scholarly journals Lempel-Ziv complexity of cortical activity during sleep and waking in rats

2015 ◽  
Vol 113 (7) ◽  
pp. 2742-2752 ◽  
Author(s):  
Daniel Abásolo ◽  
Samantha Simons ◽  
Rita Morgado da Silva ◽  
Giulio Tononi ◽  
Vladyslav V. Vyazovskiy
Keyword(s):  
Sleep Deprivation ◽  
Eye Movement ◽  
Brain Activity ◽  
Temporal Structure ◽  
Nrem Sleep ◽  
Brain State ◽  
Rapid Eye Movement ◽  
Sleep Regulation ◽  
Spatio Temporal ◽  
Underlying Mechanisms

Understanding the dynamics of brain activity manifested in the EEG, local field potentials (LFP), and neuronal spiking is essential for explaining their underlying mechanisms and physiological significance. Much has been learned about sleep regulation using conventional EEG power spectrum, coherence, and period-amplitude analyses, which focus primarily on frequency and amplitude characteristics of the signals and on their spatio-temporal synchronicity. However, little is known about the effects of ongoing brain state or preceding sleep-wake history on the nonlinear dynamics of brain activity. Recent advances in developing novel mathematical approaches for investigating temporal structure of brain activity based on such measures, as Lempel-Ziv complexity (LZC) can provide insights that go beyond those obtained with conventional techniques of signal analysis. Here, we used extensive data sets obtained in spontaneously awake and sleeping adult male laboratory rats, as well as during and after sleep deprivation, to perform a detailed analysis of cortical LFP and neuronal activity with LZC approach. We found that activated brain states—waking and rapid eye movement (REM) sleep are characterized by higher LZC compared with non-rapid eye movement (NREM) sleep. Notably, LZC values derived from the LFP were especially low during early NREM sleep after sleep deprivation and toward the middle of individual NREM sleep episodes. We conclude that LZC is an important and yet largely unexplored measure with a high potential for investigating neurophysiological mechanisms of brain activity in health and disease.

scholarly journals Global field synchronization reveals rapid eye movement sleep as most synchronized brain state in the human EEG

2016 ◽  
Vol 3 (10) ◽  
pp. 160201 ◽  
Author(s):  
Peter Achermann ◽  
Thomas Rusterholz ◽  
Roland Dürr ◽  
Thomas König ◽  
Leila Tarokh
Keyword(s):  
Functional Connectivity ◽  
Sleep Deprivation ◽  
Eye Movement ◽  
Rem Sleep ◽  
Nrem Sleep ◽  
Brain Regions ◽  
Global Field ◽  
Brain State ◽  
Rapid Eye Movement ◽  
Eyes Closed

Sleep is characterized by a loss of consciousness, which has been attributed to a breakdown of functional connectivity between brain regions. Global field synchronization (GFS) can estimate functional connectivity of brain processes. GFS is a frequency-dependent measure of global synchronicity of multi-channel EEG data. Our aim was to explore and extend the hypothesis of disconnection during sleep by comparing GFS spectra of different vigilance states. The analysis was performed on eight healthy adult male subjects. EEG was recorded during a baseline night, a recovery night after 40 h of sustained wakefulness and at 3 h intervals during the 40 h of wakefulness. Compared to non-rapid eye movement (NREM) sleep, REM sleep showed larger GFS values in all frequencies except in the spindle and theta bands, where NREM sleep showed a peak in GFS. Sleep deprivation did not affect GFS spectra in REM and NREM sleep. Waking GFS values were lower compared with REM and NREM sleep except for the alpha band. Waking alpha GFS decreased following sleep deprivation in the eyes closed condition only. Our surprising finding of higher synchrony during REM sleep challenges the view of REM sleep as a desynchronized brain state and may provide insight into the function of REM sleep.

