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.

Heterogeneous activity level of jaw-closing and -opening muscles and its association with arousal levels during sleep in the guinea pig

2010 ◽  
Vol 298 (1) ◽  
pp. R34-R42 ◽  
Author(s):  
Takafumi Kato ◽  
Yuji Masuda ◽  
Hayato Kanayama ◽  
Norimasa Nakamura ◽  
Atsushi Yoshida ◽  
...  
Keyword(s):  
Heart Rate ◽  
Eye Movement ◽  
Rem Sleep ◽  
Muscle Activity ◽  
Guinea Pigs ◽  
Nrem Sleep ◽  
Activity Level ◽  
Jaw Muscles ◽  
High Activity Level ◽  
Motor Activities

Exaggerated jaw motor activities during sleep are associated with muscle symptoms in the jaw-closing rather than the jaw-opening muscles. The intrinsic activity of antagonistic jaw muscles during sleep remains unknown. This study aims to assess the balance of muscle activity between masseter (MA) and digastric (DG) muscles during sleep in guinea pigs. Electroencephalogram (EEG), electroocculogram, and electromyograms (EMGs) of dorsal neck, MA, and DG muscles were recorded with video during sleep-wake cycles. These variables were quantified for each 10-s epoch. The magnitude of muscle activity during sleep in relation to mean EMG activity of total wakefulness was up to three times higher for MA muscle than for DG muscle for nonrapid eye movement (NREM) and rapid-eye-movement (REM) sleep. Although the activity level of the two jaw muscles fluctuated during sleep, the ratio of activity level for each epoch was not proportional. Epochs with a high activity level for each muscle were associated with a decrease in δEEG power and/or an increase in heart rate in NREM sleep. However, this association with heart rate and activity levels was not observed in REM sleep. These results suggest that in guinea pigs, the magnitude of muscle activity for antagonistic jaw muscles is heterogeneously modulated during sleep, characterized by a high activity level in the jaw-closing muscle. Fluctuations in the activity are influenced by transient arousal levels in NREM sleep but, in REM sleep, the distinct controls may contribute to the fluctuation. The above intrinsic characteristics could underlie the exaggeration of jaw motor activities during sleep (e.g., sleep bruxism).

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 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.

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.

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.

State-dependent effects of light-dark cycle on somatosensory and visual cortex EEG in rats

2005 ◽  
Vol 289 (4) ◽  
pp. R1083-R1089 ◽  
Author(s):  
Tadanobu Yasuda ◽  
Kyo Yasuda ◽  
Richard A. Brown ◽  
James M. Krueger
Keyword(s):  
Visual Cortex ◽  
Dark Period ◽  
Afferent Input ◽  
Light Period ◽  
Wave Band ◽  
Rapid Eye Movement Sleep ◽  
State Dependent ◽  
Eeg Power ◽  
Wake State ◽  
Constant Dark

Somatosensory (SSctx) and visual cortex (Vctx) EEG were evaluated in rats under a 12:12-h light-dark (LD) cycle and under constant light (LL) or constant dark (DD) in each sleep or wake state. Under LD conditions during light period, relative Vctx EEG slow-wave activity (SWA) was higher than that of the SSctx, whereas during dark period, relative Vctx EEG SWA was lower than in the SSctx. These effects were state specific, occurring only during non-rapid eye movement sleep (NREMS). Under LL conditions, the duration of REMS and NREMS during the period that would have been dark if the LD cycle had continued (subjective dark period) was greater than under LD conditions. DD conditions had little effect on the duration of NREMS and REMS. SSctx and Vctx EEG SWA were suppressed by LL during the subjective dark period; however, the degree of Vctx SWA suppression was smaller than that of the SSctx. DD conditions during the subjective light period enhanced SSctx SWA, whereas Vctx SWA was suppressed. Under LL conditions during the subjective dark period, Vctx EEG power was higher than that of the SSctx across a broad frequency range during NREMS, REMS, and wakefulness. During DD, SSctx EEG power during NREMS was higher than that of the Vctx in the delta wave band, whereas SSctx power during REMS and wakefulness was higher than that of the Vctx in frequencies higher than 8 Hz. We concluded that the SSctx and Vctx EEGs are differentially affected by light during subsequent sleep. Results provide support for the notion that regional sleep intensity is dependent on prior regional afferent input.

Interhemispheric Sleep EEG Asymmetry in the Rat is Enhanced by Sleep Deprivation

2002 ◽  
Vol 88 (5) ◽  
pp. 2280-2286 ◽  
Author(s):  
Vladyslav V. Vyazovskiy ◽  
Alexander A. Borbély ◽  
Irene Tobler
Keyword(s):  
Sleep Deprivation ◽  
Rem Sleep ◽  
Low Frequency ◽  
Nrem Sleep ◽  
Light Period ◽  
Sleep Eeg ◽  
Hemispheric Dominance ◽  
Eeg Asymmetry ◽  
Low Frequency Power ◽  
Frequency Power

Vigilance state-related topographic variations of electroencephalographic (EEG) activity have been reported in humans and animals. To investigate their possible functional significance, the cortical EEG of the rat was recorded from frontal and parietal derivations in both hemispheres. Records were obtained for a 24-h baseline day, 6-h sleep deprivation (SD), and subsequent 18-h recovery. During the baseline 12-h light period, the main sleep period of the rat, low-frequency (<7.0 Hz) power in the non-rapid eye-movement (NREM) sleep EEG declined progressively. Left-hemispheric predominance of low-frequency power at the parietal derivations was observed at the beginning of the light period when sleep pressure is high due to preceding spontaneous waking. The left-hemispheric dominance changed to a right-hemispheric dominance in the course of the 12-h rest-phase when sleep pressure dissipated. During recovery from SD, both low-frequency power and parietal left-hemispheric predominance were enhanced. The increase in low-frequency power in NREM sleep observed after SD at the frontal site was larger than at the parietal site. However, frontally no interhemispheric differences were present. In REM sleep, power in the theta band (5.25–8.0 Hz) exhibited a right-hemispheric predominance. In contrast to NREM sleep, the hemispheric asymmetry showed no trend during baseline and was not affected by SD. Use-dependent local changes may underlie the regional differences in the low-frequency NREM sleep EEG within and between hemispheres. The different interhemispheric asymmetries in NREM and REM sleep suggest that the two sleep states may subserve different functions in the brain.

