Repetitive hypoxia rapidly depresses cardio-respiratory responses during active sleep but not quiet sleep in the newborn lamb

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.

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Direct measurement of the energy expenditure of physical activity in preterm infants

Journal of Applied Physiology ◽

10.1152/jappl.1998.85.1.223 ◽

1998 ◽

Vol 85 (1) ◽

pp. 223-230 ◽

Cited By ~ 30

Author(s):

Patti J. Thureen ◽

Robert E. Phillips ◽

Karen A. Baron ◽

Mark P. DeMarie ◽

William W. Hay

Keyword(s):

Physical Activity ◽

Energy Expenditure ◽

Preterm Infants ◽

Direct Measurement ◽

Muscle Activity ◽

Energy Cost ◽

Force Plate ◽

Total Energy Expenditure ◽

Active Sleep ◽

Quiet Sleep

The energy cost of physical activity (EEA) has been estimated to account for 5–17% of total energy expenditure (TEE) in neonates. To directly measure EEA, a force plate was developed and validated to measure work outputs ranging from 0.3 to 40 kcal ⋅ kg−1 ⋅ day−1. By use of this force plate plus indirect calorimetry, TEE and EEA were measured and correlated with five activity states in 24 infants with gestational age of 31.6 ± 0.5 (SE) wk and postnatal age of 24.8 ± 3.7 days. TEE and EEA were 69.2 ± 1.5 and 2.4 ± 0.2 kcal ⋅ kg−1 ⋅ day−1, respectively. EEA per state was 0.5 ± 0.0 (quiet sleep), 2.4 ± 0.2 (active sleep), 2.8 ± 0.4 (quiet awake), 7.5 ± 0.8 (active awake), and 15.1 ± 2.3 (crying) kcal ⋅ kg−1 ⋅ day−1. This provides the first direct measurement of the contribution of physical activity to TEE in preterm infants and will enable measurement of caloric expenditure from muscle activity in various disease conditions and development of nursing strategies to minimize unnecessary energy losses.

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Arousal pattern following central and obstructive breathing abnormalities in infants and children

Journal of Applied Physiology ◽

10.1152/jappl.1996.81.6.2651 ◽

1996 ◽

Vol 81 (6) ◽

pp. 2651-2657 ◽

Cited By ~ 130

Author(s):

Frances McNamara ◽

Faiq G. Issa ◽

Colin E. Sullivan

Keyword(s):

Obstructive Sleep Apnea ◽

Pediatric Population ◽

Infants And Children ◽

Clinical Severity ◽

Rapid Eye Movement Sleep ◽

Active Sleep ◽

Quiet Sleep ◽

Respiratory Events ◽

Obstructive Sleep ◽

In Infants And Children

McNamara, Frances, Faiq G. Issa, and Colin E. Sullivan.Arousal pattern following central and obstructive breathing abnormalities in infants and children. J. Appl. Physiol. 81(6): 2651–2657, 1996.—We analyzed the polysomnographic records of 15 children and 20 infants with obstructive sleep apnea (OSA) to examine the interaction between central and obstructive breathing abnormalities and arousal from sleep. Each patient was matched for age with an infant or child who had no OSA. We found that the majority of respiratory events in infants and children was not terminated with arousal. In children, arousals terminated 39.3 ± 7.2% of respiratory events during quiet sleep and 37.8 ± 7.2% of events during active (rapid-eye-movement) sleep. In infants, arousals terminated 7.9 ± 1.0% of events during quiet sleep and 7.9 ± 1.2% of events during active sleep. In both infants and children, however, respiratory-related arousals occurred more frequently after obstructive apneas and hypopneas than after central events. Spontaneous arousals occurred in all patients with OSA during quiet and active sleep. The frequency of spontaneous arousals was not different between children with OSA and their matched controls. During active sleep, however, infants with OSA had significantly fewer spontaneous arousals than did control infants. We conclude that arousal is not an important mechanism in the termination of respiratory events in infants and children and that electroencephalographic criteria are not essential to determine the clinical severity of OSA in the pediatric population.

