Slow-wave sleep

About: Slow-wave sleep is a research topic. Over the lifetime, 6543 publications have been published within this topic receiving 320663 citations. The topic is also known as: deep sleep.

Sympathetic muscle nerve activity during sleep in man

Abstract: Muscle sympathetic activity (MSA) was recorded in the peroneal nerve during sleep in 14 sleep-deprived healthy subjects. Continuous noninvasive recordings of finger blood pressure were obtained in 7 subjects. In light sleep (stage 2 sleep) the number of sympathetic bursts/min decreased to 90 +/- 8% (mean +/- SEM) and total MSA (= burst/min x mean burst area) to 89 +/- 5% of the awake value (P less than 0.05, n = 14). In deep sleep (stage 3-4) total MSA decreased further, to 71 +/- 8% of the awake value (n = 5). There was no close correlation between variations of depth of sleep and variations of sympathetic activity but during continuously deepening sleep MSA decreased progressively with time. In stage 2 sleep, high amplitude K complexes were accompanied by short-lasting increases of sympathetic activity. Since these increases of MSA were not preceded by decreases of diastolic blood pressure, which is known to evoke increased sympathetic nerve traffic in muscle nerves, we suggest that K complex related increases of MSA are signs of arousal which elicit both cortical EEG phenomena and activation of cerebral sympathetic centres. During desynchronized (REM) sleep, total MSA increased to 124 +/- 12% of the value in awake state (n = 5). The increases occurred mainly in short irregular periods, often related to rapid eye movements and there was an inverse relationship between the duration of the desynchronized sleep and the increase of total MSA. Our findings are similar to the data obtained in animal experiments and may partly explain changes of blood pressure during synchronized and desynchronized sleep reported previously in man.

Why We Sleep: The Functions of Sleep in Humans and Other Mammals

Abstract: Sleep deprivation physiological effects of sleep deprivation body restitution and sleep waking awareness, subsequent sleep and cerebral restitution core and optical sleep sleep in other mammals REM sleep.

Genetic determinants of sleep regulation in inbred mice.

Abstract: Genetic variation in the expression and regulation of sleep was assessed in six inbred mice strains (AK, C, B6, BR, D2, 129). The amount, distribution, and fragmentation of the behavioral states wakefulness (W), slow-wave sleep (SWS), and paradoxical sleep (PS), as well as EEG delta power in SWS, were determined and compared among strains and between baseline and recovery from a 6-hour sleep deprivation (SD) starting at lights-on. In baseline, the most striking strain differences concerned sleep amount, the onset and duration of the main rest period, and SWS fragmentation. The time course of delta power in SWS during the main rest period was similar between strains. Immediately following the SD, high delta power values were reached (higher for AK than for 129). However, the relative increase in delta power, compared to the first 6 hours of the baseline rest period, was not strain-specific. Over the first 6 hours of recovery, W was decreased and PS increased in AK, B6, BR, and 129. In C and D2, time spent in any of the states was not affected by the SD. In contrast, in the recovery dark period, SWS and PS were invariably increased. In recovery, SWS fragmentation was strongly reduced for D2, resulting in the disappearance of the strain differences observed in baseline. Since these inbred strains are fully homozygous and thus can be considered genetic clones, the sleep-related strain differences reported here can be attributed to differences in genotype. Therefore, this study provides a basis for the identification of genetic factors underlying sleep and its regulation.

Alcohol and sleep I: effects on normal sleep.

Abstract: This review provides a qualitative assessment of all known scientific studies on the impact of alcohol ingestion on nocturnal sleep in healthy volunteers. At all dosages, alcohol causes a reduction in sleep onset latency, a more consolidated first half sleep and an increase in sleep disruption in the second half of sleep. The effects on rapid eye movement (REM) sleep in the first half of sleep appear to be dose related with low and moderate doses showing no clear trend on REM sleep in the first half of the night whereas at high doses, REM sleep reduction in the first part of sleep is significant. Total night REM sleep percentage is decreased in the majority of studies at moderate and high doses with no clear trend apparent at low doses. The onset of the first REM sleep period is significantly delayed at all doses and appears to be the most recognizable effect of alcohol on REM sleep followed by the reduction in total night REM sleep. The majority of studies, across dose, age and gender, confirm an increase in slow wave sleep (SWS) in the first half of the night relative to baseline values. The impact of alcohol on SWS in the first half of night appears to be more robust than the effect on REM sleep and does not appear to be an epiphenomenon REM sleep reduction. Total night SWS is increased at high alcohol doses across gender and age groups.

Alpha sleep characteristics in fibromyalgia

Abstract: Objective To characterize the patterns of alpha electroencephalographic sleep and their associations with pain and sleep in patients with fibromyalgia. Methods Pain and sleep symptoms of 40 female patients with fibromyalgia and 43 healthy control subjects were studied before and after overnight polysomnography. Blinded analyses of alpha activity in non–rapid eye movement (non-REM) sleep were performed using time domain, frequency domain, and visual analysis techniques. Results Three distinct patterns of alpha sleep activity were detected in fibromyalgia: phasic alpha (simultaneous with delta activity) in 50% of patients, tonic alpha (continuous throughout non-REM sleep) in 20% of patients, and low alpha activity in the remaining 30% of patients. Low alpha activity was exhibited by 83.7% of control subjects (P < 0.01). All fibromyalgia patients who displayed phasic alpha sleep, activity reported worsening of pain after sleep, compared with 58.3% of patients with low alpha activity (P < 0.01) and 25.0% of patients with tonic alpha activity (P < 0.01). Postsleep increase in the number of tender points occurred in 90.0% of patients with phasic alpha activity, 41.7% of patients with low alpha activity, and 25.0% of patients with tonic alpha activity (P < 0.01). Self ratings of poor sleep were reported by all patients with phasic alpha activity, 58.3% of patients with low alpha activity (P < 0.01), and 12.5% of patients with tonic alpha activity (P < 0.01). Patients with phasic alpha activity reported longer duration of pain than patients in other subgroups (P < 0.01). Additionally, patients with phasic alpha sleep activity exhibited less total sleep time than patients in other subgroups (P < 0.05), as well as lower sleep efficiency (P < 0.05) and less slow wave sleep (P < 0.05) than patients with a tonic alpha sleep pattern. Conclusion Alpha intrusion during sleep can be of different patterns. Phasic alpha sleep activity was the pattern that correlated better with clinical manifestations of fibromyalgia.