Influence of hypothalamic and ambient temperatures on sleep in kangaroo rats

1979 ◽  
Vol 237 (1) ◽  
pp. R80-R88 ◽  
Author(s):  
S. Sakaguchi ◽  
S. F. Glotzbach ◽  
H. C. Heller

Unanesthetized, unrestrained kangaroo rats (Dipodomys) were studied to examine the changes in the frequency and duration of sleep states caused by long-term manipulations of hypothalamic temperature (Thy) at a thermoneutral (30 degrees C) and a low (20 degrees C) ambient temperature (Ta). A cold stimulus present in either the hypothalamus or the skin decreased both the total sleep time (TST) and the ratio of paradoxical sleep (PS) to TST. At a low Ta, TST, but not the PS-to-TST ratio, was increased by raising Thy, indicating that a cold peripheral stimulus could differentially inhibit PS. At a thermoneutral Ta, cooling Thy decreased both TST and the PS/TST. Changes in the amount of PS were due largely to changes in the frequency, but not the duration, of individual episodes of PS, suggesting that the transition to PS is partially dependent on the thermoregulatory conditions existing during slow-wave sleep (SWS). These results are consistent with the recent findings that the thermoregulatory system is functional during SWS but is inhibited or inactivated during PS.

Biosensors ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 185
Author(s):  
Dean J. Miller ◽  
Gregory D. Roach ◽  
Michele Lastella ◽  
Aaron T. Scanlan ◽  
Clint R. Bellenger ◽  
...  

The aims of this study were to: (1) compare actigraphy (ACTICAL) and a commercially available sleep wearable (i.e., WHOOP) under two functionalities (i.e., sleep auto-detection (WHOOP-AUTO) and manual adjustment of sleep (WHOOP-MANUAL)) for two-stage categorisation of sleep (sleep or wake) against polysomnography, and; (2) compare WHOOP-AUTO and WHOOP-MANUAL for four-stage categorisation of sleep (wake, light sleep, slow wave sleep (SWS), or rapid eye movement sleep (REM)) against polysomnography. Six healthy adults (male: n = 3; female: n = 3; age: 23.0 ± 2.2 yr) participated in the nine-night protocol. Fifty-four sleeps assessed by ACTICAL, WHOOP-AUTO and WHOOP-MANUAL were compared to polysomnography using difference testing, Bland–Altman comparisons, and 30-s epoch-by-epoch comparisons. Compared to polysomnography, ACTICAL overestimated total sleep time (37.6 min) and underestimated wake (−37.6 min); WHOOP-AUTO underestimated SWS (−15.5 min); and WHOOP-MANUAL underestimated wake (−16.7 min). For ACTICAL, sensitivity for sleep, specificity for wake and overall agreement were 98%, 60% and 89%, respectively. For WHOOP-AUTO, sensitivity for sleep, wake, and agreement for two-stage and four-stage categorisation of sleep were 90%, 60%, 86% and 63%, respectively. For WHOOP-MANUAL, sensitivity for sleep, wake, and agreement for two-stage and four-stage categorisation of sleep were 97%, 45%, 90% and 62%, respectively. WHOOP-AUTO and WHOOP-MANUAL have a similar sensitivity and specificity to actigraphy for two-stage categorisation of sleep and can be used as a practical alternative to polysomnography for two-stage categorisation of sleep and four-stage categorisation of sleep.


1977 ◽  
Vol 233 (5) ◽  
pp. R213-R221 ◽  
Author(s):  
J. M. Walker ◽  
S. F. Glotzbach ◽  
R. J. Berger ◽  
H. C. Heller

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.


Author(s):  
Sophie West

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.


SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A269-A269
Author(s):  
Sarah Sussman ◽  
Ashwin Ananth ◽  
Elie Fares ◽  
Maurits Boon ◽  
Colin Huntley ◽  
...  