Altered sleep and behavioral activity phenotypes in PER3-deficient mice

2011 ◽  
Vol 301 (6) ◽  
pp. R1821-R1830 ◽  
Author(s):  
Sibah Hasan ◽  
Daan R. van der Veen ◽  
Raphaelle Winsky-Sommerer ◽  
Derk-Jan Dijk ◽  
Simon N. Archer
Keyword(s):  
Rem Sleep ◽  
Wheel Running ◽  
Nrem Sleep ◽  
Light Period ◽  
Behavioral Activity ◽  
Dark Phase ◽  
Running Activity ◽  
Sleep Homeostasis ◽  
Wheel Running Activity ◽  
Delta Activity

Sleep homeostasis and circadian rhythmicity interact to determine the timing of behavioral activity. Circadian clock genes contribute to circadian rhythmicity centrally and in the periphery, but some also have roles within sleep regulation. The clock gene Period3 ( Per3) has a redundant function within the circadian system and is associated with sleep homeostasis in humans. This study investigated the role of PER3 in sleep/wake activity and sleep homeostasis in mice by recording wheel-running activity under baseline conditions in wild-type (WT; n = 54) and in PER3-deficient ( Per3−/−; n = 53) mice, as well as EEG-assessed sleep before and after 6 h of sleep deprivation in WT ( n = 7) and Per3−/− ( n = 8) mice. Whereas total activity and vigilance states did not differ between the genotypes, the temporal distribution of wheel-running activity, vigilance states, and EEG delta activity was affected by genotype. In Per3−/− mice, running wheel activity was increased, and REM sleep and NREM sleep were reduced in the middle of the dark phase, and delta activity was enhanced at the end of the dark phase. At the beginning of the baseline light period, there was less wakefulness and more REM and NREM sleep in Per3−/− mice. Per3−/− mice spent less time in wakefulness and more time in NREM sleep in the light period immediately after sleep deprivation, and REM sleep accumulated more slowly during the recovery dark phase. These data confirm a role for PER3 in sleep-wake timing and sleep homeostasis.

Expanding Nielsen's covert REM model, questioning Solms's approach to dreaming and REM sleep, and reinterpreting the Vertes & Eastman view of REM sleep and memory

2000 ◽  
Vol 23 (6) ◽  
pp. 981-983 ◽  
Author(s):  
Robert D. Ogilvie ◽  
Tomoka Takeuchi ◽  
Timothy I. Murphy
Keyword(s):  
Cognitive Processes ◽  
Rem Sleep ◽  
Process Model ◽  
Nrem Sleep ◽  
Present Problem ◽  
Dream Theory

Nielsen's covert REM process model explains much of the mentation found in REM and NREM sleep, but stops short of postulating an interaction of waking cognitive processes with the dream mechanisms of REM sleep. It ranks with the Hobson et al. paper as a major theoretical advance. The Solms article does not surmount the ever-present problem of defining dreams in a manner conducive to advancing dream theory. Vertes & Eastman review the REM sleep and learning literature, but make questionable assumptions in doing so.[Hobson et al.; Nielsen; Solms; Vertes & Eastman]

scholarly journals Dual orexin receptor antagonists increase sleep and cataplexy in wild type mice

SLEEP ◽  
2019 ◽  
Vol 43 (6) ◽  
Author(s):  
Carrie E Mahoney ◽  
Takatoshi Mochizuki ◽  
Thomas E Scammell
Keyword(s):  
Rem Sleep ◽  
Positive Emotions ◽  
Dark Period ◽  
Nrem Sleep ◽  
Wild Type ◽  
Receptor Antagonists ◽  
Dose Dependent Fashion ◽  
Dose Dependent ◽  
Higher Doses ◽  
Desirable Effect

Abstract Orexin receptor antagonists are clinically useful for treating insomnia, but thorough blockade of orexin signaling could cause narcolepsy-like symptoms. Specifically, while sleepiness is a desirable effect, an orexin antagonist could also produce cataplexy, sudden episodes of muscle weakness often triggered by strong, positive emotions. In this study, we examined the effects of dual orexin receptor antagonists (DORAs), lemborexant (E2006) and almorexant, on sleep–wake behavior and cataplexy during the dark period in wild-type (WT) mice and prepro-orexin knockout (OXKO) mice. In WT mice, lemborexant at 10 and 30 mg/kg quickly induced NREM sleep in a dose-dependent fashion. In contrast, lemborexant did not alter sleep–wake behavior in OXKO mice. Under the baseline condition, cataplexy was rare in lemborexant-treated WT mice, but when mice were given chocolate as a rewarding stimulus, lemborexant dose-dependently increased cataplexy. Almorexant produced similar results. Collectively, these results demonstrate that DORAs potently increase NREM and REM sleep in mice via blockade of orexin signaling, and higher doses can cause cataplexy when co-administered with a likely rewarding stimulus.

Sign in / Sign up

Export Citation Format

Share Document