Partitioning of inhaled ventilation between the nasal and oral routes during sleep in normal subjects

2003 ◽  
Vol 94 (3) ◽  
pp. 883-890 ◽  
Author(s):  
Michael F. Fitzpatrick ◽  
Helen S. Driver ◽  
Neela Chatha ◽  
Nha Voduc ◽  
Alison M. Girard

The oral and nasal contributions to inhaled ventilation were simultaneously quantified during sleep in 10 healthy subjects (5 men, 5 women) aged 43 ± 5 yr, with normal nasal resistance (mean 2.0 ± 0.3 cmH2O · l−1 · s−1) by use of a divided oral and nasal mask. Minute ventilation awake (5.9 ± 0.3 l/min) was higher than that during sleep (5.2 ± 0.3 l/min; P < 0.0001), but there was no significant difference in minute ventilation between different sleep stages ( P = 0.44): stage 2 5.3 ± 0.3, slow-wave 5.2 ± 0.2, and rapid-eye-movement sleep 5.2 ± 0.2 l/min. The oral fraction of inhaled ventilation during wakefulness (7.6 ± 4%) was not significantly different from that during sleep (4.3 ± 2%; mean difference 3.3%, 95% confidence interval −2.1–8.8%, P = 0.19), and no significant difference ( P = 0.14) in oral fraction was observed between different sleep stages: stage two 5.1 ± 2.8, slow-wave 4.2 ± 1.8, rapid-eye-movement 3.1 ± 1.7%. Thus the inhaled oral fraction in normal subjects is small and does not change significantly with sleep stage.

1985 ◽  
Vol 59 (2) ◽  
pp. 384-391 ◽  
Author(s):  
D. P. White ◽  
J. V. Weil ◽  
C. W. Zwillich

Recent investigation suggests that both ventilation (VE) and the chemical sensitivity of the respiratory control system correlate closely with measures of metabolic rate [O2 consumption (VO2) and CO2 production (VCO2)]. However, these associations have not been carefully investigated during sleep, and what little information is available suggests a deterioration of the relationships. As a result we measured VE, ventilatory pattern, VO2, and VCO2 during sleep in 21 normal subjects (11 males and 10 females) between the ages of 21 and 77 yr. When compared with values for awake subjects, expired ventilation decreased 8.2 +/- 2.3% (SE) during sleep and was associated with a 8.5 +/- 1.6% decrement in VO2 and a 12.3 +/- 1.7% reduction in VCO2, all P less than 0.01. The decrease in ventilation was a product primarily of a significant decrease in tidal volume with little change in frequency. None of these findings were dependent on sleep stage with results in rapid-eye-movement (REM) and non-rapid-eye-movement sleep being similar. Through all sleep stages ventilation remained tightly correlated with VO2 and VCO2 both within a given individual and between subjects. Although respiratory rhythmicity was somewhat variable during REM sleep, minute ventilation continued to correlate with VO2 and VCO2. None of the parameters described above were influenced by age or gender, with male and female subjects demonstrating similar findings. Ten of the subjects demonstrated at least occasional apneas. These individuals, however, were not found to differ from those without apnea in any other measure of ventilation or metabolic rate.


SLEEP ◽  
2021 ◽  
Author(s):  
Brian Geuther ◽  
Mandy Chen ◽  
Raymond J Galante ◽  
Owen Han ◽  
Jie Lian ◽  
...  

Abstract Study Objectives Sleep is an important biological process that is perturbed in numerous diseases, and assessment its substages currently requires implantation of electrodes to carry out electroencephalogram/electromyogram (EEG/EMG) analysis. Although accurate, this method comes at a high cost of invasive surgery and experts trained to score EEG/EMG data. Here, we leverage modern computer vision methods to directly classify sleep substages from video data. This bypasses the need for surgery and expert scoring, provides a path to high-throughput studies of sleep in mice. Methods We collected synchronized high-resolution video and EEG/EMG data in 16 male C57BL/6J mice. We extracted features from the video that are time and frequency-based and used the human expert-scored EEG/EMG data to train a visual classifier. We investigated several classifiers and data augmentation methods. Results Our visual sleep classifier proved to be highly accurate in classifying wake, non-rapid eye movement sleep (NREM), and rapid eye movement sleep (REM) states, and achieves an overall accuracy of 0.92 +/- 0.05 (mean +/- SD). We discover and genetically validate video features that correlate with breathing rates, and show low and high variability in NREM and REM sleep, respectively. Finally, we apply our methods to non-invasively detect that sleep stage disturbances induced by amphetamine administration. Conclusions We conclude that machine learning based visual classification of sleep is a viable alternative to EEG/EMG based scoring. Our results will enable non-invasive high-throughput sleep studies and will greatly reduce the barrier to screening mutant mice for abnormalities in sleep.


