Hypoxic insomnia: effects of carbon monoxide and acclimatization

1984 ◽  
Vol 57 (6) ◽  
pp. 1696-1703 ◽  
Author(s):  
J. R. Pappenheimer
Keyword(s):  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Nrem Sleep ◽  
Slow Waves ◽  
Partial Recovery ◽  
Peripheral Chemoreceptors ◽  
Loss Of Weight ◽  
Normal Sleep ◽  
Loss Of Appetite ◽  
Electroencephalogram Eeg

Hypoxia causes severe disruption of both rapid-eye-movement (REM) and non-REM (NREM) sleep. Experiments were performed on rats to determine if hypoxic insomnia is mediated by peripheral chemoreceptors and if normal sleep is restored during acclimatization to low O2. Novel methods were devised to measure distribution of amplitudes of cortical slow waves during NREM sleep and to detect REM sleep from the ratio of amplitudes of theta-to delta-frequency bands in the hippocampal electroencephalogram (EEG). Acute exposure of rats to 10.5% O2 (5,030 m altitude equivalent) during daylight hours virtually abolished REM sleep and shifted the distribution of amplitudes of slow-wave sleep EEG toward awake values. Similar disruption of sleep occurred during inhalation of 0.05% CO with steady-state carboxyhemoglobin of approximately 35%. Respiratory rate and alveolar ventilation were greatly increased by 10.5% O2 but were unaffected by CO. Therefore, hypoxic disruption of sleep was not mediated by peripheral chemoreceptors regulating breathing. Partial recovery of sleep occurred after 1-2 wk of hypoxia, but both REM and NREM were still subnormal after 1 mo. Decreased intensity of NREM sleep during hypoxia, measured by amplitude of cortical slow waves, may explain the disparity between subjective complaints of insomnia at altitude and evaluations of sleep by direct observation or by conventional EEG. Loss of appetite, loss of weight, irritability, and other symptoms of altitude sickness may be related to hypoxic insomnia.

scholarly journals The relationship between fasting-induced torpor, sleep and waking in laboratory mice

SLEEP ◽  
2021 ◽  
Author(s):  
Yi-Ge Huang ◽  
Sarah J Flaherty ◽  
Carina A Pothecary ◽  
Russell G Foster ◽  
Stuart N Peirson ◽  
...  
Keyword(s):  
Body Temperature ◽  
Rem Sleep ◽  
Brain Activity ◽  
Mammalian Species ◽  
Nrem Sleep ◽  
Laboratory Mice ◽  
State Classification ◽  
Metabolic Suppression ◽  
The Relationship ◽  
Electroencephalogram Eeg

Abstract Study objectives Torpor is a regulated and reversible state of metabolic suppression used by many mammalian species to conserve energy. Whereas the relationship between torpor and sleep has been well-studied in seasonal hibernators, less is known about the effects of fasting-induced torpor on states of vigilance and brain activity in laboratory mice. Methods Continuous monitoring of electroencephalogram (EEG), electromyogram (EMG) and surface body temperature was undertaken in adult, male C57BL/6 mice over consecutive days of scheduled restricted feeding. Results All animals showed bouts of hypothermia that became progressively deeper and longer as fasting progressed. EEG and EMG were markedly affected by hypothermia, although the typical electrophysiological signatures of NREM sleep, REM sleep and wakefulness enabled us to perform vigilance-state classification in all cases. Consistent with previous studies, hypothermic bouts were initiated from a state indistinguishable from NREM sleep, with EEG power decreasing gradually in parallel with decreasing surface body temperature. During deep hypothermia, REM sleep was largely abolished, and we observed shivering-associated intense bursts of muscle activity. Conclusions Our study highlights important similarities between EEG signatures of fasting-induced torpor in mice, daily torpor in Djungarian hamsters and hibernation in seasonally-hibernating species. Future studies are necessary to clarify the effects on fasting-induced torpor on subsequent sleep.

