A limit cycle mathematical model of the REM sleep oscillator system

1986 ◽  
Vol 251 (6) ◽  
pp. R1011-R1029 ◽  
Author(s):  
R. W. McCarley ◽  
S. G. Massaquoi
Keyword(s):  
Mathematical Model ◽  
Limit Cycle ◽  
Rem Sleep ◽  
Time Course ◽  
Circadian Variation ◽  
Sleep Onset ◽  
Physiological Data ◽  
Sleep Cycle ◽  
Oscillator System ◽  
Circadian Phase

A limit cycle mathematical model of the rapid-eye-movement (REM) sleep oscillator system has been developed from a structural model of interaction of populations of REM-on and REM-off neurons. The marked differences in latency, amplitude, and duration of the first REM sleep period seen with circadian variation and depressive pathology are modeled by beginning the REM oscillation at different initial points relative to the final position in the limit cycle. Beginning from a point that is graphically interior to the limit cycle produces a long-latency, short-duration, and less intense first REM period. Beginning from a point graphically exterior to the limit cycle produces a short-latency, long-duration, and more intense first REM period. In the model the determinant of whether the oscillation begins exterior or interior to the limit cycle is the time course of decay of the REM-off population discharge activity at sleep onset. When this time course is made to depend on circadian phase, the model produces a very close match to the empirically observed large shifts between the first and second REM periods in duration (often a 50% change) and intensity and also closely mimics the empirically observed shifts in REM latency as human sleep begins at different circadian phases. Although this variation in limit cycle entry accounts for the major changes in REM sleep over the night, the model also postulates a continuous but small circadian variation (of the order of +/- 5% change in REM parameters) acting throughout the course of a night's sleep. Because the model is derived from actual physiological data, rather than being a purely ad hoc or phenomenological construct, it offers the possibility of direct tests of its postulates through neurobiological studies in animals, by circadian phase-related manipulations of the sleep cycle, and through perturbations of the system in humans by the use of drugs. Indeed, an explicit phase-response curve of the system to cholinergic agonists has been developed; this will permit experimental tests of the model in both animals and humans.

scholarly journals Greatest changes in objective sleep architecture during COVID-19 lockdown in night-owls with increased REM sleep

SLEEP ◽  
2021 ◽  
Author(s):  
Jean-Louis Pépin ◽  
Sébastien Bailly ◽  
Ernest Mordret ◽  
Jonathan Gaucher ◽  
Renaud Tamisier ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Sleep Onset ◽  
Eating Behaviour ◽  
Depression Scale ◽  
Severity Index ◽  
Smartphone Application ◽  
Sleep Time ◽  
Sleep Architecture ◽  
Physiological Data ◽  
Sleep Stages

Abstract Study Objectives The Covid-19 pandemic has had dramatic effects on society and people’s daily habits. In this observational study we recorded objective data on sleep macro- and microarchitecture repeatedly over several nights before and during the Covid-19 government-imposed lockdown. The main objective was to evaluate changes in patterns of sleep duration and architecture during home confinement using the pre-confinement period as a control. Methods Participants were regular users of a sleep-monitoring headband that records, stores, and automatically analyses physiological data in real time, equivalent to polysomnography. We measured: sleep onset duration (SOD), total sleep time (TST), duration of sleep stages (N2, N3 and REM), and sleep continuity. Via the user’s smartphone application participants filled-in questionnaires on how lockdown changed working hours, eating behaviour, and daily-life at home. They also filled-in the Insomnia Severity Index, reduced Morningness-Eveningness Questionnaire and Hospital Anxiety and Depression Scale questionnaires allowing us to create selected sub-groups. Results The 599 participants were mainly men (71%) of median age 47 [IQR: 36;59]. Compared to before lockdown, during lockdown individuals slept more overall (mean +3·83 min; SD: ±1.3), had less deep sleep (N3), more light sleep (N2) and longer REM sleep (mean +3·74 min; SD: ±0.8). They exhibited less week-end specific changes, suggesting less sleep restriction during the week. Changes were most pronounced in individuals reporting eveningness preferences, suggesting relative sleep deprivation in this population and exacerbated sensitivity to societal changes. Conclusions This unique dataset should help us understand the effects of lockdown on sleep architecture and on our health.

scholarly journals Commentary on the mutual interaction model of McCarley and Massaquoi for REM-NREM cycle

1986 ◽  
Vol 251 (6) ◽  
pp. R1030-R1032
Author(s):  
S. Daan ◽  
D. G. Beersma
Keyword(s):  
Limit Cycle ◽  
Initial Conditions ◽  
Circadian Variation ◽  
Sleep Onset ◽  
Interaction Model ◽  
The Other ◽  
Circadian Cycle ◽  
Rem Latency ◽  
Parameter Values ◽  
Cycle Dependence

McCarley and Massaquoi successfully simulated human REM-NREM cycle characteristics by extending the McCarley-Hobson model with two sets of assumptions, one creating limit cycle behavior, the other introducing two sources of circadian variation. We argue that the limit cycle assumptions, due to freedom in choosing parameter values, suffice to explain variation in REM across the night. Nonmonotonic circadian variation in REM latency requires a circadian cycle dependence only of initial conditions at sleep onset.