Anti-interleukin-1 beta reduces sleep and sleep rebound after sleep deprivation in rats

1994 ◽  
Vol 266 (3) ◽  
pp. R688-R695 ◽  
Author(s):  
M. R. Opp ◽  
J. M. Krueger
Keyword(s):  
Sleep Deprivation ◽  
Eye Movement ◽  
Interleukin 1 ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Sleep Regulation ◽  
Light Onset ◽  
Deprivation Period ◽  
Additional Support ◽  
Physiological Sleep

Interleukin-1 (IL-1) is somnogenic and is hypothesized to be involved in physiological sleep regulation. Antibodies directed against rat IL-1 beta were used to further elucidate possible contributions of IL-1 to sleep regulation. Rabbit anti-rat IL-1 beta (anti-IL-1 beta) was injected intracerebroventricularly into normal rats 15 min before light onset. A 20-microgram dose of anti-IL-1 beta reduced non-rapid-eye-movement (NREM) sleep by 60 min during the subsequent 12-h slight period. There was no effect on rapid eye movement sleep after this dose of anti-IL-1 beta. The effects of anti-IL-1 beta on the enhancement of sleep after periods of sleep deprivation were also determined. When rats were deprived of sleep for 3-h beginning at light onset, the amount of time spent in NREM sleep increased for the remaining 9 h of the light period, regardless of whether control intracerebroventricular injections of pyrogen-free saline or rabbit immunoglobulin G were given during the deprivation period. However, when 20 micrograms anti-IL-1 beta were injected intracerebroventricularly during the sleep deprivation period, the expected NREM sleep rebound was completely blocked. Collectively, these data provide additional support for the hypothesis that IL-1 is involved in regulation of physiological sleep-wake activity.

scholarly journals The European starling (Sturnus vulgaris) shows signs of NREM sleep homeostasis but has very little REM sleep and no REM sleep homeostasis

SLEEP ◽  
2019 ◽  
Vol 43 (6) ◽  
Author(s):  
Sjoerd J van Hasselt ◽  
Maria Rusche ◽  
Alexei L Vyssotski ◽  
Simon Verhulst ◽  
Niels C Rattenborg ◽  
...  
Keyword(s):  
Sleep Deprivation ◽  
Eye Movement ◽  
Rem Sleep ◽  
Spectral Power ◽  
Nrem Sleep ◽  
Sleep Time ◽  
European Starling ◽  
Dark Phase ◽  
Rapid Eye Movement ◽  
Sleep Homeostasis

Abstract Most of our knowledge about the regulation and function of sleep is based on studies in a restricted number of mammalian species, particularly nocturnal rodents. Hence, there is still much to learn from comparative studies in other species. Birds are interesting because they appear to share key aspects of sleep with mammals, including the presence of two different forms of sleep, i.e. non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. We examined sleep architecture and sleep homeostasis in the European starling, using miniature dataloggers for electroencephalogram (EEG) recordings. Under controlled laboratory conditions with a 12:12 h light–dark cycle, the birds displayed a pronounced daily rhythm in sleep and wakefulness with most sleep occurring during the dark phase. Sleep mainly consisted of NREM sleep. In fact, the amount of REM sleep added up to only 1~2% of total sleep time. Animals were subjected to 4 or 8 h sleep deprivation to assess sleep homeostatic responses. Sleep deprivation induced changes in subsequent NREM sleep EEG spectral qualities for several hours, with increased spectral power from 1.17 Hz up to at least 25 Hz. In contrast, power below 1.17 Hz was decreased after sleep deprivation. Sleep deprivation also resulted in a small compensatory increase in NREM sleep time the next day. Changes in EEG spectral power and sleep time were largely similar after 4 and 8 h sleep deprivation. REM sleep was not noticeably compensated after sleep deprivation. In conclusion, starlings display signs of NREM sleep homeostasis but the results do not support the notion of important REM sleep functions.

NREM delta stimulation following MK-801 is a response of sleep systems

1996 ◽  
Vol 76 (6) ◽  
pp. 3714-3720 ◽  
Author(s):  
I. G. Campbell ◽  
I. Feinberg
Keyword(s):  
Sleep Deprivation ◽  
Eye Movement ◽  
Time Course ◽  
Sleep Onset ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Mk 801 ◽  
Regulatory Systems ◽  
Sleep Centers ◽  
Electroencephalogram Eeg

