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Sleep States (sleep + states)
Selected AbstractsThe sleep of co-sleeping infants when they are not co-sleeping: Evidence that co-sleeping is stressfulDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2002Melissa Hunsley Abstract Co-sleeping proponents consider the practice to be "natural" and a potential protection against sudden infant death syndrome (SIDS); others consider the practice of an infant sleeping in the parents' bed for prolonged periods at night to place an infant at risk for harm or death. For this study, co-sleeping was investigated from a different perspective, that is, as a significant early experience to investigate as it may have implications for the infant's development. The sleep of 101 normal, full-term infants was recorded nonintrusively in the home for 24 hr periods when they were 5 weeks and 6 months old. Infants were assigned to three groups: short-term co-sleepers, long-term co-sleepers, and non-co-sleepers. Their sleep states and wakefulness were compared at the two ages and over age. At 5 weeks and 6 months, the long-term co-sleeping infants differed significantly from the non-co-sleepers on a number of measures: At 5 weeks, they showed more quiet sleep and longer bouts of quiet sleep; and at 6 months, they also showed less active sleep, fewer arousals in active sleep, and less wakefulness. Each of these differences indicates a markedly lower arousal level in the long-term co-sleeping infants. This sleep pattern has been repeatedly found to be an indicator of stress. We infer that a major source of stress for these infants is the experience of sleep disturbance documented for infants when they were co-sleeping. Based on extensive evidence for long-term effects of early stress, we conclude that co-sleeping should have significant implications for infants' neurobehavioral development. © 2002 John Wiley & Sons, Inc. Dev Psychobiol 40: 14,22, 2002 [source] Human fetal and neonatal movement patterns: Gender differences and fetal-to-neonatal continuityDEVELOPMENTAL PSYCHOBIOLOGY, Issue 4 2001C. Robert Almli Abstract Longitudinal quantification of leg movements per minute for human subjects during both fetal and neonatal periods was accomplished from videotapings conducted antenatally (ultrasonography 30, 34, and 37 weeks gestational age) and postnatally (birth and 6 weeks of age). Fetal/neonatal subjects displayed decreasing numbers of leg movements per minute during antenatal development (30 to 37 weeks), followed by increasing numbers of leg movements per minute during postnatal development (birth to 6 weeks of age). Male subjects displayed greater numbers of leg movements per minute than female subjects during both antenatal and postnatal development. Fetal-to-neonatal continuity for numbers of leg movements per minute was found for comparisons between fetal (37 weeks gestational age) and neonatal (during sleep states at birth) measures, and females displayed a stronger and different movement continuity pattern than males. These results indicate a differential time course for neurobehavioral development of male and female fetuses/neonates, and the findings have implications for the clinical assessment of fetal neurobehavioral development and well-being. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 38: 252,273, 2001 [source] Vagus Nerve Stimulation Therapy Induces Changes in Heart Rate of Children during SleepEPILEPSIA, Issue 5 2007Boubker Zaaimi Summary:,Purpose: This study analyzed changes in the heart rates of children receiving vagus nerve stimulation (VNS) therapy for pharmacoresistant epilepsy. Methods: Changes in the heart rates of ten children receiving VNS therapy for pharmacoresistant epilepsy were evaluated with polysomnographic recordings, including electrocardiogram (ECG), EEG, thoraco-abdominal distension, nasal airflow, and VNS artifacts. Measurements during stimulation were compared with those at baseline for each patient. Result: While the VNS therapy pulse generator was delivering stimulation, the heart rates of four children increased significantly (p < 0.01), decreased for one child, and increased at the end of the stimulation for one child. The heart rates of four children did not change. Changes in heart rate varied during VNS, within stimulation cycles for individual children and from one child to another. Changes in heart rate differed between rapid eye movement (REM) and non-REM (NREM) sleep states. Respiratory changes (increases in frequency and decreases in amplitude) were concomitant with the changes in heart