Abstract Introduction Sleep disruption is common among hospitalized patients due to psychological, physiological, and environmental reasons including illness, pain, anxiety, invasive interventions, frequent monitoring, and stimuli, especially noise and light. The AASM has published guidelines for the use of actigraphy in the outpatient setting, but there is a paucity of literature evaluating the validity of actigraphy in inpatients. The aim of this study is to evaluate sleep in hospitalized general medicine patients undergoing sleep medicine consultation using actigraphy and qualitative surveys. Methods A single-site prospective study in hospitalized medicine patients. Patients were observed with a Fitbit® Charge3 wrist actigraphy device overnight, then administered 7 surveys: Richards-Campbell Sleep Questionnaire (RCSQ), qualitative questionnaires assessing sleep history, sleep hygiene, barriers to sleep, STOP-BANG, Epworth Sleepiness Scale (ESS), and Patient-Health Questionniare-2 (PHQ-2). Actigraphy data including total sleep time, slow wave sleep time, and number of awakenings was compared with patient-reported data. Results In preliminary analysis, six patients met inclusion criteria and underwent sleep medicine consultation, overnight actigraphy, and completed 7 surveys. Based on subjective sleep history questionnaires, average total sleep time was 437 + 215 minutes. Actigraphy revealed average total sleep time was 228 + 80 minutes with an average of 3.6 nocturnal awakenings. Increased number of awakenings on actigraphy was not correlated with increased number of awakenings by survey. The most frequently reported barriers to sleep on patient surveys were pain and being woken up for labs or vital signs. The average STOP-BANG score was 6 out of 8 and average ESS was 14 out of 24. Conclusion Restorative sleep warrants consideration alongside complex medical care during hospitalization. Patients experience decreased total sleep time and increased number of awakenings while in the hospital compared with their subjective estimates of sleep at home. Actigraphy provides a non-invasive and reliable way to monitor some sleep parameters in the inpatient setting. An elevated STOP-BANG score could represent sleep disordered breathing and impact perceptions of sleep quality. Patient-identified barriers to sleep are targets for quality improvement. Future studies should compare inpatient actigraphy data to polysomnographic data and the effect of sleep-directed interventions on sleep quality in the hospital. Support (if any):


2019 ◽  
Vol 98 (10) ◽  
pp. 1155-1160 ◽  
Author(s):  
Elena V. Katamanova ◽  
N. V. Slivnitsyna ◽  
E. N. Korchuganova ◽  
O. I. Shevchenko

Introduction. In the Irkutsk region, chronic mercury intoxication (CRI) occupies a leading place among occupational neurointoxications. An organic personality disorder with insomnia is one of the manifestations of brain damage in CRI. The aim of the study was to establish diagnostic criteria for secondary insomnia in patients with professional CRI for the selection of effective treatment. Material and methods. The study involved 30 people in the long-term CRI and 30 people in the comparison group with sleep disorders that are not in contact with harmful factors. Electroencephalographic, polysomnographic research and questioning were carried out with the assessment of the subjective characteristics of sleep. Information was processed using the Statistika 6.0 application package. Results. It was shown that CRI patients were shown to complain statistically significantly more frequent sleep disturbances than in the comparison group (p = 0.0003), difficulty in maintaining sleep (p = 0.004). As a result of EEG in the group of patients in the long-term CRI, the integral index and the ratio α/β were statistically significantly different from those in the comparison group, and according to the results of polysomnography, more pronounced qualitative and quantitative violations of the night sleep pattern were found in CRI patients; as a decrease in total sleep time (p = 0.0001), increase in sleep time (p = 0.008), number of activations and total wakefulness inside sleep (p = 0.03), decrease in sleep efficiency index (p = 0.006) and increase in an integrative sleep quality index (p = 0.03). According to the discriminant analysis, 4 criteria for diagnosing insomnia in CRI were established: total sleep time (min.), duration of the first stage of slow sleep (%), rhythm ratio α/β, EEG (%) and integral EEG index (%). Conclusion. Considering the data obtained, it is possible to improve approaches to treating insomnia in CRI by prescribing a complex of treatment, including cognitive-behavioral therapy, antidepressants with a sedative effect, as well as alpha training using biofeedback.


