleep-wake-up times; (4) sleep and wakefulness in a time-free environment; (5) distribution of spindles during a full night of sleep; and (6) effect on sleep and performance of swiftly changing shifts of work.

  20. Slow Pseudotachylites

    NASA Astrophysics Data System (ADS)

    Pec, M.; Stunitz, H.; Heilbronner, R.

    2011-12-01

    Tectonic pseudotachylites as solidified, friction induced melts are believed to be the only unequivocal evidence for paleo-earthquakes. Earthquakes occur when fast slip (1 - 3 m/s) propagates on a localized failure plane and are always related with stress drops. The mechanical work expended, together with the rock composition and the efficiency of thermal dissipation, controls whether the temperature increase on a localized slip plane will be sufficient to induce fusion. We report the formation of pseudotachylites during steady-state plastic flow at slow bulk shear strain rates (~10^-3 to ~10^-5 /s corresponding to slip rates of ~10^-6 to ~10^-8 m/s) in experiments performed at high confining pressures (500 MPa) and temperatures (300°C) corresponding to a depth of ~15 km. Crushed granitioid rock (Verzasca gneiss), grain size ≤ 200 μm, with 0.2 wt% water added was placed between alumina forcing blocks pre-cut at 45°, weld-sealed in platinum jackets and deformed with a constant displacement rate in a solid medium deformation apparatus (modified Griggs rig). Microstructural observations show the development of a S-C-C' fabric with C' slip zones being the dominant feature. Strain hardening in the beginning of the experiment is accompanied with compaction which is achieved by closely spaced R1 shears pervasively cutting the whole gouge zone and containing fine-grained material (d < 100 nm). The peak strength is achieved at γ ~ 2 at shear stress levels of 1350-1450 MPa when compaction ceases. During further deformation, large local displacements (γ > 10) are localized in less densely spaced, ~10 μm thick C'-C slip zones which develop predominantly in feldspars and often contain micas. In TEM, they appear to have no porosity consisting of partly amorphous material and small crystalline fragments with the average grain size of 20 nm. After the peak strength, the samples weaken by ~20 MPa and continue deforming up to γ ~ 4 without any stress drops. Strain

  1. Sleep and Learning

    NASA Astrophysics Data System (ADS)

    Margoliash, Daniel

    2010-03-01

    The neural basis of cognition represents a grand challenge problem involving multiple disciplines and approaches to the analysis of behavior. Song learning by juvenile songbirds such as zebra finches has proven to have considerable utility for exploring how behavior is represented at multiple levels of brain function. As classically described, young birds are exposed to a ``tutor'' (adult) song and commit that song to memory early in life, then engage in an extended period (weeks) of plastic singing as they slowly learn to match vocal output to the tutor song memory via auditory feedback. In recent years, the role of sleep in learning processes has been actively explored. Young birds isolated from adult songs, then suddenly given access to such songs at circa 40 days of age, show a sudden change in their singing behavior starting on the day following first exposure. Such birds sing songs that have less structure in the mornings than do the songs sung in the afternoons before or after that morning. This fluctuation is directly the result of sleep (not circadian rhythm), and the magnitude of fluctuation is positively correlated with the ultimate similarity to the tutor song. Examining spontaneous neuronal activity in certain brain structures during the night in sleeping adults shows ``replay'' of the patterns of activity the same neurons exhibit during daytime singing, and ``preplay'' of new patterns that will first be incorporated into daytime singing the following day. In experiments on juveniles, nighttime neuronal activity shows dramatic changes associated with song learning, even on the night after the first day of tutor song exposure (preceding changes in singing behavior). Offline processing, especially sleep, has been well documented to participate in memory consolidation in a very broad range of behaviors including in humans. Placing the bird song results in a theoretical framework thereby helps to inform a very broad range of phenomena.

  2. Physiological consequences of selective suppression of synaptic transmission in developing cerebral cortical networks in vitro: differential effects on intrinsically generated bioelectric discharges in a living 'model' system for slow-wave sleep activity.

    PubMed

    Corner, Michael A; Baker, Robert E; van Pelt, Jaap

    2008-10-01

    Within the context of an updated thorough review of the literature concerning activity-dependent cerebro-cortical development, a survey is made of recent experiments which utilize spontaneous spike-trains as the dependent variable in rodent neocortex cultures when synaptic transmission is interfered with during early ontogeny. Emphasis is placed on the complexity of homeostatic adaptations to reduced as well as intensified firing. Two kinds of adaptation are distinguished: (i) rapid recovery (within several hours) towards baseline levels despite sustained blockade of excitatory synaptic transmission, and (ii) the generation of essentially normal firing patterns in cultures assayed in control medium following development in the presence of excitatory receptor blockers. The former category of homeostatic responses is strongly dependent on the type of preparation, with isolated organotypic explants showing greatly limited plasticity in comparison with co-cultures of matching contralateral pieces of cortical tissue. In such co-cultures, compensatory excitatory drive manifests itself even when all three known types of ionotropic glutamate receptors are chronically blocked, and is then mediated by (muscarinic) cholinergic mechanisms which normally do not contribute measurably to spontaneous activity. The rapid return of high levels of spontaneous firing during sustained selective glutamatergic receptor blockade appears to protect neuronal cultures treated in this way from becoming hyperexcitable. In particular, quasi-epileptiform paroxysmal bursting upon return to control medium, such as appears in preparations where bioelectric activity has been totally suppressed during network formation, fails to appear in chronically receptor blocked cultures. On the contrary, desensitization of blocked glutamate receptors, as a physiological compensation for the up-regulation of non-blocked receptors, could be demonstrated for both the AMPA and the NMDA glutamate receptor sub