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Postnatal maturation of laryngeal chemoreflexes in the preterm lamb

Journal of Applied Physiology ◽

10.1152/japplphysiol.00977.2006 ◽

2007 ◽

Vol 102 (4) ◽

pp. 1429-1438 ◽

Cited By ~ 29

Author(s):

Marie St-Hilaire ◽

Nathalie Samson ◽

Elise Nsegbe ◽

Charles Duvareille ◽

François Moreau-Bussière ◽

...

Keyword(s):

Heart Rate ◽

Lower Airway ◽

Distilled Water ◽

Active Sleep ◽

Sleep State ◽

Quiet Sleep ◽

General Belief ◽

Postnatal Maturation ◽

Laryngeal Mucosa ◽

Life Threatening

Laryngeal chemoreflexes (LCR) are triggered by the contact of liquids with the laryngeal mucosa. In the mature organism, LCR trigger lower airway protective responses (coughing, effective swallowing, and arousal) to prevent aspiration. General belief holds that LCR are responsible for apnea and bradycardia in the newborn mammal, including humans. Our laboratory has recently shown that LCR in full-term lambs are consistently analogous to the mature LCR reported in adult mammals, without significant apneas and bradycardias (St-Hilaire M, Nsegbe E, Gagnon-Gervais K, Samson N, Moreau-Bussiere F, Fortier PH, and Praud J-P. J Appl Physiol 98: 2197–2203, 2005). The aim of the present study was to assess LCR in nonsedated, newborn preterm lambs born at 132 days of gestation (term = 147 days). The preterm lambs were instrumented for recording glottal adductor electromyogram, electroencephalogram, eye movements, heart rate, respiration, and oximetry. A chronic supraglottal catheter was used for injecting 0.5 ml of saline, distilled water, and HCl (pH 2) during quiet sleep, active sleep, and wakefulness on postnatal days 7 (D7) and 14 (D14). Laryngeal stimulation by water or HCl on D7 induced significant apneas, bradycardia, and desaturation, which, at times, appeared potentially life-threatening. No significant apneas, bradycardias, or desaturation were observed on D14. No consistent effects of sleep state could be shown in the present study. In conclusion, laryngeal stimulation by liquids triggers potentially dangerous LCR in preterm lambs on D7, but not on D14. It is proposed that maturation of the LCR between D7 and D14 is partly involved in the disappearance of apneas/bradycardias of prematurity with postnatal age.

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SLEEP CYCLE CHARACTERISTICS IN INFANTS

PEDIATRICS ◽

10.1542/peds.43.1.65 ◽

1969 ◽

Vol 43 (1) ◽

pp. 65-70

Author(s):

Evelyn Stern ◽

Arthur H. Parmelee ◽

Yoshio Akiyama ◽

Marvin A. Schultz ◽

Waldemar H. Wenner

Keyword(s):

Cycle Length ◽

Activity Cycle ◽

Sleep Cycle ◽

Normal Brain ◽

Active Sleep ◽

Quiet Sleep ◽

Activity Cycles ◽

Significant Measure ◽

Polygraphic Recording ◽

Rest Activity

Within the sleep of adults and infants there are cyclic fluctuations between quiet and active sleep. These fluctuations may also persist during wakefulness as rest-activity cycles but are less readily detected. They constitute a fundamental biological rhythm on which other daily rhythms are superimposed. In adults the rest-activity cycle is 90 minutes in duration. The quiet-active sleep cycles of term, 3-, and 8-month-old infants were determined by polygraphic recording of eye and body movements, respirations, and electroencephalogram. The cycle length at term was 47 minutes and 49 and 50 minutes at 3 and 8 months. The increase in cycle length with maturation was not significant, but there was a significant change in the proportion of quiet to active sleep within a cycle. At term they were equal, while at 8 months quiet sleep was twice as long as active sleep. Quiet sleep is a highly controlled state requiring complex feedback mechanisms. The increasing proportion of quiet sleep may be a significant measure of normal brain development.