II. Muscle atonia in non-REM sleep

2002 ◽  
Vol 283 (2) ◽  
pp. R527-R532 ◽  
Author(s):  
Esther Werth ◽  
Peter Achermann ◽  
Alexander A. Borbély
Keyword(s):  
Sleep Deprivation ◽  
Rem Sleep ◽  
Time Course ◽  
Sleep Onset ◽  
Rem Sleep Deprivation ◽  
Sleep Episode ◽  
Muscle Atonia ◽  
Recovery Sleep ◽  
Before And After ◽  
Sleep Deficit

One of the hallmarks of rapid eye movement (REM) sleep is muscle atonia. Here we report extended epochs of muscle atonia in non-REM sleep (MAN). Their extent and time course was studied in a protocol that included a baseline night, a daytime sleep episode with or without selective REM sleep deprivation, and a recovery night. The distribution of the latency to the first occurrence of MAN was bimodal with a first mode shortly after sleep onset and a second mode 40 min later. Within a non-REM sleep episode, MAN showed a U-shaped distribution with the highest values before and after REM sleep. Whereas MAN was at a constant level over consecutive 2-h intervals of nighttime sleep, MAN showed high initial values when sleep began in the morning. Selective daytime REM sleep deprivation caused an initial enhancement of MAN during recovery sleep. It is concluded that episodes of MAN may represent an REM sleep equivalent and that it may be a marker of homeostatic and circadian REM sleep regulating processes. MAN episodes may contribute to the compensation of an REM sleep deficit.

157 The Circadian Variation of Sleep in Postmenopausal Women

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A64-A64
Author(s):  
Rafael Perez Medina Carballo ◽  
Anastasi Kosmadopoulos ◽  
Manon Robert ◽  
Diane Boivin
Keyword(s):  
Postmenopausal Women ◽  
Rem Sleep ◽  
Sleep Disturbances ◽  
Linear Models ◽  
Core Body Temperature ◽  
Circadian Variation ◽  
Sleep Onset ◽  
Sleep Onset Latency ◽  
Sleep Complaints

Abstract Introduction During menopause, 40-60% of women report sleep complaints. Despite the fact that menopause is associated with fluctuations in sex hormones that can affect circadian physiology, the role of circadian factors in sleep disturbances after menopause is not well understood. The present study aims to understand the circadian variation of sleep occurring after menopause. Methods Eight healthy postmenopausal women (PMW; 54.8±3.4 years, one taking hormones) without sleep complaints were enrolled and compared to previously-collected data from 12 healthy young women (YW; 25.8±3.4 years) in mid-follicular phase. Following an 8-h baseline sleep period aligned to their habitual sleep times, participants underwent a 48-h (PMW) or 72-h (YW) ultradian sleep-wake cycle procedure (USW) with 60-min wake episodes alternating with 60-min nap opportunities. Sleep was recorded with polysomnography. Circadian parameters (amplitude, phase) of core body temperature (CBT) and sleep were assessed and compared using mixed-effects linear models on the first 48 hours of USW. Sleep parameters, including total sleep time (TST), arousals, sleep onset latency (SOL), stages N1, N2, N3, REM, and wake, were compared between groups during baseline and USW. Results PMW presented earlier habitual bedtimes (23:07±00:11 vs 00:13±00:12) and rise-times (07:07±00:11 vs 08:13±00:12) compared to YW (p=0.005). There were no differences in amplitude, phase, or phase angle of CBT. An advanced acrophase of REM sleep (p=0.034) and lower amplitudes of TST, arousals, SOL, N3, and wake, were observed in PMW vs YW (p≤0.05). During baseline, PMW presented more stage N1 (p=0.030) and arousals (p<0.001) than YW. During USW, group effects were observed, with more stage N1 (p=0.007) and N2 (p=0.0007) in PMW vs YW. Significant interactions showed greater TST (p=0.009), shorter SOL (p=0.001), and more arousals (p=0.027) in PMW during the habitual day. Conclusion The primary finding in this small group of PMW with no sleep complaints was a general increase in light sleep and arousals across circadian phases. No differences in CBT rhythms were observed, whereas small differences in the circadian variation of TST, N3, and REM sleep were observed. Further studies are needed to clarify the role of circadian processes on sleep in PMW. Support (if any) Study supported by the Canadian Institutes of Health Research.

