scholarly journals Mechanisms of the deep, slow-wave, sleep-related increase of upper airway muscle tone in healthy humans

2017 ◽  
Vol 122 (5) ◽  
pp. 1304-1312 ◽  
Author(s):  
Amelia Hicks ◽  
Jennifer M. Cori ◽  
Amy S. Jordan ◽  
Christian L. Nicholas ◽  
Leszek Kubin ◽  
...  

Upper airway muscle activity is reportedly elevated during slow-wave sleep (SWS) when compared with lighter sleep stages. To uncover the possible mechanisms underlying this elevation, we explored the correlation between different indices of central and reflex inspiratory drive, such as the changes in airway pressure and end-expiratory CO2and the changes in the genioglossus (GG) and tensor palatini (TP) muscle activity accompanying transitions from the lighter N2 to the deeper N3 stage of non-rapid eye movement (NREM) sleep in healthy young adult men. Forty-six GG and 38 TP continuous electromyographic recordings were obtained from 16 men [age: 20 ± 2.5 (SD) yr; body mass index: 22.5 ± 1.8 kg/m2] during 32 transitions from NREM stages N2 to N3. GG but not TP activity increased following transition into N3 sleep, and the increase was positively correlated with more negative airway pressure, increased end-tidal CO2, increased peak inspiratory flow, and increased minute ventilation. None of these correlations was statistically significant for TP. Complementary GG and TP single motor unit analysis revealed a mild recruitment of GG units and derecruitment of TP units during the N2 to N3 transitions. These findings suggest that, in healthy individuals, the increased GG activity during SWS is driven primarily by reflex stimulation of airway mechanoreceptors and central chemoreceptors.NEW & NOTEWORTHY The characteristic increase in the activity of the upper airway dilator muscle genioglossus during slow-wave sleep (SWS) in young healthy individuals was found to be related to increased stimulation of airway mechanoreceptors and central chemoreceptors. No evidence was found for the presence of a central SWS-specific drive stimulating genioglossus activity in young healthy individuals. However, it remains to be determined whether a central drive exists in obstructive sleep apnea patients.

1987 ◽  
Vol 62 (5) ◽  
pp. 1832-1836 ◽  
Author(s):  
F. G. Issa ◽  
S. G. McNamara ◽  
C. E. Sullivan

Previous studies have shown that the arousal threshold to hypoxia, hypercapnia, and tracheal occlusions is greatly depressed in rapid-eye-movement (REM) sleep compared with slow-wave sleep (SWS). The aim of this study was to compare the arousal thresholds in SWS and REM sleep in response to an upper airway pressure stimulus. We compared the waking responses to tracheal (T) vs. nasal (N) occlusion in four unanesthetized, naturally sleeping dogs. The dogs either breathed through a tracheal fistula or through the snout using a fiberglass mask. A total of 295 T and 160 N occlusion tests were performed in SWS and REM sleep. The mean time to arousal during N and T tests was variable in the same dog and among the dogs. The mean time to arousal in SWS-tracheal occlusion was longer than that in N tests in only two of the four dogs. The total number of tests inducing arousal within the first 15 s of SWS-nasal occlusion tests was significantly more than that of T tests (N: 47%; T: 27%). There was a marked depression of arousal within the initial 15 s of REM sleep in T tests compared with N tests (N: 21%; T: 0%). The frequency of early arousals in REM tests was less than that of SWS for both N and T tests. The early arousal in N occlusion is in sharp contrast to the well-described depressed arousal responses to hypoxia, hypercapnia, and asphyxia. This pattern of arousal suggests that the upper airway mechanoreceptors may play an important role in the induction of an early arousal from nasal occlusion.