Parasomnias

2018 ◽  
Author(s):  
KyoungBin Im
Keyword(s):  
Mental Disorders ◽  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Rem Sleep Behavior Disorder ◽  
Behavior Disorder ◽  
Nrem Sleep ◽  
Normal Subjects ◽  
Related Phenomenon ◽  
Sleep Behavior ◽  
Diagnostic And Statistical Manual

Parasomnias have long been recognized as part of sleep-related disorders or diseases in the mental disorders classification system such as Diagnostic and Statistical Manual of Mental Disorders. Nevertheless, many parasomnia symptoms are considered as a transient deviation from the norm in otherwise normal subjects due to disrupted status of consciousness. Sleep states are classified as rapid eye movement (REM) sleep and non-REM (NREM) sleep; similarly, parasomnias are classified as NREM-related parasomnias and REM-related parasomnias. NREM-related parasomnias share common pathophysiology of arousal-related phenomenon out of slow-wave sleep. Although listed as REM parasomnia disorders, nightmares and sleep paralysis are still considered comorbid symptoms or signs of other sleep disorders or mental disorders. Only REM sleep behavior disorder (RBD) is considered a relatively homogenous disease entity among all parasomnia diagnoses. Although RBD is the most newly added disorder entity in parasomnias, it is the most rigorously studied parasomnia such as RBD is strongly and clearly associated with concomitant or future developing neurodegenerative disease. This review contains 1 figure, 4 tables, and 18 references. Key Words: confusional arousals, dream enactment, pseudo-RBD, REM sleep behavior disorder, sleep-related eating, sleep terror, sleepwalking

Opioids cause dissociated states of consciousness in C57BL/6J mice

2021 ◽  
Author(s):  
Christopher B O'Brien ◽  
Clarence E Locklear ◽  
Zachary T Glovak ◽  
Diana Zebadúa Unzaga ◽  
Helen A Baghdoyan ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Neuronal Excitability ◽  
Nrem Sleep ◽  
Temporal Organization ◽  
Saline Control ◽  
Organization Of Sleep ◽  
States Of Consciousness ◽  
Surgical Recovery ◽  
Eeg Power ◽  
Electroencephalogram Eeg

The electroencephalogram (EEG) provides an objective, neural correlate of consciousness. Opioid receptors modulate mammalian neuronal excitability, and this fact was used to characterize how opioids administered to mice alter EEG power and states of consciousness. The present study tested the hypothesis that antinociceptive doses of fentanyl, morphine, or buprenorphine differentially alter the EEG and states of sleep and wakefulness in adult, male C57BL/6J mice. Mice were anesthetized and implanted with telemeters that enabled wireless recordings of cortical EEG and electromyogram (EMG). After surgical recovery, EEG and EMG were used to objectively score states of consciousness as wakefulness, rapid eye movement (REM) sleep, or non-REM (NREM) sleep. Measures of EEG power (dB) were quantified as delta (0.5 to 4 Hz), theta (4 to 8 Hz), alpha (8 to 13 Hz), sigma (12 to 15 Hz), beta (13 to 30 Hz), and gamma (30 to 60 Hz). Compared to saline (control), fentanyl and morphine decreased NREM sleep, morphine eliminated REM sleep, and buprenorphine eliminated NREM sleep and REM sleep. Opioids significantly and differentially disrupted the temporal organization of sleep/wake states, altered specific EEG frequency bands, and caused dissociated states of consciousness. The results are discussed relative to the fact that opioids, pain, and sleep modulate interacting states of consciousness.

scholarly journals Bidirectional Interaction of Hippocampal Ripples and Cortical Slow Waves Leads to Coordinated Spiking Activity During NREM Sleep

2020 ◽  
Vol 31 (1) ◽  
pp. 324-340
Author(s):  
Pavel Sanda ◽  
Paola Malerba ◽  
Xi Jiang ◽  
Giri P Krishnan ◽  
Jorge Gonzalez-Martinez ◽  
...  
Keyword(s):  
Slow Wave ◽  
Memory Consolidation ◽  
Slow Wave Sleep ◽  
Nrem Sleep ◽  
Slow Waves ◽  
Slow Oscillation ◽  
Cortical Input ◽  
Sharp Wave ◽  
Up States ◽  
Intracranial Recordings

