Arousal responses to hypertension in lambs: effect of sinoaortic denervation

1991 ◽  
Vol 260 (4) ◽  
pp. H1283-H1289 ◽  
Author(s):  
R. S. Horne ◽  
N. D. De Preu ◽  
P. J. Berger ◽  
A. M. Walker

Newborn lambs were subjected to hypertensive stimuli of 1-min duration to examine features of hypertension-induced arousal from sleep. Reflex mechanisms involved were studied by performing the same tests after sinoaortic denervation (SAD). In intact lambs, hypertension increased the probability of arousal from both quiet sleep (QS) and rapid-eye-movement (REM) sleep. Hypertension resulted in arousal in 51% (QS) and 50% (REM) of tests. Arousal time was significantly longer in REM (29.3 +/- 0.9 s, mean +/- SE) than in QS (22.6 +/- 0.6 s, P less than 0.01). Arterial oxygen saturation (So2) and partial pressure of oxygen (Po2) measured at the point of arousal, or after 60 s if arousal failed to occur, were unchanged from control values. After SAD hypertension did not increase the probability of arousal. Arousals significantly decreased (P less than 0.001) to 31% (QS) and 10% (REM). These findings indicate that acute hypertension, mediated via arterial baroreceptors, is a potent stimulus for arousal. In intact lambs, the arousal probability increased and arousal time decreased with increasing stimulus strength (1-30 mmHg), but the arousal time difference between QS and REM remained constant. Consideration of these findings in terms of a simple baroreflex threshold model suggests that the slower response in REM sleep is explained by slower neural processes after the achievement of a critical arousal input rather than by a higher threshold for baroreceptor input in this state.

PEDIATRICS ◽  
1992 ◽  
Vol 89 (5) ◽  
pp. 860-864 ◽  
Author(s):  
Sally L. Davidson Ward ◽  
Daisy B. Bautista ◽  
Thomas C. Keens

Failure to arouse in response to hypoxia has been described in infants at increased risk for sudden infant death syndrome (SIDS) and has been suggested as a possible mechanism for SIDS. However, most SIDS victims are not in a high-risk group before death. Thus, if a hypoxic arousal disorder is an important contributor to SIDS, normal infants might fail to arouse from sleep in response to hypoxia. To test this hypothesis, the authors studied hypoxic arousal responses in 18 healthy term infants younger than 7 months of age (age 12.1 ± 1.7 [SEM] weeks; 56% girls). Hypoxic arousal challenges were performed during quiet sleep by rapidly decreasing inspired oxygen tension (Pio2) to 80 mm Hg for 3 minutes or until arousal (eye opening, agitation, and crying) occurred. Tests were performed in duplicate when possible. Only 8 infants (44%) aroused in response to one or more hypoxic challenges; arousal occurred during 8 (32%) of 25 trials. There were no significant differences in lowest Pio2 or arterial oxygen saturation during hypoxia between those infants who aroused and those who failed to arouse. All 18 infants had a fall in their end-tidal carbon dioxide tension during hypoxia, suggesting that each had a hypoxic ventilatory response despite failure to arouse in the majority. Periodic breathing occurred following hypoxia in only 1 (13%) of the 8 trials that resulted in arousal, compared with 16 (94%) of 17 trials without arousal (P < .005). It is concluded that the majority of normal infants younger than 7 months of age fail to arouse from quiet sleep in response to hypoxia, despite the apparent presence of a hypoxic ventilatory response.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Robert W. Glosemeyer ◽  
Susanne Diekelmann ◽  
Werner Cassel ◽  
Karl Kesper ◽  
Ulrich Koehler ◽  
...  

Abstract Healthy sleep, positive general affect, and the ability to regulate emotional experiences are fundamental for well-being. In contrast, various mental disorders are associated with altered rapid eye movement (REM) sleep, negative affect, and diminished emotion regulation abilities. However, the neural processes mediating the relationship between these different phenomena are still not fully understood. In the present study of 42 healthy volunteers, we investigated the effects of selective REM sleep suppression (REMS) on general affect, as well as on feelings of social exclusion, cognitive reappraisal (CRA) of emotions, and their neural underpinnings. Using functional magnetic resonance imaging we show that, on the morning following sleep suppression, REMS increases general negative affect, enhances amygdala responses and alters its functional connectivity with anterior cingulate cortex during passively experienced experimental social exclusion. However, we did not find effects of REMS on subjective emotional ratings in response to social exclusion, their regulation using CRA, nor on functional amygdala connectivity while participants employed CRA. Our study supports the notion that REM sleep is important for affective processes, but emphasizes the need for future research to systematically investigate how REMS impacts different domains of affective experience and their neural correlates, in both healthy and (sub-)clinical populations.


