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.

High nocturnal body temperatures and disturbed sleep in women with primary dysmenorrhea.

Abstract: Primary dysmenorrhea is characterized by painful uterine cramps, near and during menstruation, that have an impact on personal life and productivity. The effect on sleep of this recurring pain has not been established. We compared sleep, nocturnal body temperatures, and hormone profiles during the menstrual cycle of 10 young women who suffered from primary dysmenorrhea, without any menstrual-associated mood disturbances, and 8 women who had normal menstrual cycles. Dysmenorrheic pain significantly decreased subjective sleep quality, sleep efficiency, and rapid eye movement (REM) sleep but not slow wave sleep (SWS), compared with pain-free phases of the menstrual cycle and compared with the controls. Even before menstruation, in the absence of pain, the women with dysmenorrhea had different sleep patterns, nocturnal body temperatures, and hormone levels compared with the controls. In the mid-follicular, mid-luteal, and menstrual phases, the dysmenorrheics had elevated morning estrogen concentrations, higher mean in-bed temperatures, and less REM sleep compared with the controls, as well as higher luteal phase prolactin levels. Both groups of women had less REM sleep when their body temperatures were high during the luteal and menstrual phases, implying that REM sleep is sensitive to elevated body temperatures. We have shown that dysmenorrhea is not only a disorder of menstruation but is manifest throughout the menstrual cycle. Furthermore, dysmenorrheic pain disturbs sleep, which may exacerbate the effect of the pain on daytime functioning.

The role of slow wave sleep in memory processing.

Abstract: ability to form and retain nonemotional, fact-based (“episodic”) memories has been linked to the presence and integrity of slow wave sleep (SWS). Compared with healthy control subjects, patients with primary insomnia have diminished amounts of SWS, and this has been significantly correlated with reduced memory consolidation. 7 Similarly, increasing age (> 30 years old) is associated with diminished levels of classically scored SWS, which is associated with a decline in sleep-related memory consolidation. 9

Hierarchy of micro-arousals and the microstructure of sleep

Abstract: This review is aimed at providing an overview concerning the hierarchy of different kinds of micro-arousals (without awakening) during slow wave sleep (SWS), and to summarize available data on the dynamic interplay of phasic events constituting the microstructural web of sleep EEG. K-complexes are considered elementary forms of arousal during SWS. They carry characteristics of evoked potentials, which provide subattentive information processing and have at the same time level-setting sleep maintenance functions. Micro-arousals are more complex arousal-dependent phasic events in the hierarchy. One class of recurring micro-arousals are preceded by K-complexes, while others, such as phases of spontaneous transitory activation--type micro-arousals-- represent higher levels of arousal, and are associated with EEG desyncronization, increased muscle activity and signs of autonomous arousal. All types of micro-arousals function in a complex interrelationship with another phasic event--sleep spindles--interpreted as microstates inhibiting sensory inflow through the thalamic relay system. Lastly the CAP (cyclic alternating pattern) phenomenon offers a global framework for characterizing and measuring arousal instability. Appearance of CAP sequences reflects arousal instability in a higher duration range than individual micro-arousals. They represent an arousal control mechanism reflecting that all arousing influences set into motion an oscillatory level setting system around the referential state providing a flexible adaptation for the system to defend it against perturbations. The whole arousal (without awakening) hierarchy thus seems to play an essential role in sleep regulation, serving both cyclicity and maintenance of sleep and providing at the same time flexible contact between sleeper and environment--preserving the possibility to wake up in case of any biological danger, and tailoring sleep program according to actual environmental or inner demands. Although at present there are no accepted rules for microstructural evaluation of sleep, microstructural aspects provide a more dynamic picture both about the preprogrammed and reactive changes in sleep. This approach gives us some clues to better understand sleep disorders as well. Several studies concerning microstructural analysis of certain sleep disorders are also reviewed.

The two faces of Eve Dopamine’s modulation of wakefulness and sleep

Abstract: In Parkinson's disease (PD), waking is frequently punctuated by sleep episodes, including rapid eye movement (REM) (i.e., dream) sleep, and sleep is interrupted by motor activities such as periodic limb movements and REM sleep behavior disorder. Because these pathologic behaviors are unaccounted for by contemporary models, this review summarizes the complex effects of dopamine (DA) on normal and pathological waking-sleeping. Maintenance of wakefulness is probably promoted by mesocorticolimbic DA circuits, and suppression of nocturnal movement appears to be influenced by indirect pathways linking midbrain DA neurons with pre-motor structures in the mesopontine tegmentum and ventromedial medulla. A diencephalospinal DA system may have an additional important role in mediating state-specific sensorimotor activity that is relevant to periodic limb movements and restless legs syndrome.

Increased production of evoked and spontaneous K-complexes following a night of fragmented sleep.

Abstract: Study objectives To determine whether K-complex production is better interpreted as being an arousal response or reflective of a sleep protective micro-state. Design A 3-night study--night 1 as a baseline night, night 2 as a sleep fragmentation night, followed immediately by night 3 as a recovery night. On nights 1 and 3, approximately 400 auditory stimuli were presented during nonREM sleep in the first two sleep cycles, using stimulus parameters previously found to be optimal for K-complex production. Setting The sleep research laboratory at the University of Melbourne. Participants Six young healthy subjects (3 female). Interventions One night of sleep fragmentation. Ten-second auditory tones of up to 110 dB were presented throughout the entire night at approximately 1-minute intervals. Measurements and results Sleep drive was increased on the recovery night, as indicated by increased amounts of slow wave sleep, increased sleep efficiency, and a reduction in stimulus-related alpha activity. The incidence of both evoked and spontaneous K-complexes increased significantly on the recovery night. When K-complex trials were averaged, neither N550 (Fz) amplitude nor latency differed between the 2 nights. When vertex sharp waves were averaged, N350 (Cz) amplitude was increased significantly on the recovery night. Conclusions The increase in K-complex frequency together with the decrease seen in stimulus-related alpha activity supports the view that they reflect a sleep maintenance, rather than an arousal, response.