Dataset Information

Cortical development, electroencephalogram rhythms, and the sleep/wake cycle.

ABSTRACT: During adulthood, electroencephalogram (EEG) recordings are used to distinguish wake, non-rapid eye movement sleep, and rapid eye movement sleep states. The close association between behavioral states and EEG rhythms is reached late during development, after birth in humans and by the end of the second postnatal week in rats and mice. This critical time is also when cortical activity switches from a discontinuous to a continuous pattern. We review the major cellular and network changes that can account for this transition. After this close link is established, new evidence suggests that the slow waves of non-rapid eye movement sleep may function as markers to track cortical development. However, before the EEG can be used to identify behavioral states, two distinct sleep phases--quiet sleep and active sleep--are identified based on behavioral criteria and muscle activity. During this early phase of development, cortical activity is far from being disorganized, despite the presence of long periods of neuronal silence and the poor modulation by behavioral states. Specific EEG patterns, such as spindle bursts and gamma oscillations, have been identified very early on and are believed to play a significant role in the refinement of brain circuits. Because most early EEG patterns do not map to a specific behavioral state, their contribution to the presumptive role of sleep in brain maturation remains to be established and should be a major focus for future research.

SUBMITTER: Cirelli C

PROVIDER: S-EPMC4444390 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

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Cortical development, electroencephalogram rhythms, and the sleep/wake cycle.

Cirelli Chiara C Tononi Giulio G

Biological psychiatry 20141224 12

During adulthood, electroencephalogram (EEG) recordings are used to distinguish wake, non-rapid eye movement sleep, and rapid eye movement sleep states. The close association between behavioral states and EEG rhythms is reached late during development, after birth in humans and by the end of the second postnatal week in rats and mice. This critical time is also when cortical activity switches from a discontinuous to a continuous pattern. We review the major cellular and network changes that can ...[more]

PMID: 25680672

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Project description:BackgroundScale-invariant neuronal avalanches have been observed in cell cultures and slices as well as anesthetized and awake brains, suggesting that the brain operates near criticality, i.e. within a narrow margin between avalanche propagation and extinction. In theory, criticality provides many desirable features for the behaving brain, optimizing computational capabilities, information transmission, sensitivity to sensory stimuli and size of memory repertoires. However, a thorough characterization of neuronal avalanches in freely-behaving (FB) animals is still missing, thus raising doubts about their relevance for brain function.Methodology/principal findingsTo address this issue, we employed chronically implanted multielectrode arrays (MEA) to record avalanches of action potentials (spikes) from the cerebral cortex and hippocampus of 14 rats, as they spontaneously traversed the wake-sleep cycle, explored novel objects or were subjected to anesthesia (AN). We then modeled spike avalanches to evaluate the impact of sparse MEA sampling on their statistics. We found that the size distribution of spike avalanches are well fit by lognormal distributions in FB animals, and by truncated power laws in the AN group. FB data surrogation markedly decreases the tail of the distribution, i.e. spike shuffling destroys the largest avalanches. The FB data are also characterized by multiple key features compatible with criticality in the temporal domain, such as 1/f spectra and long-term correlations as measured by detrended fluctuation analysis. These signatures are very stable across waking, slow-wave sleep and rapid-eye-movement sleep, but collapse during anesthesia. Likewise, waiting time distributions obey a single scaling function during all natural behavioral states, but not during anesthesia. Results are equivalent for neuronal ensembles recorded from visual and tactile areas of the cerebral cortex, as well as the hippocampus.Conclusions/significanceAltogether, the data provide a comprehensive link between behavior and brain criticality, revealing a unique scale-invariant regime of spike avalanches across all major behaviors.

Dataset Information

Cortical development, electroencephalogram rhythms, and the sleep/wake cycle.

Publications

Cortical development, electroencephalogram rhythms, and the sleep/wake cycle.

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