1992 ◽  
Vol 72 (6) ◽  
pp. 2482-2486 ◽  
Author(s):  
K. J. Barrington ◽  
R. G. Allen

The arousal responses after occlusion of the airway at the mid-trachea were compared with the responses after occlusion of the airway in a face mask in chronically instrumented 3- to 5-day-old piglets. For each site of occlusion arousal latency was significantly longer from active sleep than from quiet sleep. There was a significant increase in the frequency of early arousals after face mask occlusions compared with tracheal occlusions in both sleep states. During quiet sleep the frequency of arousal by 1 s after occlusion was 0.55 with face mask occlusions compared with 0.28 with tracheal occlusion (P less than 0.01). During active sleep the frequency of arousal by 3 s after a face mask occlusion was 0.32 compared with 0.08 after tracheal occlusion (P less than 0.05). Arousal from quiet sleep occurred before changes in arterial oxygen saturation. During active sleep mean saturation at arousal was not different between face mask and tracheal occlusions. Exposure of the upper airway to the pressures generated during airway occlusions results in earlier arousal in both quiet and active sleep, indicating a potential role for upper airway mechanoreceptors in initiating arousal in the newborn piglet.


1999 ◽  
Vol 277 (4) ◽  
pp. R1239-R1245 ◽  
Author(s):  
C. A. Richard ◽  
D. M. Rector ◽  
R. K. Harper ◽  
R. M. Harper

We hypothesized that spontaneous activity declines over widespread areas of the cat ventral medullary surface (VMS) during rapid eye movement (REM) sleep. We assessed neural and hemodynamic activity, measured as changes in reflected 660- and 560-nm wavelength light, from the VMS during sleep and waking states in five adult, unrestrained cats and in two control cats. Relative to quiet sleep, overall activity declined, and variability, assessed by standard deviation, increased by 25% during REM sleep. Variability in activity during waking also increased by 45% over quiet sleep, but mean activity was unchanged. REM sleep onset was preceded by a reduction in the hemodynamic signal from 5 to 60 s before neural activity decline. The activity decline during REM sleep, previously noted in the goat rostral VMS, extends to intermediate VMS areas of the cat and differs from most neural sites, such as the cortex, hippocampus, and thalamus, which increase activity during REM sleep. The activity decline during REM sleep has the potential to modify VMS responsiveness to baroreceptor and chemoreceptor challenges during the REM state.


1979 ◽  
Vol 47 (2) ◽  
pp. 279-284 ◽  
Author(s):  
N. Muller ◽  
G. Volgyesi ◽  
L. Becker ◽  
M. H. Bryan ◽  
A. C. Bryan

It is generally believed that there is a scarcity of muscle spindles in the diaphragm and that there is no tonic activity at end expiration. This conclusion is based mainly on animal studies and the difficulty in differentiating tonic electromyogram activity from noise. We have, however, found a number of muscle spindles in the newborn human diagphragm, concentrated in the region of the central tendon. We also tried to detect tonic activity by decreasing it (by rapid-eye movement (REM) sleep or anesthesia) or increasing it (with abdominal loading). During REM sleep in five infants and five adults, using subcostal electrodes were observed a marked fall in tonic activity (P less than 0.001) compared to non-REM or quiet sleep. We also observed a reduction in diaphragmatic tonic activity with halothane anesthesia (P less than 0.001). With esophageal electrodes in adult subjects, there was a rise in tonic diaphragmatic activity proportional to the amount of abdomina load (P less than 0.001). We conclude that there are muscle spindles in the human diaphragm and that there is tonic activity at end expiration.


PEDIATRICS ◽  
1976 ◽  
Vol 57 (1) ◽  
pp. 142-147
Author(s):  
M. Gabriel ◽  
M. Albani ◽  
F. J. Schulte

The incidence of apneic spells during different sleep states, active sleep, quiet sleep, and undifferentiated sleep was determined in eight preterm infants of 30 to 35 weeks' conceptional age, by means of a polygraphic recording technique. They were free of perinatal and postnatal complications other than apnea. During their active or rapid eye movement (REM) sleep they showed significantly more apneic episodes which were also longer lasting and they were accompanied by bradycardia of a greater severity. The organization of the immature nervous system with a preponderance of inhibitory synaptic connections and the additional inhibition of spinal motoneurons during REM sleep are likely to be the cause of apneic spells in otherwise "normal" preterm infants.