Abstract The dialogue between cortex and hippocampus is known to be crucial for sleep-dependent memory consolidation. During slow wave sleep, memory replay depends on slow oscillation (SO) and spindles in the (neo)cortex and sharp wave-ripples (SWRs) in the hippocampus. The mechanisms underlying interaction of these rhythms are poorly understood. We examined the interaction between cortical SO and hippocampal SWRs in a model of the hippocampo–cortico–thalamic network and compared the results with human intracranial recordings during sleep. We observed that ripple occurrence peaked following the onset of an Up-state of SO and that cortical input to hippocampus was crucial to maintain this relationship. A small fraction of ripples occurred during the Down-state and controlled initiation of the next Up-state. We observed that the effect of ripple depends on its precise timing, which supports the idea that ripples occurring at different phases of SO might serve different functions, particularly in the context of encoding the new and reactivation of the old memories during memory consolidation. The study revealed complex bidirectional interaction of SWRs and SO in which early hippocampal ripples influence transitions to Up-state, while cortical Up-states control occurrence of the later ripples, which in turn influence transition to Down-state.

Sleep-Related Electrophysiology and Behavior of Tinamous (Eudromia elegans): Tinamous Do Not Sleep Like Ostriches

2017 ◽  
Vol 89 (4) ◽  
pp. 249-261 ◽  
Author(s):  
Ryan K. Tisdale ◽  
Alexei L. Vyssotski ◽  
John A. Lesku ◽  
Niels C. Rattenborg
Keyword(s):  
Eye Movements ◽  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Muscle Tone ◽  
Slow Waves ◽  
Sleep State ◽  
Rapid Eye Movements ◽  
Electrophysiological Studies ◽  
Taxonomic Groups ◽  
And Behavior

The functions of slow wave sleep (SWS) and rapid eye movement (REM) sleep, distinct sleep substates present in both mammals and birds, remain unresolved. One approach to gaining insight into their function is to trace the evolution of these states through examining sleep in as many taxonomic groups as possible. The mammalian and avian clades are each composed of two extant groups, i.e., the monotremes (echidna and platypus) and therian (marsupial and eutherian [or placental]) mammals, and Palaeognaths (cassowaries, emus, kiwi, ostriches, rheas, and tinamous) and Neognaths (all other birds) among birds. Previous electrophysiological studies of monotremes and ostriches have identified a unique “mixed” sleep state combining features of SWS and REM sleep unlike the well-delineated sleep states observed in all therian mammals and Neognath birds. In the platypus this state is characterized by periods of REM sleep-related myoclonic twitching, relaxed skeletal musculature, and rapid eye movements, occurring in conjunction with SWS-related slow waves in the forebrain electroencephalogram (EEG). A similar mixed state was also observed in ostriches; although in addition to occurring during periods with EEG slow waves, reduced muscle tone and rapid eye movements also occurred in conjunction with EEG activation, a pattern typical of REM sleep in Neognath birds. Collectively, these studies suggested that REM sleep occurring exclusively as an integrated state with forebrain activation might have evolved independently in the therian and Neognath lineages. To test this hypothesis, we examined sleep in the elegant crested tinamou (Eudromia elegans), a small Palaeognath bird that more closely resembles Neognath birds in size and their ability to fly. A 24-h period was scored for sleep state based on electrophysiology and behavior. Unlike ostriches, but like all of the Neognath birds examined, all indicators of REM sleep usually occurred in conjunction with forebrain activation in tinamous. The absence of a mixed REM sleep state in tinamous calls into question the idea that this state is primitive among Palaeognath birds and therefore birds in general.

Sleep and hibernation in ground squirrels (Citellus spp): electrophysiological observations

1977 ◽  
Vol 233 (5) ◽  
pp. R213-R221 ◽  
Author(s):  
J. M. Walker ◽  
S. F. Glotzbach ◽  
R. J. Berger ◽  
H. C. Heller
Keyword(s):  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Dark Period ◽  
Total Sleep Time ◽  
Brain Temperature ◽  
Sleep Time ◽  
Light Period ◽  
Ground Squirrels ◽  
Sleep Stages ◽  
Electroencephalogram Eeg

