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 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.

Vigilance states, EEG spectra, and cortical temperature in the guinea pig

1993 ◽  
Vol 264 (6) ◽  
pp. R1125-R1132 ◽  
Author(s):  
I. Tobler ◽  
P. Franken ◽  
K. Jaggi
Keyword(s):  
Guinea Pig ◽  
Rem Sleep ◽  
Guinea Pigs ◽  
Process Model ◽  
Dark Period ◽  
Nrem Sleep ◽  
Light Period ◽  
Recording Time ◽  
Cortical Temperature ◽  
Eeg Power

Vigilance states, electroencephalogram (EEG) power spectra (0.25-25.0 Hz), and cortical temperature (TCRT) were obtained in nine guinea pigs for 24 h in a 12:12-h light-dark (LD 12:12) schedule. Sleep was markedly polyphasic and fragmented and amounted to 32% of recording time, which is a low value compared with sleep in other rodents. There was 6.8% more sleep in the light period than in the dark period. EEG power density in non-rapid eye movement (NREM) sleep showed no significant temporal trend within the light or the dark period. The homeostatic aspects of sleep regulation, as proposed in the two-process model, can account for the slow-wave activity (SWA) pattern also in the guinea pig: The small 24-h amplitude of the sleep-wakefulness pattern resulted in a small, 12% decline of SWA within the light period. In contrast to more distinctly nocturnal rodents, SWA in the dark period was not higher than in the light period. TCRT showed no difference between the light and the dark period. TCRT in REM sleep and waking was higher than TCRT in NREM sleep. TCRT increased after the transition from NREM sleep to either REM sleep or waking, and decreased in the last minute before the transition and after the transition from waking to NREM sleep. Motor activity measured in six animals for 11 days in constant darkness showed no apparent rhythm in three animals and a significant circadian rhythm in three others. Our data support the notion that guinea pigs exhibit only a weak circadian rest-activity rhythm.

scholarly journals Quantitative electroencephalography measures in rapid eye movement and nonrapid eye movement sleep are associated with apnea–hypopnea index and nocturnal hypoxemia in men

SLEEP ◽  
2019 ◽  
Vol 42 (7) ◽  
Author(s):  
Sarah L Appleton ◽  
Andrew Vakulin ◽  
Angela D’Rozario ◽  
Andrew D Vincent ◽  
Alison Teare ◽  
...  
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Nrem Sleep ◽  
Community Dwelling ◽  
Total Power ◽  
Apnea Hypopnea Index ◽  
Rapid Eye Movement ◽  
Quantitative Electroencephalography ◽  
Nocturnal Hypoxemia ◽  
Eeg Power

AbstractStudy ObjectivesQuantitative electroencephalography (EEG) measures of sleep may identify vulnerability to obstructive sleep apnea (OSA) sequelae, however, small clinical studies of sleep microarchitecture in OSA show inconsistent alterations. We examined relationships between quantitative EEG measures during rapid eye movement (REM) and non-REM (NREM) sleep and OSA severity among a large population-based sample of men while accounting for insomnia.MethodsAll-night EEG (F4-M1) recordings from full in-home polysomnography (Embletta X100) in 664 men with no prior OSA diagnosis (age ≥ 40) were processed following exclusion of artifacts. Power spectral analysis included non-REM and REM sleep computed absolute EEG power for delta, theta, alpha, sigma, and beta frequency ranges, total power (0.5–32 Hz) and EEG slowing ratio.ResultsApnea–hypopnea index (AHI) ≥10/h was present in 51.2% (severe OSA [AHI ≥ 30/h] 11.6%). In mixed effects regressions, AHI was positively associated with EEG slowing ratio and EEG power across all frequency bands in REM sleep (all p < 0.05); and with beta power during NREM sleep (p = 0.06). Similar associations were observed with oxygen desaturation index (3%). Percentage total sleep time with oxygen saturation <90% was only significantly associated with increased delta, theta, and alpha EEG power in REM sleep. No associations with subjective sleepiness were observed.ConclusionsIn a large sample of community-dwelling men, OSA was significantly associated with increased EEG power and EEG slowing predominantly in REM sleep, independent of insomnia. Further study is required to assess if REM EEG slowing related to nocturnal hypoxemia is more sensitive than standard PSG indices or sleepiness in predicting cognitive decline.