  3. A new function of rapid eye movement sleep: improvement of muscular efficiency.

    PubMed

    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. PMID:25770701

  4. Intragastric administration of glutamate increases REM sleep in rats.

    PubMed

    Datta, Karuna; Kumar, Deependra; Mallick, Hruda Nanda

    2013-10-01

    Monosodium glutamate, a umami taste substance is commonly used flavor enhancer. The effect of intragastric administration of 1.5 ml of 0.12M monosodium glutamate on sleep-wake was studied in 10 adult male Wistar rats. Sleep-wake parameters were recorded through chronically implanted electroencephalogram, electrooculogram and electromyogram electrodes using a digital recording system (BIOPAC system Inc. BSL PRO 36, USA). The sleep-wake was recorded for 6h after the intragastric administration of either glutamate or saline. Sleep-wake stages were analyzed as wake, slow wave sleep and REM sleep. Compared to saline, intragastric administration of glutamate significantly increased REM sleep duration and episode frequency. REM sleep duration was increased in all the three 2h bins, 10:00-12:00 h (p=0.037), 12:00-14:00 h (p=0.037) and 14:00-16:00 h (p=0.007). The slow wave sleep and total sleep time were not affected. It is concluded that intragastric glutamate administration increases REM sleep. PMID:24055576

  5. Initiation of sleep-dependent cortical-hippocampal correlations at wakefulness-sleep transition.

    PubMed

    Haggerty, Daniel C; Ji, Daoyun

    2014-10-01

    Sleep is involved in memory consolidation. Current theories propose that sleep-dependent memory consolidation requires active communication between the hippocampus and neocortex. Indeed, it is known that neuronal activities in the hippocampus and various neocortical areas are correlated during slow-wave sleep. However, transitioning from wakefulness to slow-wave sleep is a gradual process. How the hippocampal-cortical correlation is established during the wakefulness-sleep transition is unknown. By examining local field potentials and multiunit activities in the rat hippocampus and visual cortex, we show that the wakefulness-sleep transition is characterized by sharp-wave ripple events in the hippocampus and high-voltage spike-wave events in the cortex, both of which are accompanied by highly synchronized multiunit activities in the corresponding area. Hippocampal ripple events occur earlier than the cortical high-voltage spike-wave events, and hippocampal ripple incidence is attenuated by the onset of cortical high-voltage spike waves. This attenuation leads to a temporary weak correlation in the hippocampal-cortical multiunit activities, which eventually evolves to a strong correlation as the brain enters slow-wave sleep. The results suggest that the hippocampal-cortical correlation is established through a concerted, two-step state change that first synchronizes the neuronal firing within each brain area and then couples the synchronized activities between the two regions. PMID:25008411

  6. Initiation of sleep-dependent cortical-hippocampal correlations at wakefulness-sleep transition

    PubMed Central

    Haggerty, Daniel C.

    2014-01-01

    Sleep is involved in memory consolidation. Current theories propose that sleep-dependent memory consolidation requires active communication between the hippocampus and neocortex. Indeed, it is known that neuronal activities in the hippocampus and various neocortical areas are correlated during slow-wave sleep. However, transitioning from wakefulness to slow-wave sleep is a gradual process. How the hippocampal-cortical correlation is established during the wakefulness-sleep transition is unknown. By examining local field potentials and multiunit activities in the rat hippocampus and visual cortex, we show that the wakefulness-sleep transition is characterized by sharp-wave ripple events in the hippocampus and high-voltage spike-wave events in the cortex, both of which are accompanied by highly synchronized multiunit activities in the corresponding area. Hippocampal ripple events occur earlier than the cortical high-voltage spike-wave events, and hippocampal ripple incidence is attenuated by the onset of cortical high-voltage spike waves. This attenuation leads to a temporary weak correlation in the hippocampal-cortical multiunit activities, which eventually evolves to a strong correlation as the brain enters slow-wave sleep. The results suggest that the hippocampal-cortical correlation is established through a concerted, two-step state change that first synchronizes the neuronal firing within each brain area and then couples the synchronized activities between the two regions. PMID:25008411

  7. Polysomnographic study of nocturnal sleep in idiopathic hypersomnia without long sleep time.

    PubMed

    Pizza, Fabio; Ferri, Raffaele; Poli, Francesca; Vandi, Stefano; Cosentino, Filomena I I; Plazzi, Giuseppe

