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During much of sleep, virtually all cortical neurons undergo a slow oscillation (<1 Hz) in membrane potential, cycling from a hyperpolarized state of silence to a depolarized state of intense firing. This slow oscillation is the fundamental cellular phenomenon that organizes other sleep rhythms such as spindles and slow waves. Using high-density(More)
When we fall asleep, consciousness fades yet the brain remains active. Why is this so? To investigate whether changes in cortical information transmission play a role, we used transcranial magnetic stimulation together with high-density electroencephalography and asked how the activation of one cortical area (the premotor area) is transmitted to the rest of(More)
STUDY OBJECTIVES The mechanisms responsible for the homeostatic decrease of slow-wave activity (SWA, defined in this study as electroencephalogram [EEG] power between 0.5 and 4.0 Hz) during sleep are unknown. In agreement with a recent hypothesis, in the first of 3 companion papers, large-scale computer simulations of the sleeping thalamocortical system(More)
Aquifex aeolicus was one of the earliest diverging, and is one of the most thermophilic, bacteria known. It can grow on hydrogen, oxygen, carbon dioxide, and mineral salts. The complex metabolic machinery needed for A. aeolicus to function as a chemolithoautotroph (an organism which uses an inorganic carbon source for biosynthesis and an inorganic chemical(More)
Sleep slow wave activity (SWA) is thought to reflect sleep need, increasing after wakefulness and decreasing after sleep. We showed recently that a learning task involving a circumscribed brain region produces a local increase in sleep SWA. We hypothesized that increases in cortical SWA reflect synaptic potentiation triggered by learning. To further(More)
Slow waves are the most prominent electroencephalographic (EEG) feature of sleep. These waves arise from the synchronization of slow oscillations in the membrane potentials of millions of neurons. Scalp-level studies have indicated that slow waves are not instantaneous events, but rather they travel across the brain. Previous studies of EEG slow waves were(More)
Repetitive transcranial magnetic stimulation (rTMS) is increasingly being used to promote cortical reorganization, under the assumption that it can induce long-term potentiation (LTP) of neural responses. This assumption is supported by several lines of indirect evidence. For example, rTMS of motor cortex can induce a potentiation of muscle motor evoked(More)
Most of us sleep 7-8 h per night, and if we are deprived of sleep our performance suffers greatly; however, a few do well with just 3-4 h of sleep-a trait that seems to run in families. Determining which genes underlie this phenotype could shed light on the mechanisms and functions of sleep. To do so, we performed mutagenesis in Drosophila melanogaster,(More)
Gene targeted mice can be used as models to investigate the mechanisms underlying sleep regulation. Three commonly used background strains for gene targeting (129/Ola, 129/SvJ and C57BL/6J) were subjected to 4-h and 6-h sleep deprivation (SD), and their sleep and sleep EEG were continuously recorded. The two-process model of sleep regulation has predicted(More)