Negative pressure-induced deformation of the upper airway causes central apnea in awake and sleeping dogs

1996 ◽  
Vol 80 (5) ◽  
pp. 1528-1539 ◽  
Author(s):  
C. A. Harms ◽  
Y. J. Zeng ◽  
C. A. Smith ◽  
E. H. Vidruk ◽  
J. A. Dempsey
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Negative Pressure ◽  
Upper Airway ◽  
Nrem Sleep ◽  
Electromyographic Activity ◽  
Rapid Eye Movement ◽  
Topical Anesthetic ◽  
Control Value ◽  
States Of Consciousness

We investigated the effects of negative pressure (NP) in the isolated upper airway (UA) in three unanesthetized dogs. The UA was isolated, and the dogs breathed through an endotracheal tube while wearing a fitted fiberglass snout mask. NP (-2 to -32 cmH2O) was applied in a square wave below the larynx or at the snout at end expiration and was held until inspiratory effort during wakefulness, non-rapid-eye-movement (NREM) sleep, and rapid-eye-movement (REM) sleep. During all states of consciousness, NP applied to the UA prolonged expiratory time (TE) 1) below a threshold of -8 to -10 cmH2O, which coincided with closure of the oro- and/or velopharynx; and 2) in a progressive fashion at more negative pressures than threshold, up to a mean apneic length of 324% of the control value (or 13.9 s) at -30 cmH2O. TE prolongation was less during REM sleep at a given NP (P < 0.05). Augmented tonic genioglossal electromyographic activity also occurred with the applied NP during wakefulness and NREM sleep but not with REM sleep. NP (-20 to -32 cmH2O) applied as a brief pulse (300-500 ms) during NREM sleep caused transient airway occlusion, terminated the breath during inspiration, and prolonged TE when applied at end expiration. Central apneas always persisted beyond the termination of the UA closure. TE prolongation in response to NP persisted in the presence of a topical anesthetic nebulized through the UA sufficient to abolish the laryngeal gag reflexes. We conclude that UA closure and deformation will cause significant TE prolongation during all states of consciousness and activation of the genioglossus muscle during wakefulness and NREM sleep but not during REM sleep.

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 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.

scholarly journals Sound disrupts sleep-associated brain oscillations in rodents according to its meaning

2021 ◽  
Author(s):  
Philipp van Kronenberg ◽  
Linus Milinski ◽  
Zoë Kruschke ◽  
Livia de Hoz
Keyword(s):  
Eye Movement ◽  
Rem Sleep ◽  
Sensory Gating ◽  
Nrem Sleep ◽  
Brain Oscillations ◽  
Sleep Phase ◽  
Fast Decrease ◽  
Per Se ◽  
Eeg Power ◽  
Danger Detection

SummarySleep is essential but poses a risk to the animal. Filtering acoustic information according to its relevance, a process generally known as sensory gating, is crucial during sleep to ensure a balance between rest and danger detection. The mechanisms of this sensory gating and its specificity are not understood. Here, we tested the effect that sounds of different meaning had on sleep-associated ongoing oscillations. We recorded EEG and EMG from mice during rapid-eye movement (REM) and non-REM (NREM) sleep while presenting sounds with or without behavioural relevance. We found that sound presentation per se, in the form of an unfamiliar neutral sound, elicited a weak or no change in the sleep-dependent EEG power during NREM and REM sleep. In contrast, the presentation of a sound previously conditioned in an aversive task, elicited a clear and fast decrease in the sleep-dependent EEG power during both sleep phases, suggesting a transition to lighter sleep without awakening. The observed changes generally weakened over training days and were not present in animals that failed to learn. Interestingly, the effect could be generalized to unfamiliar neutral sounds if presented following conditioned training, an effect that depended on sleep phase and sound type. The data demonstrate that sounds are differentially gated during sleep depending on their meaning and that this process is reflected in disruption of sleep-associated brain oscillations without an effect on behavioural arousal.

scholarly journals REM sleep-dependent short-term and long-term hourglass processes in the ultradian organization and recovery of REM sleep in the rat

SLEEP ◽  
2020 ◽  
Vol 43 (8) ◽  
Author(s):  
Adrián Ocampo-Garcés ◽  
Alejandro Bassi ◽  
Enzo Brunetti ◽  
Jorge Estrada ◽  
Ennio A Vivaldi
Keyword(s):  
Sleep Deprivation ◽  
Rem Sleep ◽  
Transition Probability ◽  
Nrem Sleep ◽  
Short Term ◽  
Rem Sleep Deprivation ◽  
Sleep Episode ◽  
Organization Of Sleep ◽  
Sleep Transition

