M ajor depressive disorders (MDD) are associated with a variety of sleep macroarchitectural disturbances, based on visual stage scoring of the sleep electroencephalogram (EEG). These include insomnia, impaired sleep continuity, abnormalities in the amount and timing of rapid eye movement (REM) sleep, reductions in deep non-REM (NREM) sleep, increased awakenings during the night and increased li...

Sleep has beneficial effects on brain function and learning, which are reflected in plastic changes in the cortex. Early childhood is a time of rapid maturation in fundamental skills-e.g., language, cognitive control, working memory-that are predictive of future functioning. Little is currently known about the interactions between sleep and brain maturation during this developmental period. We ...

This study presents data on some phasic EEG phenomena regulary recorded during sleep - wakefulness cycle and heterogeneity of EEG sleep stages forming consecutive human sleep macrocycles. These short-term EEG changes quite often tend to periodization, especially during initial sleep-stages and transitive states (sleep microcycles). An attempt was made to reveal EEG microstructures in sleep - wa...

The sleep EEGs of 9 young adult males (age 20-28 years) and 8 middle-aged males (42-56 years) were analyzed by visual scoring and spectral analysis. In the middle-aged subjects power density in the delta, theta and sigma frequencies were attenuated as compared to the young subjects. In both age groups power density in the delta and theta frequencies declined from NREM period 1 to 3. In the sigm...

Discrepancy between objective and subjective sleep, referred to as sleep misperception, is common in normal sleepers but is most evident in insomniacs (1). Sleep and wake stages are typically defined by electroencephalographic (EEG) patterns. EEG is only one neurophysiological aspect of the sleep state and researchers have tried to correlate other factors with EEG sleep/wake patterns. These fac...

OBJECTIVE Self-reported sleep disturbances are present in over 80% of patients with depression. However, sleep electroencephalography (EEG) findings, based on overnight polysomnography have not always differentiated depressed patients from healthy individuals. METHOD The present paper will review the findings on sleep EEG studies in depression highlighting how recent technological and methodo...

STUDY OBJECTIVES Hemispheric stroke in humans is associated with sleep-wake disturbances and sleep electroencephalogram (EEG) changes. The correlation between these changes and stroke extent remains unclear. In the absence of experimental data, we assessed sleep EEG changes after focal cerebral ischemia of different extensions in mice. DESIGN Following electrode implantation and baseline slee...

Research in recent years has supported the hypothesis that many properties of the electroencephalogram (EEG) are specific to an individual. In this study, the intra- and inter-individual variations of sleep EEG signals were investigated. This was carried out by analyzing the stability of the average EEG spectra individually computed for the Rechtschaffen and Kales (RK) sleep stages. Six EEG cha...

Slow wave oscillations in the electroencephalogram (EEG) during sleep may reflect both sleep need and intensity, which are implied in homeostatic regulation. Adenosine is strongly implicated in sleep homeostasis, and a single nucleotide polymorphism in the adenosine deaminase gene (ADA G22A) has been associated with deeper and more efficient sleep. The present study verified the association bet...