Electroencephalogram (EEG), electrooculogram, electromyogram, and electrocardiogram were recorded from ground squirrels (Citellus beldingi and C. lateralis) during the summer and also during the hibernation season. Summer recordings revealed that the animals spent an average of 66% of the 24-h period asleep (49% of the 12-h light period and 84% of the 12-h dark period); 19% of the total sleep time (TST) consisted of rapid-eye-movement (REM) sleep, and 81% of TST consisted of slow-wave sleep (SWS). Recordings obtained during the hibernation season showed that hibernation was entered through sleep, but the distribution of sleep states was different than in euthermic sleep. During the early entrance when brain temperature (Tbr) was between 35 and 25 degrees C, the animals were asleep 88% of the time, but only 10% of the TST was spent in REM sleep. The EEG amplitude declined with decreased Tbr so that classical sleep stages could not be identified below a Tbr of 25 degrees C. The frequency of the EEG increased as Tbr decreased; but activity in the 0–4 cycles/s band occupied the majority of the record even at a Tbr of 10 degrees C. Below a Tbr of 10 degrees C the EEG was isoelectric except for intermittent bursts of spindles. It was concluded from these and other results that the entrance into hibernation represents an extension of the thermoregulatory adjustments that occur during SWS.

Disorders of sleep

2018 ◽  
Author(s):  
Sophie West
Keyword(s):  
Chronic Disease ◽  
Eye Movement ◽  
Rem Sleep ◽  
Excessive Daytime Sleepiness ◽  
Slow Wave Sleep ◽  
Total Sleep Time ◽  
Sleep Time ◽  
Sleep Stages ◽  
Normal Sleep ◽  
Sedative Drugs

Typically, disorders of sleep cause disturbance either to the sufferer or to their bed partner. If total sleep time is reduced, this may lead to problems with excessive daytime sleepiness, which can affect work, driving, concentration, and relationships. ‘Sleepiness’ implies an intrusive desire to fall asleep, caused by some form of sleep deprivation or sedative drugs; this is different from ‘tiredness’, which implies general fatigue, lethargy, and exhaustion and is caused by a range of conditions, including depression, chronic disease, or a busy lifestyle. Adults sleep on average for 8 hours a night. Normal sleep consists of periods of deep or slow-wave sleep, interspersed with shorter periods of dreaming or rapid-eye-movement (REM) sleep. Periods of REM sleep lengthen towards the morning and hence some people remember their dreams on waking. Different disorders of sleep can affect any of these sleep stages.

scholarly journals The relationship between fasting-induced torpor, sleep and wakefulness in the laboratory mouse

2020 ◽  
Author(s):  
Yi G. Huang ◽  
Sarah J. Flaherty ◽  
Carina A. Pothecary ◽  
Russell G. Foster ◽  
Stuart N. Peirson ◽  
...  
Keyword(s):  
Body Temperature ◽  
Rem Sleep ◽  
Brain Activity ◽  
Mammalian Species ◽  
Laboratory Mouse ◽  
Nrem Sleep ◽  
Early Ontogeny ◽  
State Classification ◽  
The Relationship ◽  
Electroencephalogram Eeg

AbstractTorpor is a regulated reversible state of metabolic suppression used by many mammalian species to conserve energy. Although torpor has been studied extensively in terms of general physiology, metabolism and neuroendocrinology, the effects of hypometabolism and associated hypothermia on brain activity and states of vigilance have received little attention. Here we performed continuous monitoring of electroencephalogram (EEG), electromyogram (EMG) and peripheral body temperature in adult, male C57BL/6 mice over consecutive days of scheduled restricted feeding. All animals showed prominent bouts of hypothermia that became progressively deeper and longer as fasting progressed. EEG and EMG were markedly affected by hypothermia, although the typical electrophysiological signatures of NREM sleep, REM sleep and wakefulness allowed us to perform vigilance-state classification in all cases. Invariably, hypothermia bouts were initiated from a state indistinguishable from NREM sleep, with EEG power decreasing gradually in parallel with decreasing body temperature. Furthermore, during deep hypothermia REM sleep was largely abolished, but we observed brief and intense bursts of muscle activity, which resembled the regular motor discharges seen during early ontogeny associated with immature sleep patterns. We conclude that torpor and sleep are electrophysiologically on a continuum, and that, in order for torpor to occur, mice need to first transition through euthermic sleep.