obtaining an exact measurement of oxygen saturation (SpO2) using a finger-probe based pulse oximeter is dependent on both artifact-free infrared (IR) and red (R) Photoplethysmographic signals. However, in actual real-time environment condition, these Photoplethysmographic signals are corrupted due to presence of motion artifact (MA) signal that is produced due to the movement/motion from either hand or finger. To address this motion artifacts interference, the cause of the contamination of Photoplethysmographic signals by the motion artifacts signal is observed using GAIT. Motion and noise artifacts enforce constraints on the usability of the Photoplethysmographic, predominantly in the setting of sleep disorder detection and ambulatory monitoring. Motion and noise artifacts can alter Photoplethysmographic, resulting wrong approximation of physiological factors such as arterial oxygen saturation and heart rate. For overcoming issues and problems, this manuscript presented a new approach for detection of artifacts. First, present an adaptive filter and adaptive threshold model to detect artifact and obtain derivative of correlation coefficient (CC) for labelling artifacts, respectively. Lastly, Improved Support Vector Machine Model is presented to perform classification. Experiment are conducted on real-time dataset. Our approach attain significant performance in term of accuracy, sensitivity, specificity and positive prediction.


PEDIATRICS ◽  
1980 ◽  
Vol 66 (3) ◽  
pp. 425-428
Author(s):  
Peter J. Fleming ◽  
Darlene Cade ◽  
M. Heather Bryan ◽  
A. Charles Bryan

Congenital central hypoventilation (Ondine's curse) is described in an infant with persistant symptoms throughout the first nine months of life. Respiratory control was most severely affected in quiet sleep, although abnormalities were present in rapid eye movement (REM) sleep and while awake. Failure of metabolic control in quiet sleep led to profound hypoventilation. Behavioral or "behavioral-like" inputs in the awake state and REM sleep increased ventilation, but not to expected normal levels. The ventilatory response to inhaled 4% CO2 was markedly depressed in all states.


1995 ◽  
Vol 78 (4) ◽  
pp. 1469-1476 ◽  
Author(s):  
R. C. Basner ◽  
E. Onal ◽  
D. W. Carley ◽  
E. J. Stepanski ◽  
M. Lopata

Six untreated male patients (age 19–55 yr) with obstructive sleep apnea underwent nocturnal polysomnography with acoustic stimulation to determine the effect of transient arousal on obstructive apneas during sleep. Binaural tone bursts (25–95 dB) were delivered in late expiration during the second obstructive apnea of a cycle consisting of four consecutive apneas. For the group, stimulated apneas were significantly shorter (P < 0.05, Fisher's protected least significant difference test) than were the unstimulated apneas when transient electrocortical arousal was elicited in both non-rapid-eye-movement (non-REM) sleep [mean 17 +/- 7 (SD) vs. 26 +/- 9, 23 +/- 10, and 26 +/- 12 s for 2nd vs. 1st, 3rd, and 4th apnea, respectively, of each cycle] and REM sleep (mean 19 +/- 10 vs. 35 +/- 15, 45 +/- 18, and 39 +/- 20 s). Without electrocortical arousal, the stimulated apnea was significantly shortened in non-REM (23 +/- 9 vs. 25 +/- 7, 24 +/- 8, and 26 +/- 8 s) but not in REM (32 +/- 16 vs. 37 +/- 12, 32 +/- 15, and 30 +/- 16 s). Tones delivered relatively early and late in the apnea were equally likely to be associated with resolution of the apnea. The nadir of arterial oxygen saturation of hemoglobin was inversely proportional to apnea length, with higher saturation nadirs associated with the stimulated apneas. These data indicate that transient arousal, induced by nonrespiratory stimulation, influences the resolution of obstructive apneas during sleep.


1982 ◽  
Vol 243 (1) ◽  
pp. R164-R169
Author(s):  
G. G. Haddad ◽  
T. L. Lai ◽  
M. A. Epstein ◽  
R. A. Epstein ◽  
K. F. Yu ◽  
...  

Ventilatory measurements were made noninvasively over 2- to 3-h periods during sleep in each of nine normal infants at 1 mo of age. To assess the changes that occur in ventilation on a breath-to-breath basis, we 1) examined the variations of each of tidal volume (VT), respiratory cycle time (Ttot), expiratory time (TE), and inspiratory time (TI) and 2) studied their interrelationships. We found that the variations of VT, Ttot, and TE but not of TI were significantly greater in rapid-eye-movement (REM) than in quiet sleep. In addition, on a breath-to-breath basis, VT had a positive linear relationship and strong correlation with TI; however, the correlation between VT and TE was weak in both sleep states. VT/Ttot was found to be moderately and negatively correlated with Ttot in both REM and quiet sleep. VT was weakly correlated with Ttot in REM sleep and was, on the average, more correlated with Ttot in quiet sleep. We suggest that in infants 1) on a breath-to-breath basis, VT/Ttot is likely to drop if respiratory frequency is decreased and 2) VT is nonlinearly related to Ttot during sleep; this lack of linearity depends on the lack of constancy of VT/Ttot, which is in turn closely related to the variability of the "on-switching" of inspiratory activity.


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