1991 ◽  
Vol 70 (6) ◽  
pp. 2574-2581 ◽  
Author(s):  
D. J. Tangel ◽  
W. S. Mezzanotte ◽  
D. P. White

We propose that a sleep-induced decrement in the activity of the tensor palatini (TP) muscle could induce airway narrowing in the area posterior to the soft palate and therefore lead to an increase in upper airway resistance in normal subjects. We investigated the TP to determine the influence of sleep on TP muscle activity and the relationship between changing TP activity and upper airway resistance over the entire night and during short sleep-awake transitions. Seven normal male subjects were studied on a single night with wire electrodes placed in both TP muscles. Sleep stage, inspiratory airflow, transpalatal pressure, and TP moving time average electromyogram (EMG) were continuously recorded. In addition, in two of the seven subjects the activity (EMG) of both the TP and the genioglossus muscle simultaneously was recorded throughout the night. Upper airway resistance increased progressively from wakefulness through the various non-rapid-eye-movement sleep stages, as has been previously described. The TP EMG did not commonly demonstrate phasic activity during wakefulness or sleep. However, the tonic EMG decreased progressively and significantly (P less than 0.05) from wakefulness through the non-rapid-eye-movement sleep stages [awake, 4.6 +/- 0.3 (SE) arbitrary units; stage 1, 2.6 +/- 0.3; stage 2, 1.7 +/- 0.5; stage 3/4, 1.5 +/- 0.8]. The mean correlation coefficient between TP EMG and upper airway resistance across all sleep states was (-0.46). This mean correlation improved over discrete sleep-awake transitions (-0.76). No sleep-induced decrement in the genioglossus activity was observed in the two subjects studied.(ABSTRACT TRUNCATED AT 250 WORDS)


1984 ◽  
Vol 56 (3) ◽  
pp. 671-677 ◽  
Author(s):  
C. M. Shapiro ◽  
C. C. Goll ◽  
G. R. Cohen ◽  
I. Oswald

Heat production during sleep was studied by continuous indirect calorimetry with simultaneous electroencephalographic monitoring. Controlling for gross influences on heat production, comparisons of heat production during different sleep stages showed heat production in stage 4 sleep to be significantly lower than in other sleep stages. There appeared to be a gradation in heat production in non-rapid-eye-movement stages of sleep with stage 2 higher and stage 4 lower than stage 3. Heat production in stage 4 was less variable than in any other sleep stage. Both the level and variability of heat production was similar in stage 2 and rapid-eye-movement sleep. Heat production during the night was 9% lower than during resting wakefulness. The average heat production in stage 4 sleep was 14.4% lower than resting wakeful values.


1989 ◽  
Vol 66 (3) ◽  
pp. 1373-1382 ◽  
Author(s):  
R. M. Aronson ◽  
E. Onal ◽  
D. W. Carley ◽  
M. Lopata

To determine upper airway and respiratory muscle responses to nasal continuous negative airway pressure (CNAP), we quantitated the changes in diaphragmatic and genioglossal electromyographic activity, inspiratory duration, tidal volume, minute ventilation, and end-expiratory lung volume (EEL) during CNAP in six normal subjects during wakefulness and five during sleep. During wakefulness, CNAP resulted in immediate increases in electromyographic diaphragmatic and genioglossal muscle activity, and inspiratory duration, preserved or increased tidal volume and minute ventilation, and decreased EEL. During non-rapid-eye-movement and rapid-eye-movement sleep, CNAP was associated with no immediate muscle or timing responses, incomplete or complete upper airway occlusion, and decreased EEL. Progressive diaphragmatic and genioglossal responses were observed during non-rapid-eye-movement sleep in association with arterial O2 desaturation, but airway patency was not reestablished until further increases occurred with arousal. These results indicate that normal subjects, while awake, can fully compensate for CNAP by increasing respiratory and upper airway muscle activities but are unable to do so during sleep in the absence of arousal. This sleep-induced failure of load compensation predisposes the airways to collapse under conditions which threaten airway patency during sleep. The abrupt electromyogram responses seen during wakefulness and arousal are indicative of the importance of state effects, whereas the gradual increases seen during sleep probably reflect responses to changing blood gas composition.


2019 ◽  
Author(s):  
Sarah K. Schäfer ◽  
Benedikt E. Wirth ◽  
Marlene Staginnus ◽  
Nicolas Becker ◽  
Tanja Michael ◽  
...  

SummaryNumerous studies have shown that sleep enhances the consolidation of episodic memory. However, it remains unclear whether this consolidation benefit is moderated by the emotional valence of the learned material. To clarify whether sleep selectively enhances the consolidation of emotional material, we conducted a meta-analysis including N = 1,059 observations. Overall, our results do not support this hypothesis. When only studies with a sleep-group wake-group comparison were included in the analysis (k = 22), the retention advantage for emotional over neutral material was not significantly different between sleep and wake groups. When studies initially lacking a wake-control group were included in the analysis after statistical estimation of wake-group parameters, the retention advantage for emotional material was significantly larger in wake-groups than in sleep-groups (k = 34). Interestingly, however, an additional analysis of k = 8 studies investigating the selective effects of rapid-eye-movement sleep and slow-wave sleep on emotional memory consolidation provided evidence for a selective enhancement of emotional over neutral memory consolidation after rapid-eye-movement sleep compared to slow-wave sleep. These results suggest that sleep does not generally enhance emotional memory consolidation over neutral memory consolidation. However, specific sleep stages might preferentially enhance consolidation of emotional and neutral material, respectively.