Time course of EEG power density during long sleep in humans

1990 ◽  
Vol 258 (3) ◽  
pp. R650-R661 ◽  
Author(s):  
D. J. Dijk ◽  
D. P. Brunner ◽  
A. A. Borbely
Keyword(s):  
Slow Wave ◽  
Process Model ◽  
Time Course ◽  
Slow Wave Sleep ◽  
Nrem Sleep ◽  
Sleep Stages ◽  
Base Line ◽  
Sleep Regulation ◽  
Recovery Sleep ◽  
Electroencephalogram Eeg

In nine subjects sleep was recorded under base-line conditions with a habitual bedtime (prior wakefulness 16 h; lights off at 2300 h) and during recovery from sleep deprivation with a phase-advanced bedtime (prior wakefulness 36 h; lights off at 1900 h). The duration of phase-advanced recovery sleep was greater than 12 h in all subjects. Spectral analysis of the sleep electroencephalogram (EEG) revealed that slow-wave activity (SWA; 0.75-4.5 Hz) in non-rapid-eye-movement (NREM) sleep was significantly enhanced during the first two NREM-REM sleep cycles of displaced recovery sleep. The sleep stages 3 and 4 (slow-wave sleep) and SWA decreased monotonically over the first three and four NREM-REM cycles of, respectively, base-line and recovery sleep. The time course of SWA in base-line and recovery sleep could be adequately described by an exponentially declining function with a horizontal asymptote. The results are in accordance with the two-process model of sleep regulation in which it is assumed that SWA rises as a function of the duration of prior wakefulness and decreases exponentially as a function of prior sleep. We conclude that the present data do not provide evidence for a 12.5-h sleep-dependent rhythm of deep NREM sleep.

scholarly journals Homeostatic sleep regulation in the absence of the circadian sleep‐regulating component: effect of short light–dark cycles on sleep–wake stages and slow waves

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Örs Szalontai ◽  
Attila Tóth ◽  
Máté Pethő ◽  
Dóra Keserű ◽  
Tünde Hajnik ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Slow Wave Sleep ◽  
Complex Interaction ◽  
Slow Waves ◽  
Sleep Regulation ◽  
Dark Cycle ◽  
Lighting Condition ◽  
Initial Decrease ◽  
Sleep Drive ◽  
Effect Of Light

Abstract Background Aside from the homeostatic and circadian components, light has itself an important, direct as well as indirect role in sleep regulation. Light exerts indirect sleep effect by modulating the circadian rhythms. Exposure to short light-dark cycle (LD 1:1, 1:1 h light - dark) eliminates the circadian sleep regulatory component but direct sleep effect of light could prevail. The aim of the present study was to examine the interaction between the light and the homeostatic influences regarding sleep regulation in a rat model. Methods Spontaneous sleep–wake and homeostatic sleep regulation by sleep deprivation (SD) and analysis of slow waves (SW) were examined in Wistar rats exposed to LD1:1 condition using LD12:12 regime as control. Results Slow wave sleep (SWS) and REM sleep were both enhanced, while wakefulness (W) was attenuated in LD1:1. SWS recovery after 6-h total SD was more intense in LD1:1 compared to LD12:12 and SWS compensation was augmented in the bright hours. Delta power increment during recovery was caused by the increase of SW number in both cases. More SW was seen during baseline in the second half of the day in LD1:1 and after SD compared to the LD12:12. Increase of SW number was greater in the bright hours compared to the dark ones after SD in LD1:1. Lights ON evoked immediate increase in W and decrease in both SWS and REM sleep during baseline LD1:1 condition, while these changes ceased after SD. Moreover, the initial decrease seen in SWS after lights ON, turned to an increase in the next 6-min bin and this increase was stronger after SD. These alterations were caused by the change of the epoch number in W, but not in case of SWS or REM sleep. Lights OFF did not alter sleep–wake times immediately, except W, which was increased by lights OFF after SD. Conclusions Present results show the complex interaction between light and homeostatic sleep regulation in the absence of the circadian component and indicate the decoupling of SW from the homeostatic sleep drive in LD1:1 lighting condition.

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