Further discussion of a model of the REM sleep oscillator

1986 ◽  
Vol 251 (6) ◽  
pp. R1033-R1036 ◽  
Author(s):  
R. W. McCarley ◽  
S. G. Massaquoi
Keyword(s):  
Simple Model ◽  
Limit Cycle ◽  
Population Decline ◽  
Sleep Onset ◽  
Initial Condition ◽  
Explicit Formulation ◽  
Circadian Phase ◽  
Rem Latency ◽  
Normal Sleep ◽  
Latency Duration

The limit cycle feature and the grounding of our model in physiology are endorsed by Daan and Beersma [Am. J. Physiol. 251 (Regulatory Integrative Comp. Physiol. 20): R1030-R1032, 1986.] as well as the fundamental postulate of the model that the latency, duration, and intensity of the first rapid-eye-movement (REM) period depends on whether the limit cycle is entered from an internal or external trajectory, and the fact that this trajectory is determined by circadian modulation of conditions at sleep onset. We describe our reasons for preferring a more explicit formulation of the sleep onset conditions than provided in our earlier “Karmal” version of this model and provide additional details of how the control of the REM-off population decline is modeled. Additional empirical evidence is cited for the continuous circadian modulation of REM cycle parameters. We emphasize that, compared with the original simple model, the present version of the model adds only one additional “free” initial condition parameter (circadian phase) that is used to model normal sleep begun at different circadian phases and the resultant variations in REM latency, duration, intensity, and period length. We present specific predictions of the model and new supporting empirical data.

The Distinctive Sleep Pattern of the Human Calcarine Cortex: A Stereo-EEG Study

SLEEP ◽  
2021 ◽  
Author(s):  
Maurizio Gorgoni ◽  
Simone Sarasso ◽  
Fabio Moroni ◽  
Ivana Sartori ◽  
Michele Ferrara ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Time Course ◽  
Sleep Eeg ◽  
Sleep Cycle ◽  
Sleep Spindles ◽  
Rise Rate ◽  
Delta Activity ◽  
Eeg Pattern ◽  
Eeg Features ◽  
Calcarine Cortex

Abstract Study Objectives The aim of the study was to describe the spontaneous electroencephalographic (EEG) features of sleep in the human calcarine cortex, comparing them with the well-established pattern of the parietal cortex. Methods We analysed pre-surgical intracerebral EEG activity in calcarine and parietal cortices during NREM and REM sleep in 7 patients with drug-resistant focal epilepsy. The time course of the EEG spectral power and NREM vs. REM differences were assessed. Sleep spindles were automatically detected. To assess homeostatic dynamics, we considered the 1 st vs. 2 nd half of the night ratio in the delta frequency range (0.5-4 Hz) and the rise rate of delta activity during the 1 st sleep cycle. Results While the parietal area showed the classically described NREM and REM sleep hallmarks, the calcarine cortex exhibited a distinctive pattern characterized by: a) the absence of sleep spindles; b) a large similarity between EEG power spectra of NREM and REM; c) reduced signs of homeostatic dynamics, with a decreased delta ratio between the 1 st and the 2 nd half of the night, a reduced rise rate of delta activity during the 1 st NREM sleep cycle, and lack of correlation between these measures. Conclusions Besides describing for the first time the peculiar sleep EEG pattern in the human calcarine cortex, our findings provide evidence that different cortical areas may exhibit specific sleep EEG pattern, supporting the view of sleep as a local process and promoting the idea that the functional role of sleep EEG features should be considered at a regional level.

Spectral and Topographic Microstructure of Brain Alpha Activity During Drowsiness at Sleep Onset and REM Sleep

2000 ◽  
Vol 14 (3) ◽  
pp. 151-158 ◽  
Author(s):  
José Luis Cantero ◽  
Mercedes Atienza
Keyword(s):  
Rem Sleep ◽  
Spectral Component ◽  
Sleep Onset ◽  
Quantitative Information ◽  
Maximum Energy ◽  
Alpha Activity ◽  
The Other ◽  
Classification Algorithms ◽  
Microstructural Properties ◽  
Brain States