1. We have previously shown that noncompetitive blockade of the N-methyl-D-aspartate (NMDA)-gated cation channel with ketamine or Dizocilpine maleate (MK-801) increases the intensity of non-rapid-eye-movement (NREM) delta during subsequent sleep. This delta increase [measured as integrated amplitude (IA) in 1- to 4-Hz electroencephalogram (EEG)] occurs in the 12-h period following intraperitoneal injection. However, the 12 h after drug injection is also the period in which these drugs induce neurotoxic changes, raising the possibility that the increased delta represents toxic EEG slowing rather than an increase in the physiological delta waves of NREM sleep. 2. We hypothesized that the time course of delta stimulation could be separated from the time course of neurotoxicity. We tested this hypothesis by injecting 0.3 mg/kg MK-801 at the start of the dark period (DP) and depriving rats of sleep until the onset of the light period (LP) 12 h later. 3. There were two control groups: one received MK-801 at the start of the DP with no further manipulation, and the second received a saline injection at DP onset followed by 12 h of sleep deprivation. The dependent variable was the amount of delta IA in the LP, whose onset was 12 h after MK-801 injection. Total IA in the LP was significantly greater in rats that received MK-801 followed by sleep deprivation than in rats that received sleep deprivation alone or MK-801 alone. 4. This finding indicates that delta stimulation by MK-801 is maintained over 12 h of waking, indicating that the delta increase is not due to toxic EEG slowing or persisting MK-801. Instead, NMDA channel blockade by MK-801 increases the homeostatic need for delta or else directly alters sleep regulatory systems. We speculate that these effects are mediated by hypothalamic sleep centers through control of neuroendocrine pulses that produce both NREM and rapid-eye-movement sleep. 5. Imposing a period of waking between drug administration and sleep onset may prove a generally useful strategy for determining whether a drug affects the homeostatic need for sleep or acutely stimulates sleep systems. This strategy can also help distinguish between toxic and physiological increases in delta EEG.

The Regulation of Sleep

2021 ◽  
Author(s):  
Craig Heller
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Nrem Sleep ◽  
Control Mechanisms ◽  
Rapid Eye Movement ◽  
Sleep Regulation ◽  
Short Article ◽  
Feedback Information ◽  
State Changes ◽  
And Control

The words “regulation” and “control” have different meanings. A rich literature exists on the control mechanisms of sleep—the genomic, molecular, cellular, and circuit processes responsible for arousal state changes and characteristics. The regulation of sleep refers to functions and homeostatic maintenance of those functions. Much less is known about sleep regulation than sleep control, largely because functions of sleep are still unknown. Regulation requires information about the regulated variable that can be used as feedback information to achieve optimal levels. The circadian timing of sleep is regulated, and the feedback information is entraining stimuli such as the light–dark cycle. Sleep itself is homeostatically regulated, as evidenced by sleep deprivation experiments. Eletroenceophalography (EEG) slow-wave activity (SWA) is regulated, and it appears that adenosine is the major source of feedback information, and that fact indicates an energetic function for sleep. The last aspect of sleep regulation discussed in this short article is the non-rapid eye movement (NREM) and rapid eye movement (REM) sleep cycling. Evidence is discussed that supports the argument that NREM sleep is in a homeostatic relationship with wake, and REM sleep is in a homeostatic relationship with NREM sleep.

scholarly journals MicroRNA 132 alters sleep and varies with time in brain

2011 ◽  
Vol 111 (3) ◽  
pp. 665-672 ◽  
Author(s):  
Christopher J. Davis ◽  
James M. Clinton ◽  
Ping Taishi ◽  
Stewart G. Bohnet ◽  
Kimberly A. Honn ◽  
...  
Keyword(s):  
Sleep Deprivation ◽  
Eye Movement ◽  
Dark Period ◽  
Wave Activity ◽  
Light Period ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Direct Effects ◽  
Sleep Regulation ◽  
Light Phase

MicroRNA (miRNA) levels in brain are altered by sleep deprivation; however, the direct effects of any miRNA on sleep have not heretofore been described. We report herein that intracerebroventricular application of a miRNA-132 mimetic (preMIR-132) decreased duration of non-rapid-eye-movement sleep (NREMS) while simultaneously increasing duration of rapid eye movement sleep (REMS) during the light phase. Further, preMIR-132 decreased electroencephalographic (EEG) slow-wave activity (SWA) during NREMS, an index of sleep intensity. In separate experiments unilateral supracortical application of preMIR-132 ipsilaterally decreased EEG SWA during NREMS but did not alter global sleep duration. In addition, after ventricular or supracortical injections of preMIR-132, the mimetic-induced effects were state specific, occurring only during NREMS. After local supracortical injections of the mimetic, cortical miRNA-132 levels were higher at the time sleep-related EEG effects were manifest. We also report that spontaneous cortical levels of miRNA-132 were lower at the end of the sleep-dominant light period compared with at the end of the dark period in rats. Results suggest that miRNAs play a regulatory role in sleep and provide a new tool for investigating sleep regulation.