2012 ◽  
Vol 110 (1) ◽  
pp. 63-72 ◽  
Author(s):  
William D. S. Killgore ◽  
Vincent F. Capaldi ◽  
Melanie L. Guerrero

The relations of nighttime Polysomnographic sleep variables with daytime sleepiness scores on the Epworth Sleepiness Scale were assessed in a retrospective chart review of 38 patients referred to a sleep clinic. Of the variables assessed, only slow wave sleep was statistically significantly correlated with daytime sleepiness, regardless of whether the analysis was based on absolute minutes of slow wave sleep or percentage of total sleep time spent in slow wave sleep. Stepwise linear regression suggested that other Polysomnographic variables did not provide additional predictive value beyond the two indices of slow wave sleep. Apparently, reduced quantity of slow wave sleep was weakly but significantly related to increased daytime sleepiness among these sleep-clinic patients.


2015 ◽  
Vol 30 (5) ◽  
pp. 461-469 ◽  
Author(s):  
Gloria Bedini ◽  
Anna Bersano ◽  
Davide Rossi Sebastiano ◽  
Davide Sattin ◽  
Francesca Ciaraffa ◽  
...  

Background. Sleep evaluation is increasingly being used as prognostic tool in patients with disorders of consciousness, but, surprisingly, the role of Period3 (Per3) gene polymorphism has never been evaluated. Objective. The aim of this study was to investigate the contribution of Per3 genotype on sleep quantity and consciousness recovery level in patients with disorders of consciousness (DOC). Methods. In this observational study, we evaluated 71 patients with DOC classified as vegetative state/unresponsive wakefulness syndrome or minimally conscious state. Demographic and clinical data were collected and a standardised diagnostic workup, including a polysomnographic record, was applied. After informed consent provided by proxy, genomic DNA was obtained and Per3 polymorphism was analysed by polymerase chain reaction to identify 5/5, 4/5, or 4/4 genotype. Results. Per35/5genotype was found in 12.7% of our DOC patients. The median total Coma Recovery Scale–revised score in Per35/5carriers was significantly higher than 4/4 genotype (10, range 5-16 vs 7, range 4-11; post hoc P = .036). Moreover, total sleep time seemed to be higher in 5/5 genotype ( 5/5, 221 minutes, range 88-515 minutes; 4/4, 151.5 minutes, range 36-477 minutes; and 4/5, 188 minutes, range 44-422 minutes). Conclusion. For the first time we have shown a possible association between Per3 polymorphism and consciousness recovery level in DOC patients. Even though the exact molecular mechanism has not been defined, we speculate that its effect is mediated by higher total sleep time and slow wave sleep, which would improve the preservation of main cerebral connections.


1977 ◽  
Vol 38 (3) ◽  
pp. 445-454 ◽  
Author(s):  
P-L. Toutain ◽  
Claire Toutain ◽  
A. J. F. Webster ◽  
J. D. McDonald

1. Changes in energy expenditure associated with sleep and activity, age and fatness were measured in sheep. States of vigilance were defined according to electrophysiological records as awake, drowsy, slow-wave sleep (SWS) and paradoxical sleep (PS; Ruckebusch, 1972). Energy expenditure was determined from respiratory exchange. Three groups, each of four sheep were used; yearlings, old (4-6 years of age) fat and old thin sheep. Body fat content was estimated from deuterium oxide space.2. The amount of time spent by sheep from each group at each state of vigilance was similar, total ‘sleep’ time being 200-250 min/night.3. The absolute decrease in energy expenditure during drowsiness and sleep was similar for all groups of sheep. The difference between SWS and lying awake was 20-27 J/kg body-weight (W)0.75 per min. Heat production was about the same for SWS and PS.4. The energy cost of rumination was about 0.34 kJ/kg W per h.5. The increase in heat production during standing consisted of the energy cost of standing, approximately 0.7 kJ/kg W per h, and the energy cost of changing position, approximately 47 J/kg W.6. The old thin sheep had a slightly higher heat production on a per kg total W0.75 basis than the old fat sheep, but this difference largely disappeared when heat production was related to ‘lean’ W. On average energy expenditure was approximately 25% lower in the old sheep than in the yearling animals. This difference could not be related to difference in activity or in the energy costs of activity per unit of time.


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