Abstract High-resolution frequency methods were used to describe the spectral and topographic microstructure of human spontaneous alpha activity in the drowsiness (DR) period at sleep onset and during REM sleep. Electroencephalographic (EEG), electrooculographic (EOG), and electromyographic (EMG) measurements were obtained during sleep in 10 healthy volunteer subjects. Spectral microstructure of alpha activity during DR showed a significant maximum power with respect to REM-alpha bursts for the components in the 9.7-10.9 Hz range, whereas REM-alpha bursts reached their maximum statistical differentiation from the sleep onset alpha activity at the components between 7.8 and 8.6 Hz. Furthermore, the maximum energy over occipital regions appeared in a different spectral component in each brain activation state, namely, 10.1 Hz in drowsiness and 8.6 Hz in REM sleep. These results provide quantitative information for differentiating the drowsiness alpha activity and REM-alpha by studying their microstructural properties. On the other hand, these data suggest that the spectral microstructure of alpha activity during sleep onset and REM sleep could be a useful index to implement in automatic classification algorithms in order to improve the differentiation between the two brain states.

scholarly journals Toward asleep DBS: cortico-basal ganglia spectral and coherence activity during interleaved propofol/ketamine sedation mimics NREM/REM sleep activity

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jing Guang ◽  
Halen Baker ◽  
Orilia Ben-Yishay Nizri ◽  
Shimon Firman ◽  
Uri Werner-Reiss ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Rem Sleep ◽  
Standard Procedure ◽  
Low Frequency ◽  
Nrem Sleep ◽  
Sleep Cycle ◽  
Advanced Parkinson’S Disease ◽  
Low Frequency Power ◽  
The Brain ◽  
Frequency Power

AbstractDeep brain stimulation (DBS) is currently a standard procedure for advanced Parkinson’s disease. Many centers employ awake physiological navigation and stimulation assessment to optimize DBS localization and outcome. To enable DBS under sedation, asleep DBS, we characterized the cortico-basal ganglia neuronal network of two nonhuman primates under propofol, ketamine, and interleaved propofol-ketamine (IPK) sedation. Further, we compared these sedation states in the healthy and Parkinsonian condition to those of healthy sleep. Ketamine increases high-frequency power and synchronization while propofol increases low-frequency power and synchronization in polysomnography and neuronal activity recordings. Thus, ketamine does not mask the low-frequency oscillations used for physiological navigation toward the basal ganglia DBS targets. The brain spectral state under ketamine and propofol mimicked rapid eye movement (REM) and Non-REM (NREM) sleep activity, respectively, and the IPK protocol resembles the NREM-REM sleep cycle. These promising results are a meaningful step toward asleep DBS with nondistorted physiological navigation.

086 Sleep midpoint after job loss predicts breakfast skipping patterns

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A36-A36
Author(s):  
Leah Callovini ◽  
Gaby Gubka ◽  
Candace Mayer ◽  
Darlynn Rojo-Wissar ◽  
David Glickenstein ◽  
...  
Keyword(s):  
Job Loss ◽  
Activity Patterns ◽  
Sleep Onset ◽  
Daily Routine ◽  
Cross Sectional ◽  
Circadian Phase ◽  
Breakfast Skipping ◽  
Occupational Transitions ◽  
The Relationship ◽  
Significant Covariates

Abstract Introduction Few studies have examined circadian phase after job loss, an event that upends daily routine. It is common that a daily routine begins with the consumption of breakfast, and breakfast behavior may contribute to health status in adults. Therefore, we sought to examine whether a later midpoint of sleep was associated with breakfast skipping among adults whose schedules were no longer dictated by employment. Methods Data were obtained from the Assessing Daily Activity Patterns Through Occupational Transitions (ADAPT) study. The sample of 155 participants had involuntarily lost their jobs in the last 90 days. Both cross-sectional and 18-month longitudinal analyses assessed the relationship between sleep midpoint after job loss and current and later breakfast skipping. Assessment periods were 14 days. Sleep was measured via actigraphy, and breakfast skipping was measured via daily diary (1 = had breakfast; 0 = did not have breakfast). The midpoint of sleep was calculated as the circular center based on actigraphy sleep onset and offset times. Results The midpoint of sleep at baseline was negatively associated with breakfast consumption at baseline (B = -.09, SE = .02, p = .000). Also, a later midpoint was associated with breakfast skipping over the next 18 months (estimate = -.08; SE = .02; p = .000). Prospective findings remained significant when adjusting for gender, ethnicity, age, perceived stress, body mass index (BMI), education, and reemployment over time. Education (estimate = 14.26, SE = 6.23, p < .05) and BMI (estimate = -.51, SE = .25, p < .05) were the only significant covariates. No other sleep indices predicted breakfast behavior cross-sectionally or prospectively. Conclusion Consistent with research in adolescents, unemployed adults with a later circadian phase are more likely to skip breakfast more often. Breakfast skipping was also associated with higher BMI. Taken together, these findings provide support for the future testing of sleep/wake scheduling interventions to modify breakfast skipping and potentially mitigate weight gain after job loss. Support (if any) #1R01HL117995-01A1

Sign in / Sign up

Export Citation Format

Share Document