scholarly journals The maturational trajectories of NREM and REM sleep durations differ across adolescence on both school-night and extended sleep

2012 ◽  
Vol 302 (5) ◽  
pp. R533-R540 ◽  
Author(s):  
Irwin Feinberg ◽  
Nicole M. Davis ◽  
Evan de Bie ◽  
Kevin J. Grimm ◽  
Ian G. Campbell
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Brain Activity ◽  
Physiological Role ◽  
Nrem Sleep ◽  
Sleep Time ◽  
Rapid Eye Movement ◽  
Time In Bed ◽  
Ultimate Explanation ◽  
Brain Changes

We recorded sleep electroencephalogram longitudinally across ages 9–18 yr in subjects sleeping at home. Recordings were made twice yearly on 4 consecutive nights: 2 nights with the subjects maintaining their ongoing school-night schedules, and 2 nights with time in bed extended to 12 h. As expected, school-night total sleep time declined with age. This decline was entirely produced by decreasing non-rapid eye movement (NREM) sleep. Rapid eye movement (REM) sleep durations increased slightly but significantly. NREM and REM sleep durations also exhibited different age trajectories when sleep was extended. Both durations exceeded those on school-night schedules. However, the elevated NREM duration did not change with age, whereas REM durations increased significantly. We interpret the adolescent decline in school-night NREM duration in relation to our hypothesis that NREM sleep reverses changes produced in plastic brain systems during waking. The “substrate” produced during waking declines across adolescence, because synaptic elimination decreases the intensity (metabolic rate) of waking brain activity. Declining substrate reduces both NREM intensity (i.e., delta power) and NREM duration. The absence of a decline in REM sleep duration on school-night sleep and its age-dependent increase in extended sleep pose new challenges to understanding its physiological role. Whatever their ultimate explanation, these robust findings demonstrate that the two physiological states of human sleep respond differently to the maturational brain changes of adolescence. Understanding these differences should shed new light on both brain development and the functions of sleep.

scholarly journals An Electrophysiological Marker of Arousal Level in Humans

2019 ◽  
Author(s):  
Janna D. Lendner ◽  
Randolph F. Helfrich ◽  
Bryce A. Mander ◽  
Luis Romundstad ◽  
Jack J. Lin ◽  
...  
Keyword(s):  
General Anesthesia ◽  
Eye Movement ◽  
Rem Sleep ◽  
Brain Activity ◽  
Nrem Sleep ◽  
Arousal Level ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Spectral Slope ◽  
Scale Free

AbstractDeep non-rapid eye movement sleep (NREM) – also called slow wave sleep (SWS) – and general anesthesia are prominent states of reduced arousal linked to the occurrence of slow oscillations in the electroencephalogram (EEG). Rapid eye movement (REM) sleep, however, is also associated with a diminished arousal level, but is characterized by a desynchronized, ‘wake-like’ EEG. This observation challenges the notion of oscillations as the main physiological mediator of reduced arousal. Using intracranial and surface EEG recordings in four independent data sets, we establish the 1/f spectral slope as an electrophysiological marker that accurately delineates wakefulness from anesthesia, SWS and REM sleep. The spectral slope reflects the non-oscillatory, scale-free measure of neural activity and has been proposed to index the local balance between excitation and inhibition. Taken together, these findings reconcile the long-standing paradox of reduced arousal in both REM and NREM sleep and provide a common unifying physiological principle — a shift in local Excitation/ Inhibition balance — to explain states of reduced arousal such as sleep and anesthesia in humans.Significance StatementThe clinical assessment of arousal levels in humans depends on subjective measures such as responsiveness to verbal commands. While non-rapid eye movement (NREM) sleep and general anesthesia share some electrophysiological markers, rapid eye movement sleep (REM) is characterized by a ‘wake-like’ electroencephalogram. Here, we demonstrate that non-oscillatory, scale-free electrical brain activity — recorded from both scalp electroencephalogram and intracranial recordings in humans — reliably tracks arousal levels during both NREM and REM sleep as well as under general anesthesia with propofol. Our findings suggest that non-oscillatory brain activity can be used effectively to monitor vigilance states.