Abstract Study Objectives To evaluate the contribution of long-term and short-term REM sleep homeostatic processes to REM sleep recovery and the ultradian organization of the sleep wake cycle. Methods Fifteen rats were sleep recorded under a 12:12 LD cycle. Animals were subjected during the rest phase to two protocols (2T2I or 2R2I) performed separately in non-consecutive experimental days. 2T2I consisted of 2 h of total sleep deprivation (TSD) followed immediately by 2 h of intermittent REM sleep deprivation (IRD). 2R2I consisted of 2 h of selective REM sleep deprivation (RSD) followed by 2 h of IRD. IRD was composed of four cycles of 20-min RSD intervals alternating with 10 min of sleep permission windows. Results REM sleep debt that accumulated during deprivation (9.0 and 10.8 min for RSD and TSD, respectively) was fully compensated regardless of cumulated NREM sleep or wakefulness during deprivation. Protocol 2T2I exhibited a delayed REM sleep rebound with respect to 2R2I due to a reduction of REM sleep transitions related to enhanced NREM sleep delta-EEG activity, without affecting REM sleep consolidation. Within IRD permission windows there was a transient and duration-dependent diminution of REM sleep transitions. Conclusions REM sleep recovery in the rat seems to depend on a long-term hourglass process activated by REM sleep absence. Both REM sleep transition probability and REM sleep episode consolidation depend on the long-term REM sleep hourglass. REM sleep activates a short-term REM sleep refractory period that modulates the ultradian organization of sleep states.

Reflexive and orienting properties of REM sleep dreaming and eye movements

2000 ◽  
Vol 23 (6) ◽  
pp. 950-950 ◽  
Author(s):  
John Herman
Keyword(s):  
Eye Movements ◽  
Rem Sleep ◽  
Dimensional Space ◽  
Brain Activity ◽  
Three Dimensional ◽  
Nrem Sleep ◽  
Subcortical Structures ◽  
States Of Consciousness ◽  
Activation System ◽  
Three Dimensional Space

In this manuscript Hobson et al. propose a model exploring qualitative differences between the three states of consciousness, waking, NREM sleep, and REM sleep, in terms of state-related brain activity. The model consists of three factors, each of which varies along a continuum, creating a three-dimensional space: activation (A), information flow (I), and mode of information processing (M). Hobson has described these factors previously (1990; 1992a). Two of the dimensions, activation and modulation, deal directly with subcortical influences upon cortical structures – the reticular activation system, with regard to the activation dimension and the locus coeruleus and the pontine raphe neuclei, with regard to the modulation dimension. The focus of this review is a further exploration of the interaction between dreaming and the cortical and subcortical structures relevant to REM sleep eye movements.[Hobson et al. ]

Melatonin and S-20098 increase REM sleep and wake-up propensity without modifying NREM sleep homeostasis

1997 ◽  
Vol 272 (4) ◽  
pp. R1189-R1196 ◽  
Author(s):  
C. Cajochen ◽  
K. Krauchi ◽  
D. Mori ◽  
P. Graw ◽  
A. Wirz-Justice
Keyword(s):  
Power Density ◽  
Rem Sleep ◽  
Core Body Temperature ◽  
Nrem Sleep ◽  
Acute Administration ◽  
Placebo Condition ◽  
Evening Dose ◽  
Sleep Episode ◽  
Temperature Rhythm ◽  
Eeg Power

The pineal hormone melatonin has been implicated in the circadian regulation of sleep. In a crossover design, we investigated the effect of acute administration of 5 mg melatonin and a melatonin agonist (S-20098, 5 and 100 mg) in healthy young men when given 5 h before bedtime on sleep structure and electroencephalogram (EEG) power density. Each trial comprised a baseline, a treatment, and a posttreatment sleep episode. Relative to the placebo condition, all treatments phase advanced the core body temperature rhythm [Krauchi, K., C. Cajochen, D. Mori, C. Hetsch, and A. Wirz-Justice. Sleep Res. 24: 526, 1995; and Krauchi, K., C. Cajochen, D. Mori, and A. Wirz-Justice. Am. J. Physiol. 272 (Regulatory Integrative Comp. Physiol. 41): R1178-1188, 1997]. Rapid eye movement (REM) sleep was increased after both melatonin and S-20098. This increase in REM sleep was most pronounced in the first REM sleep episode. On the posttreatment night after melatonin and S-20098 administration, more wakefulness was present in the latter one-half of the sleep episode. EEG power density between 0.25 and 20 Hz during either non-REM (NREM) or REM sleep did not differ from placebo. Thus a single early evening dose of melatonin or the agonist S-20098 increases REM sleep propensity and advances sleep termination while, at the same time, the EEG in NREM sleep remains unaffected.

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