2007 ◽  
Vol 38 (3) ◽  
pp. 148-154 ◽  
Author(s):  
Veera Eskelinen ◽  
Toomas Uibu ◽  
Sari-Leena Himanen

According to standard sleep stage scoring, sleep EEG is studied from the central area of parietal lobes. However, slow wave sleep (SWS) has been found to be more powerful in frontal areas in healthy subjects. Obstructive sleep apnea syndrome (OSAS) patients often suffer from functional disturbances in prefrontal lobes. We studied the effects of nasal Continuous Positive Airway Pressure (nCPAP) treatment on sleep EEG, and especially on SWS, in left prefrontal and central locations in 12 mild to moderate OSAS patients. Sleep EEG was recorded by polysomnography before treatment and after a 3 month nCPAP treatment period. Recordings were classified into sleep stages. No difference was found in SWS by central sleep stage scoring after the nCPAP treatment period, but in the prefrontal lobe all night S3 sleep stage increased during treatment. Furthermore, prefrontal SWS increased in the second and decreased in the fourth NREM period. There was more SWS in prefrontal areas both before and after nCPAP treatment, and SWS increased significantly more in prefrontal than central areas during treatment. Regarding only central sleep stage scoring, nCPAP treatment did not increase SWS significantly. Frontopolar recording of sleep EEG is useful in addition to central recordings in order to better evaluate the results of nCPAP treatment.


SLEEP ◽  
2019 ◽  
Vol 42 (5) ◽  
Author(s):  
Daniela Grimaldi ◽  
Nelly A Papalambros ◽  
Kathryn J Reid ◽  
Sabra M Abbott ◽  
Roneil G Malkani ◽  
...  

Abstract Slow-wave sleep (SWS) is important for overall health since it affects many physiological processes including cardio-metabolic function. Sleep and autonomic nervous system (ANS) activity are closely coupled at anatomical and physiological levels. Sleep-related changes in autonomic function are likely the main pathway through which SWS affects many systems within the body. There are characteristic changes in ANS activity across sleep stages. Notably, in non-rapid eye-movement sleep, the progression into SWS is characterized by increased parasympathetic activity, an important measure of cardiovascular health. Experimental manipulations that enhance slow-wave activity (SWA, 0.5–4 Hz) can improve sleep-mediated memory and immune function. However, effects of SWA enhancement on autonomic regulation have not been investigated. Here, we employed an adaptive algorithm to deliver 50 ms sounds phase-locked to slow-waves, with regular pauses in stimulation (~5 s ON/~5 s OFF), in healthy young adults. We sought to determine whether acoustic enhancement of SWA altered parasympathetic activity during SWS assessed with heart rate variability (HRV), and evening-to-morning changes in HRV, plasma cortisol, and blood pressure. Stimulation, compared with a sham condition, increased SWA during ON versus OFF intervals. This ON/OFF SWA enhancement was associated with a reduction in evening-to-morning change of cortisol levels and indices of sympathetic activity. Furthermore, the enhancement of SWA in ON intervals during sleep cycles 2–3 was accompanied by an increase in parasympathetic activity (high-frequency, HRV). Together these findings suggest that acoustic enhancement of SWA has a positive effect on autonomic function in sleep. Approaches to strengthen brain–heart interaction during sleep could have important implications for cardiovascular health.


2009 ◽  
Vol 106 (5) ◽  
pp. 1668-1673 ◽  
Author(s):  
Ron Oliven ◽  
Naveh Tov ◽  
Majed Odeh ◽  
Luis Gaitini ◽  
Uri Steinfeld ◽  
...  