Effects of selective sleep deprivation on ventilation during recovery sleep in normal humans

1992 ◽  
Vol 72 (1) ◽  
pp. 100-109 ◽  
Author(s):  
J. B. Neilly ◽  
N. B. Kribbs ◽  
G. Maislin ◽  
A. I. Pack
Keyword(s):  
Sleep Deprivation ◽  
Eye Movement ◽  
Rem Sleep ◽  
Minute Ventilation ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Rem Sleep Deprivation ◽  
Sleep Period ◽  
Recovery Sleep ◽  
The Relationship

To assess the effects of selective sleep loss on ventilation during recovery sleep, we deprived 10 healthy young adult humans of rapid-eye-movement (REM) sleep for 48 h and compared ventilation measured during the recovery night with that measured during the baseline night. At a later date we repeated the study using awakenings during non-rapid-eye-movement (NREM) sleep at the same frequency as in REM sleep deprivation. Neither intervention produced significant changes in average minute ventilation during presleep wakefulness, NREM sleep, or the first REM sleep period. By contrast, both interventions resulted in an increased frequency of breaths, in which ventilation was reduced below the range for tonic REM sleep, and in an increased number of longer episodes, in which ventilation was reduced during the first REM sleep period on the recovery night. The changes after REM sleep deprivation were largely due to an increase in the duration of the REM sleep period with an increase in the total phasic activity and, to a lesser extent, to changes in the relationship between ventilatory components and phasic eye movements. The changes in ventilation after partial NREM sleep deprivation were associated with more pronounced changes in the relationship between specific ventilatory components and eye movement density, whereas no change was observed in the composition of the first REM sleep period. These findings demonstrate that sleep deprivation leads to changes in ventilation during subsequent REM sleep.

scholarly journals Electroencephalographic changes associated with subjective under- and overestimation of sleep duration

SLEEP ◽  
2020 ◽  
Vol 43 (11) ◽  
Author(s):  
Sandro Lecci ◽  
Jacinthe Cataldi ◽  
Monica Betta ◽  
Giulio Bernardi ◽  
Raphaël Heinzer ◽  
...  
Keyword(s):  
Eye Movement ◽  
Sleep Duration ◽  
Spectral Power ◽  
Brain Activity ◽  
Nrem Sleep ◽  
Brain Regions ◽  
Population Based ◽  
Rapid Eye Movement ◽  
Clear Cut ◽  
Eeg Activation

Abstract Feeling awake although sleep recordings indicate clear-cut sleep sometimes occurs in good sleepers and to an extreme degree in patients with so-called paradoxical insomnia. It is unknown what underlies sleep misperception, as standard polysomnographic (PSG) parameters are often normal in these cases. Here we asked whether regional changes in brain activity could account for the mismatch between objective and subjective total sleep times (TST). To set cutoffs and define the norm, we first evaluated sleep perception in a population-based sample, consisting of 2,092 individuals who underwent a full PSG at home and estimated TST the next day. We then compared participants with a low mismatch (normoestimators, n = 1,147, ±0.5 SD of mean) with those who severely underestimated (n = 52, <2.5th percentile) or overestimated TST (n = 53, >97.5th percentile). Compared with normoestimators, underestimators displayed higher electroencephalographic (EEG) activation (beta/delta power ratio) in both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep, while overestimators showed lower EEG activation (significant in REM sleep). To spatially map these changes, we performed a second experiment, in which 24 healthy subjects and 10 insomnia patients underwent high-density sleep EEG recordings. Similarly to underestimators, patients displayed increased EEG activation during NREM sleep, which we localized to central-posterior brain areas. Our results indicate that a relative shift from low- to high-frequency spectral power in central-posterior brain regions, not readily apparent in conventional PSG parameters, is associated with underestimation of sleep duration. This challenges the concept of sleep misperception, and suggests that instead of misperceiving sleep, insomnia patients may correctly perceive subtle shifts toward wake-like brain activity.

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