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Periodic Apnea in the Full-Term Infant: Individual Consistency, Sex Differences, and State Specificity

PEDIATRICS ◽

10.1542/peds.70.1.79 ◽

1982 ◽

Vol 70 (1) ◽

pp. 79-86

Author(s):

Stephen P. Waite ◽

Evelyn B. Thoman

Keyword(s):

Periodic Breathing ◽

Term Infant ◽

Full Term ◽

Respiratory Pattern ◽

Active Sleep ◽

Sleep State ◽

Quiet Sleep ◽

Term Infants ◽

The Mean ◽

Individual Consistency

The occurrence of periodic apnea (apnea during periodic breathing) was studied in 27 normal, full-term infants during the first five weeks of life. The rate and mean length of apnea were analyzed both with respect to sleep state and with respect to respiratory pattern, ie, periodic vs nonperiodic breathing. The rate of apnea was found to vary according to sleep state and the pattern of breathing. The highest apnea rates were non-periodic apneas in active sleep. Periodic apnea rates were relatively low in both active and quiet sleep; however, this type of apnea was consistently observed from weeks 2 through 5. The proportion of apneas that are periodic is much higher in quiet sleep than in active sleep. Rates of periodic and nonperiodic apnea were more consistently correlated in active sleep than in quiet sleep. The mean length of periodic apnea was found to be significantly greater than the mean length of nonperiodic apnea in both sleep states, a difference that reflected a greater positive skew in the distribution of the nonperiodic apnea lengths. This variation in length between periodic and nonperiodic apnea explains, in part, the increased mean length in quiet sleep compared with active sleep. There were significant individual differences over weeks in both forms of apnea in active sleep and in quiet sleep. Female infants were observed to have higher rates of nonperiodic apnea than male infants in active sleep, although no significant differences in the distribution of lengths were obtained.

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Apneic Spells and Sleep States in Preterm Infants

PEDIATRICS ◽

10.1542/peds.57.1.142 ◽

1976 ◽

Vol 57 (1) ◽

pp. 142-147

Author(s):

M. Gabriel ◽

M. Albani ◽

F. J. Schulte

Keyword(s):

Nervous System ◽

Eye Movement ◽

Preterm Infants ◽

Rem Sleep ◽

Synaptic Connections ◽

Spinal Motoneurons ◽

Active Sleep ◽

Quiet Sleep ◽

Recording Technique ◽

Polygraphic Recording

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.

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Development of autonomic heart rate control in the kitten during sleep

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1980.238.6.h829 ◽

1980 ◽

Vol 238 (6) ◽

pp. H829-H835

Author(s):

J. R. Egbert ◽

P. G. Katona

Keyword(s):

Heart Rate ◽

Rate Control ◽

Intrinsic Rate ◽

Blocking Agent ◽

Heart Rate Change ◽

Heart Rate Control ◽

Active Sleep ◽

Quiet Sleep ◽

Human Infants ◽

Sympathetic Control

Development of cardiac rate control was studied in 34 kittens aged 4 days to 6 wk during quiet and active sleep, using atropine and propranolol to quantitatively assess the degree of tonic parasympathetic and sympathetic control, with the analysis based on the Rosenblueth and Simeone model. The order of blocking agent administration did not significantly affect the results if a correction was made for the baroreceptor-mediated heart rate change after the blockade of a single autonomic branch. During the first 4 wk, the heart rate in quiet sleep was lower than in active sleep due to a significantly higher parasympathetic tone. The heart rate decreased with age in both sleep states: the decrease in quiet sleep was accompanied by a transition from sympathetic to parasympathetic dominance. The intrinsic rate of the pharmacologically denervated heart was maximum at about 2 wk and decreased steadily thereafter. The observed changes may help explain some features of the development in heart rate previously reported for sleeping human infants.