    2013-04-01

    We investigated nocturnal sleep abnormalities in 19 patients with idiopathic hypersomnia without long sleep time (IH) in comparison with two age- and sex- matched control groups of 13 normal subjects (C) and of 17 patients with narcolepsy with cataplexy (NC), the latter considered as the extreme of excessive daytime sleepiness (EDS). Sleep macro- and micro- (i.e. cyclic alternating pattern, CAP) structure as well as quantitative analysis of EEG, of periodic leg movements during sleep (PLMS), and of muscle tone during REM sleep were compared across groups. IH and NC patients slept more than C subjects, but IH showed the highest levels of sleep fragmentation (e.g. awakenings), associated with a CAP rate higher than NC during lighter sleep stages and lower than C during slow wave sleep respectively, and with the highest relative amount of A3 and the lowest of A1 subtypes. IH showed a delta power in between C and NC groups, whereas muscle tone and PLMS had normal characteristics. A peculiar profile of microstructural sleep abnormalities may contribute to sleep fragmentation and, possibly, EDS in IH. PMID:23061443

  8. Disturbed dreaming and sleep quality: altered sleep architecture in subjects with frequent nightmares.

    PubMed

    Simor, Péter; Horváth, Klára; Gombos, Ferenc; Takács, Krisztina P; Bódizs, Róbert

    2012-12-01

    Nightmares are intense, emotionally negative mental experiences that usually occur during late-night sleep and result in abrupt awakenings. Questionnaire-based studies have shown that nightmares are related to impaired sleep quality; however, the polysomnographic profile of nightmare subjects has been only scarcely investigated. We investigated the sleep architecture of 17 individuals with frequent nightmares and 23 control subjects based on polysomnographic recordings of a second night spent in the laboratory after an adaptation night. Nightmare subjects in comparison with control subjects were characterized by impaired sleep architecture, as reflected by reduced sleep efficiency, increased wakefulness, a reduced amount of slow wave sleep, and increased nocturnal awakenings, especially from Stage 2 sleep. While these differences were independent of the effects of waking psychopathology, nightmare subjects also exhibited longer durations of REM sleep that was mediated by heightened negative affect. Our results support that nightmares are related to altered sleep architecture, showing impaired sleep continuity and emotion-related increase in REM propensity. PMID:22526731

  9. Symposium: Cognitive processes and sleep disturbances: Sleep, dreams and memory: an overview.

    PubMed

    Cipolli

    1995-03-01

    Investigations into the role played by sleep in information processing have consistently shown that the retention of information is better when the memory storage is followed by a period of sleep than of waking. Less definitive evidence, however, is available as to whether the better performance is mainly due to (a) reduction of interference during sleep, (b) slowing down of decay, or (c) consolidation processes at work during sleep. Important insights as to whether consolidation takes place during sleep have recently been provided by the thematic continuity of dreams elaborated in the same night and by the repeated incorporation of pre-sleep stimuli into dream contents. The analysis of such aspects of dreaming indicates that the items of information which are repeatedly accessed during sleep and elaborated for insertion into the ongoing dream experience are better retained at delayed recall. Finally, it is suggested that the use of the strategies applied in studying the information processing in normals may also be extended to sleep-disturbed individuals, in order to establish how memory functioning during sleep is influenced by sleep disturbances. PMID:10607134

  10. Paradoxical (rapid eye movement) sleep-on neurons in the laterodorsal pontine tegmentum in mice.

    PubMed

    Sakai, K

    2015-12-01

    A total of 211 neurons that discharged at the highest rate during sleep (sleep-active neurons) were recorded in non-anesthetized, head-restrained mice during the complete wake-sleep cycle in, and around, the laterodorsal (LDT) and sublaterodorsal (SubLDT) tegmental nuclei, which contain both cholinergic and non-cholinergic neurons. For the first time in mice, I reveal the presence, mainly in the SubLDT, of sleep-specific neurons displaying sustained tonic discharge either (i) just prior to, and during, paradoxical sleep (PS) (PS-on neurons) or (ii) during both slow-wave sleep (SWS) and PS (SWS/PS-on neurons). Both the PS-on and SWS/PS-on neurons showed either a low (< 10 Hz) or high (⩾ 10 Hz) rate of spontaneous firing and exhibited a biphasic narrow or medium-to-broad action potential, a characteristic of non-cholinergic neurons. At the transition from SWS to waking (W), the PS-on and SWS/PS-on neurons simultaneously ceased firing shortly before the onset of W, whereas, at the transition from W to SWS, only the SWS/PS-on neurons fired shortly after the onset of sleep. At the transition from SWS to PS, only the PS-on neurons exhibited a significant increase in discharge rate before PS onset, while, at the transition from PS to W, the SWS/PS-on neurons, then the PS-on neurons, displayed a significant decrease in the discharge rate before the end of PS. The SWS/PS-on neurons were more sensitive to the change in the electroencephalogram (EEG) than the PS-on neurons, as, during a PS episode, the slightest interruption of rhythmic theta activity resulted in cessation of discharge of the SWS/PS-on neurons. These findings support the view that, in the mouse SubLDT, PS-on neurons play an important role in the induction, maintenance, and cessation of PS, while SWS/PS-on neurons play a role in the maintenance of the PS state in particular and the sleep state in general. PMID:26424378