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.

Sleep Stage Characteristics of Long and Short Sleepers

Abstract: The possibility of different sleep stage characteristics being associated with different sleep lengths was explored by comparing two groups of high school seniors, who characteristically slept 6(1/2) hours or less or who slept 8(1/2) hours or more, with an age-matched control group not selected on the basis of sleep length. All-night electroencephalography was used to examine the sleep stage characteristics of these groups. Compared with the unselected age-matched group, the short sleepers showed no significant diminution in their stage 4 (deep) or rapid eye movement (dream) sleep. The long sleepers were observed to obtain significantly more rapid eye movement sleep than did the other groups.

Experience-dependent slow-wave sleep development

Abstract: Sleep enhances plasticity in neocortex, and thereby improves sensory learning1. Here we show that sleep itself undergoes changes as a consequence of waking experience during a late critical period in cats and mice. Dark-rearing produced a robust and reversible decrement of slow-wave electrical activity during sleep that was restricted to visual cortex and impaired by gene-targeted reduction of NMDA receptor function.

Arousal thresholds during human tonic and phasic REM sleep.

Abstract: The goal of the present study was to investigate arousal thresholds (ATs) in tonic and phasic episodes of rapid eye movement (REM) sleep, and to compare the frequency spectrum of these sub-states of REM to non-REM (NREM) stages of sleep. We found the two REM stages to differ with regard to behavioural responses to external acoustic stimuli. The AT in tonic REM was indifferent from that in sleep stage 2, and ATs in phasic REM were similar to those in slow-wave sleep (stage 4). NREM and REM stages of similar behavioural thresholds were distinctly different with regard to their frequency pattern. These data provide further evidence that REM sleep should not be regarded a uniform state. Regarding electroencephalogram frequency spectra, we found that the two REM stages were more similar to each other than to NREM stages with similar responsivity. Ocular activity such as ponto-geniculo-occipital-like waves and microsaccades are discussed as likely modulators of behavioural responsiveness and cortical processing of auditory information in the two REM sub-states.

Diversity of receptive field changes in auditory cortex during natural sleep.

Abstract: Twenty years ago, the study by Livingstone and Hubel [(1981) Nature, 291, 554] was viewed as a first step toward understanding how changes in state of vigilance affect sensory processing. Since then, however, very few attempts have been made to progress in this direction. In the present study, 56 cells were recorded in the auditory cortex of adult, undrugged guinea pigs, and the frequency tuning curves were tested during continuous and stable periods of wakefulness and of slow-wave sleep (SWS). Twelve cells were also tested during paradoxical sleep. Over the whole cell population, the response latency, the frequency selectivity and the size of the suprathreshold receptive field were not significantly modified during SWS compared with waking. However, this lack of global effects resulted from the heterogeneity of response changes displayed by cortical cells. During SWS, the receptive field size varied as a function of the changes in evoked responses: it was unchanged for the cells whose evoked responses were not modified (38% of the cells), reduced for the cells whose responses were decreased (48%) and enlarged for the cells whose responses were increased (14%). This profile of changes differs from the prevalent receptive field shrinkage that was observed in the auditory thalamus during SWS [Edeline et al. (2000), J. Neurophysiol., 84, 934]. It also contrasts with the receptive field enlargement that was described under anaesthesia when the EEG spontaneously shifted from a desynchronized to a synchronized pattern [Worgotter et al. (1998), Nature, 396, 165]. Reasons for these differences are discussed.

Natural and melatonin-induced sleep in young chickens--a behavioral and electrographic study.

Abstract: 1. Natural sleep and waking states of young chickens were studied by polygraphic recording (EEG, EOG, EMG and ECG) together with behavioral observation. Effects of melatonin were observed. 2. The sleep-wake periods of the chickens were analysed for three states: awake, slow wave sleep (SS) and paradoxical sleep (PS). Polygraphic characteristics of these 3 states were analogous to, though in several aspects different from, those in mammalians. 3. The sleep states alternated irregularly at short intervals. SS usually did not last longer than 6 min without being interrupted by an episode of arousal or PS. PS appeared at irregular intervals usually lasting only 6–8 sec. Total duration of PS was 7.3±1.8% of total sleep time. 4. Melatonin (0.01–0.06 mg/g) had a powerful sedative and hypnotic effect which appeared within 1–2 min after i. perit. injection and lasted for 30–60 min. Melatonin-induced sleep was characterized by slow EEG activity of high voltage similar to that in normal SS but with a higher incidence of 2–3 c/sec waves. 5. Melatonin besides activating SS, delayed the appearence of the first PS episode and decreased total PS time. 6. In melatonin sleep as in natural sleep the chickens were easily aroused by sensory stimuli both in behavior and electrographic pattern. 7. Possible mechanisms related to sleep-inducing effects of melatonin are discussed.