rate. Conclusion: In this case series of children with pharmacoresistant epilepsy, cardiorespiratory variations occurred while the VNS therapy pulse generator was delivering stimulation. Understanding these variations may allow further optimization of VNS parameters. [source] Dynamic power management in new architecture of wireless sensor networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6 2009Chuan Lin Abstract Dynamic power management (DPM) technology has been widely used in sensor networks. Though many specific technical challenges remain and deserve much further study, the primary factor currently limiting progress in sensor networks is not these challenges but is instead the lack of an overall sensor network architecture. In this paper, we first develop a new architecture of sensor networks. Then we modify the sleep state policy developed by Sinha and Chandrakasan in (IEEE Design Test Comput. 2001; 18(2):62,74) and deduce that a new threshold satisfies the sleep-state transition policy. Under this new architecture, nodes in deeper sleep states consume lower energy while asleep, but require longer delays and higher latency costs to awaken. Implementing DPM with considering the battery status and probability of event generation will reduce the energy consumption and prolong the whole lifetime of the sensor networks. We also propose a new energy-efficient DPM, which is a modified sleep state policy and combined with optimal geographical density control (OGDC) (Wireless Ad Hoc Sensor Networks 2005; 1(1,2):89,123) to keep a minimal number of sensor nodes in the active mode in wireless sensor networks. Implementing dynamic power management with considering the battery status, probability of event generation and OGDC will reduce the energy consumption and prolong the whole lifetime of the sensor networks. Copyright © 2008 John Wiley & Sons, Ltd. [source] Disruptions in Sleep Time and Sleep Architecture in a Mouse Model of Repeated Ethanol WithdrawalALCOHOLISM, Issue 7 2006Lynn M. Veatch Background: Insomnia and other sleep difficulties are perhaps the most common and enduring symptoms reported by alcoholics undergoing detoxification, especially those alcoholics with a history of multiple detoxifications. While some studies have reported sleep disruptions in animal models after chronic ethanol exposure, the reports are inconsistent and few address sleep architecture across repeated ethanol exposures and withdrawals. The present study evaluated sleep time and architecture in a well-characterized mouse model of repeated chronic ethanol exposure and withdrawal. Methods: C57BL6/J mice were fitted with electrodes in frontal cortex, hippocampus, and nuchal muscle for collection of continuous electroencephalogram (EEG)/electromyogram (EMG) data. Baseline data were collected, after which mice received 4 cycles of 16-hour exposure to alcohol (ethanol: EtOH) vapor separated by 8-hour periods of withdrawal or similar handling in the absence of EtOH vapor. Ethanol-exposed mice attained a blood ethanol concentration of 165 mg%. Upon completion of vapor exposure, EEG/EMG data were again collected across 4 days of acute withdrawal. Data were subjected to automated analyses classifying 10-second epochs into wake, non,rapid eye movement (REM) sleep, or REM sleep states. Results: Mice in withdrawal after chronic EtOH exposure showed profound disruptions in the total time asleep, across the acute withdrawal period. Sleep architecture, the composition of sleep, was also disrupted with a reduction in non-REM sleep concomitant with a profound increase in REM sleep. While altered sleep time and non-REM sleep loss resolved by the fourth day of withdrawal, the increase in REM sleep ("REM rebound") persisted. Conclusions: These results mirror those reported for the human alcoholic and demonstrate that EtOH withdrawal,induced sleep disruptions are evident in this mouse model of alcohol withdrawal,induced sensitization. This mouse model may provide mechanisms to investigate fully the high correlation between unremitting sleep problems and increased risk of relapse documented clinically. [source] Effects of antenatal magnesium sulfate and corticosteroid therapy on sleep states of preterm infants,RESEARCH IN NURSING & HEALTH, Issue 4 2006Beth Black Abstract This exploratory longitudinal study was designed to compare the neonatal illness severity, sleep,wake, and respiratory sleep behaviors of preterm infants whose mothers received prenatal corticosteroids and/or magnesium sulfate (MgSO4) with those of infants whose mothers did not receive these medications. The 