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Enhancement of quiet sleep in rabbit neonates by muramyl dipeptide

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1987.253.4.r646 ◽

1987 ◽

Vol 253 (4) ◽

pp. R646-R654 ◽

Cited By ~ 4

Author(s):

D. Davenne ◽

J. M. Krueger

Keyword(s):

Slow Wave ◽

Slow Wave Sleep ◽

Muramyl Dipeptide ◽

Wave Activity ◽

Synthetic Analogue ◽

Active Sleep ◽

Quiet Sleep ◽

Delta Wave ◽

Parallel Increase ◽

Behavioral Criteria

Muramyl peptides that induce excess slow-wave sleep have been isolated from urine and brain. A synthetic analogue to those substances, muramyl dipeptide (MDP, N-acetylmuramyl-L-alanyl-D-isoglutamine), was found to induce prolonged increases in slow-wave sleep and to increase electroencephalographic (EEG) delta-wave activity. MDP is also pyrogenic, although this activity can be separated from its somnogenic activity. To further investigate the somnogenic actions of MDP, neonatal rabbits were used in the present study. Intraperitoneal injection of 100 micrograms/kg MDP induced differential somnogenic and pyrogenic effects; from postnatal days 7-9, MDP increased duration of quiet sleep (QS, the precursor of adult slow-wave sleep) and decreased active sleep (AS) as judged by behavioral criteria. These animals were not febrile during the period of enhanced QS, nor did MDP alter EEG delta-wave activity at this age. From postnatal days 10-15, MDP induced prolonged (6 h) increases in duration of QS; both behavioral and EEG criteria were used at this age to determine duration of QS and AS. Maximum MDP-induced effects occurred during the 2nd h, with a parallel increase in amplitudes of EEG delta-wave activity. At this age, MDP also elicited monophasic fevers and inhibition of AS, with maximum effects observed during hours 3-4 postinjection. After postnatal day 16, MDP-induced somnogenic and febrile responses were similar to those observed in adult rabbits. We conclude that the mechanisms responsible for behavioral sleep states are responsive to a sleep-promoting substance early in ontogenesis.

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PGO-related potentials in lumbar motoneurons during active sleep

Journal of Neurophysiology ◽

10.1152/jn.1992.68.1.109 ◽

1992 ◽

Vol 68 (1) ◽

pp. 109-116 ◽

Cited By ~ 25

Author(s):

F. Lopez-Rodriguez ◽

M. H. Chase ◽

F. R. Morales

Keyword(s):

Spinal Cord ◽

Membrane Potential ◽

Transition Period ◽

Present Report ◽

Active Sleep ◽

Quiet Sleep ◽

Inhibitory Postsynaptic Potentials ◽

Related Potentials ◽

The Relationship ◽

Pgo Waves

1. The present report describes the relationship that occurs during active sleep between ponto-geniculo-occipital (PGO) waves and changes in spinal cord motoneuron membrane potential. 2. These changes were characterized by the appearance of a complex pattern of motoneuron hyperpolarizing potentials, with a duration of approximately 300 ms, that were centered around the PGO wave. The first hyperpolarizing potential began before the onset of the PGO wave. Emerging from this hyperpolarizing potential was a second, larger-amplitude hyperpolarizing potential; it was followed by a succession of smaller-amplitude hyperpolarizations. 3. All potentials were present in conjunction with PGO waves during active sleep, but they were observed only in some motoneurons when PGO waves occurred during the transition period from quiet sleep to active sleep. 4. The potentials were reversed by chloride, demonstrating that they were inhibitory postsynaptic potentials (IPSPs). 5. These data, combined with the fact that these PGO-related IPSPs are blocked by strychnine, support the hypothesis that they are the result of the phasic enhancement of the activity of the same system that inhibits motoneurons during active sleep.

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