Both mandibular advancement (MA) and stimulation of the genioglossus (GG) have been shown to improve upper airway patency, but neither one achieves the effect of continuous positive airway pressure (CPAP) treatment. In the present study we assessed the combined effect of MA and GG stimulation on the relaxed pharynx in patients with obstructive sleep apnea (OSA). We evaluated responses of upper airway pressure-flow relationships and endoscopically determined pharyngeal cross-sectional area to MA and electrical stimulation of the GG in 14 propofol-anesthetized OSA patients. Measurements were undertaken at multiple levels of CPAP, enabling calculation of the critical closing pressure (Pcrit), upstream resistance (Rus), and pharyngeal compliance. GG stimulation, MA, and the combination of both shifted the pressure:flow relationships toward higher flow levels, resulting in progressively lower Pcrit (from baseline of 2.9 ± 2.2 to 0.9 ± 2.5, −1.4 ± 2.9, and −4.2 ± 3.3 cmH2O, respectively), without significant change in Rus. ΔPcrit during GG stimulation was significantly larger during MA than under baseline conditions (−2.8 ± 1.4 vs. −2.0 ± 1.4 cmH2O, P = 0.011). Combining the effect of GG stimulation with MA lowered Pcrit below 0 in all patients and restored pharyngeal patency to a level that enabled flow above the hypopnea level in 10/14 of the patients. Velopharyngeal compliance was not affected by either manipulation. We conclude that the combined effect of MA and GG stimulation is additive and may act in synergy, preventing substantial flow limitation of the relaxed pharynx in most OSA patients.


1982 ◽  
Vol 50 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Wilse B. Webb

The EEG sleep of 5 subjects originally recorded in their early 50s was recorded 15 yr. later in their mid-60s. Increased within-sleep awakenings were present and shorter sleep stages. A modified slow wave scoring system resulted in an increased amount rather than the previously established decline in slow wave sleep with aging. Interpretive cautions necessary in extended-time studies are noted. Reliability of awakening measures across time was seen.


1987 ◽  
Vol 62 (5) ◽  
pp. 2026-2030 ◽  
Author(s):  
C. G. Alex ◽  
R. M. Aronson ◽  
E. Onal ◽  
M. Lopata

To study the effects of continuous positive airway pressure (CPAP) on lung volume, and upper airway and respiratory muscle activity, we quantitated the CPAP-induced changes in diaphragmatic and genioglossal electromyograms, esophageal and transdiaphragmatic pressures (Pes and Pdi), and functional residual capacity (FRC) in six normal awake subjects in the supine position. CPAP resulted in increased FRC, increased peak and rate of rise of diaphragmatic activity (EMGdi and EMGdi/TI), decreased peak genioglossal activity (EMGge), decreased inspiratory time and inspiratory duty cycle (P less than 0.001 for all comparisons). Inspiratory changes in Pes and Pdi, as well as Pes/EMGdi and Pdi/EMGdi also decreased (P less than 0.001 for all comparisons), but mean inspiratory airflow for a given Pes increased (P less than 0.001) on CPAP. The increase in mean inspiratory airflow for a given Pes despite the decrease in upper airway muscle activity suggests that CPAP mechanically splints the upper airway. The changes in EMGge and EMGdi after CPAP application most likely reflect the effects of CPAP and the associated changes in respiratory system mechanics on the afferent input from receptors distributed throughout the intact respiratory system.


1982 ◽  
Vol 53 (4) ◽  
pp. 805-814 ◽  
Author(s):  
S. F. Al-Shway ◽  
J. P. Mortola

Kittens, puppies, cats, and dogs were anesthetized with pentobarbital sodium and tracheotomized. The ventilatory pattern was recorded before, during, and after the delivery of steady flows of room air of 20 or 50 ml X s-1 X kg-1 in the expiratory direction through a cannula inserted just below the larynx. In the newborn, a reduction in breathing frequency, mainly due to a prolongation of the expiratory time, and a decrease in tidal volume contributed to a reduction in minute ventilation particularly with the higher flows; in some instances apnea resulted. Small or no effects were observed in the adult. The ventilatory inhibition was still present when humidified 37 degrees C warmed airstreams were delivered, and it was unchanged when airflows of 4.9% CO21.5% O2–82.6% N2 were applied. After local anesthesia of the laryngeal region or after bypassing the larynx, the ventilatory inhibition disappeared. By closure of a nostril at any given airflow, the upper airway pressure was substantially increased; however, this maneuver did not enhance the respiratory depression. We conclude that airflow through the upper airways can inhibit ventilation in newborn kittens and puppies presumably through the stimulation of airflow-sensitive laryngeal receptors.


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