134 infants were divided into four groups: those whose mothers received MgSO4 only, those who received steroids only, those who received both MgSO4 and steroids, and those who received neither. The groups did not differ on infant characteristics or illness severity. Infants exposed to MgSO4 had more active sleep without rapid eye movement, indicating poorly organized active sleep. The MgSO4 -only group had higher quiet sleep regularity scores and fewer state changes. These findings suggest that fetal exposure to MgSO4 may subtly affect the central nervous system. © 2006 Wiley Periodicals, Inc. Res Nurs Health 29: 269,280, 2006 [source] Selective enhancement of rapid eye movement sleep by deep brain stimulation of the human pons,ANNALS OF NEUROLOGY, Issue 1 2009Andrew S. Lim MD Animal studies suggest that rapid eye movement (REM) sleep is governed by the interaction of REM-promoting and REM-inhibiting nuclei in the pontomesencephalic tegmentum. The pedunculopontine nucleus is proposed to be REM promoting. Using polysomnography, we studied sleep in five parkinsonian patients undergoing unilateral pedunculopontine nucleus deep brain stimulation (DBS). We demonstrated a near doubling of nocturnal REM sleep between the DBS "off" and DBS "on" states, without significant changes in other sleep states. This represents the first demonstration that DBS can selectively modulate human sleep, and it supports an important role for the pedunculopontine nucleus region in modulating human REM sleep. Ann Neurol 2009;66:110,114 [source] Nicotine in breast milk influences heart rate variability in the infantACTA PAEDIATRICA, Issue 8 2008Anders Dahlström Abstract Aim: To study the effects of postnatal exposure to nicotine on the regulation of heart rate and blood pressure in infants. Subjects and Methods: Thirty-eight mother,infant pairs were studied. Twenty nonsmoking and 18 smoking (2,20 cigarettes per day) mothers were included. All infants were healthy, exclusively breastfed and their postnatal age was 6 weeks. During a home visit infant's urine and mothers' milk were sampled and concentrations of nicotine and cotinine were analyzed. Infants' electrocardiogram (ECG) were recorded, sleep state documented and blood pressure during sleep was measured. Heart rate variability (HRV) was calculated with spectral analysis of R,R intervals. Results: The smoking mothers exposed their infants to nicotine in milk with a median nicotine concentration of 47 (8,192) ,g/L. Analysis of infants' urine showed that the nonsmoking group had 0.8 (0,5.2) and the smoke group 60 (17,139) ,g cotinine/L (p < 0.01). The frequency domain low-to-high frequency (LF/HF) ratio, was correlated to milk nicotine concentrations in the milk sample, from smoking mothers. HRV decreased, with increasing milk nicotine, ingested by the boys (r =,0.74, p = 0.02) but not the girls (r =,0.13, p = 0.76). The differences of mean arterial pressure between sleep states in the infants, were significantly lower in the smoke group 5.8(6.8) compared to the nonsmoke group 11.5(7.2) mmHg (p = 0.03). Conclusions: Postnatal exposure to nicotine influences autonomic cardiovascular control in infants. [source] PHYSIOLOGICAL SLEEP-DEPENDENT CHANGES IN ARTERIAL BLOOD PRESSURE: CENTRAL AUTONOMIC COMMANDS AND BAROREFLEX CONTROLCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2008Alessandro Silvani SUMMARY 1Sleep is a heterogeneous behaviour. As a first approximation, it is subdivided objectively into two states: non-rapid eye movement sleep (NREMS) and rapid eye movement sleep (REMS). 2The mean value and variability of arterial blood pressure (ABP) decrease physiologically from wakefulness to NREMS. In REMS, there may be a further decrease or increase in mean ABP as well as phasic hypertensive events, which enhance the variability of ABP. 3The reduced mean ABP during NREMS results from a decrease in either heart rate or sympathetic vasoconstrictor tone. During REMS, sympathetic activity to the different cardiovascular effectors undergoes a substantial repatterning. Thus, the mean ABP in REMS reflects a balance between changes in cardiac output and constriction or dilatation of different vascular beds. 4In both sleep states, the phasic changes in ABP are driven by bursts of vasoconstriction, which may be accompanied by surges of heart rate. 5The available evidence supports the hypothesis that the sleep-dependent changes in ABP, either tonic or phasic, result from the integration between cardiovascular reflexes and central autonomic commands that are specific to each sleep state. [source] | ||||||||||