2014 ◽  
Vol 13 (2) ◽  
pp. 155-162 ◽  
Author(s):  
Péter Przemyslaw Ujma ◽  
Péter Simor ◽  
Raffaele Ferri ◽  
Dániel Fabó ◽  
Anna Kelemen ◽  
...  

2003 ◽  
Vol 285 (1) ◽  
pp. R99-R109 ◽  
Author(s):  
Hitoshi Yoshida ◽  
Takeshi Kubota ◽  
James M. Krueger

Sleep is regulated in part by the brain cytokine network, including tumor necrosis factor-α (TNF-α). TNF-α activates the transcription factor nuclear factor-κB, which in turn promotes transcription of many genes, including cyclooxygenase-2 (COX-2). COX-2 is in the brain and is an enzyme responsible for production of prostaglandin D2. The hypothesis that central COX-2 plays a role in the regulation of spontaneous and TNF-α-induced sleep was investigated. Three doses (0.5, 5, and 50 μg) of NS-398, a highly selective COX-2 inhibitor, were injected intracerebroventricularly. The highest dose decreased non-rapid eye movement sleep. The intermediate and highest doses decreased electroencephalographic slow-wave activity; the greatest reduction occurred after 50 μg of NS-398 during the first 3-h postinjection period. Rapid eye movement sleep and brain temperature were not altered by any dose of NS-398. Pretreatment of rabbits with 5 or 50 μg of NS-398 blocked the TNF-α-induced increases in non-rapid eye movement sleep, electroencephalographic slow-wave activity, and brain temperature. These data suggest that COX-2 is involved in the regulation of spontaneous and TNF-α-induced sleep.


1995 ◽  
Vol 78 (5) ◽  
pp. 1688-1698 ◽  
Author(s):  
K. W. Saupe ◽  
C. A. Smith ◽  
K. S. Henderson ◽  
J. A. Dempsey

The purpose of this study was to determine the effects of changing blood pressure in the carotid sinus (Pcs) on ventilatory output during wakefulness and non-rapid-eye-movement sleep in unanesthetized dogs. Eight dogs were chronically instrumented so that ventilation, heart rate, and blood pressure could be measured while pressure in the isolated carotid sinus was rapidly changed by means of an extracorporeal perfusion circuit. Raising Pcs 35–75 mmHg consistently reduced ventilation 15–40% in a dose-response fashion, with little or no further diminution in minute ventilation as Pcs was further increased > 75 mmHg above control level. This decrease in minute ventilation was immediate, due primarily to a decrease in tidal volume, and was sustained over the 20-s period of elevated Pcs. Increases in Pcs also caused immediate sustained reductions in systemic blood pressure and heart rate, both of which also fell in a dose-dependent fashion. The ventilatory and systemic cardiovascular responses to increased Pcs were the same during wakefulness and non-rapid-eye-movement sleep. Decreasing Pcs 40–80 mmHg caused a sudden carotid chemoreceptor-mediated hyperpnea that was eliminated by hyperoxia. We conclude that increasing Pcs causes a reflex inhibition of ventilation and that this reflex may play a role in sleep-disordered breathing.


2020 ◽  
Vol 10 (6) ◽  
pp. 343 ◽  
Author(s):  
Serena Scarpelli ◽  
Aurora D’Atri ◽  
Chiara Bartolacci ◽  
Maurizio Gorgoni ◽  
Anastasia Mangiaruga ◽  
...  

Several findings support the activation hypothesis, positing that cortical arousal promotes dream recall (DR). However, most studies have been carried out on young participants, while the electrophysiological (EEG) correlates of DR in older people are still mostly unknown. We aimed to test the activation hypothesis on 20 elders, focusing on the Non-Rapid Eye Movement (NREM) sleep stage. All the subjects underwent polysomnography, and a dream report was collected upon their awakening from NREM sleep. Nine subjects were recallers (RECs) and 11 were non-RECs (NRECs). The delta and beta EEG activity of the last 5 min and the total NREM sleep was calculated by Fast Fourier Transform. Statistical comparisons (RECs vs. NRECs) revealed no differences in the last 5 min of sleep. Significant differences were found in the total NREM sleep: the RECs showed lower delta power over the parietal areas than the NRECs. Consistently, statistical comparisons on the activation index (delta/beta power) revealed that RECs showed a higher level of arousal in the fronto-temporal and parieto-occipital regions than NRECs. Both visual vividness and dream length are positively related to the level of activation. Overall, our results are consistent with the view that dreaming and the storage of oneiric contents depend on the level of arousal during sleep, highlighting a crucial role of the temporo-parietal-occipital zone.


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