title: The maturation of cortical sleep rhythms and networks over early development.
abstract: OBJECTIVE
  Although neuronal activity drives all aspects of cortical development, how human brain rhythms spontaneously mature remains an active area of research. We sought to systematically evaluate the emergence of human brain rhythms and functional cortical networks over early development.
  
  
  METHODS
  We examined cortical rhythms and coupling patterns from birth through adolescence in a large cohort of healthy children (n=384) using scalp electroencephalogram (EEG) in the sleep state.
  
  
  RESULTS
  We found that the emergence of brain rhythms follows a stereotyped sequence over early development. In general, higher frequencies increase in prominence with striking regional specificity throughout development. The coordination of these rhythmic activities across brain regions follows a general pattern of maturation in which broadly distributed networks of low-frequency oscillations increase in density while networks of high frequency oscillations become sparser and more highly clustered.
  
  
  CONCLUSIONS
  Our results indicate that a predictable program directs the development of key rhythmic components and physiological brain networks over early development.
  
  
  CONCLUSIONS
  This work expands our knowledge of normal cortical development. The stereotyped neurophysiological processes observed at the level of rhythms and networks may provide a scaffolding to support critical periods of cognitive growth. Furthermore, these conserved patterns could provide a sensitive biomarker for cortical health across development.
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Boston, MA 02144, USA; Harvard Medical School, Boston, MA 02144, USA. Electronic address: cjchu@hms.harvard.edu.
authors.forename: C J
authors.initials: CJ
authors.lastname: Chu
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Boston, MA 02144, USA.
authors.forename: J
authors.initials: J
authors.lastname: Leahy
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Boston, MA 02144, USA; Harvard Medical School, Boston, MA 02144, USA.
authors.forename: J
authors.initials: J
authors.lastname: Pathmanathan
authors.affiliation: Department of Mathematics and Statistics, Boston University, Boston, MA 02215, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Kramer
authors.affiliation: Department of Neurology, Massachusetts General Hospital, Boston, MA 02144, USA; Harvard Medical School, Boston, MA 02144, USA.
authors.forename: S S
authors.initials: SS
authors.lastname: Cash
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001931:Brain Mapping / Q000379:methods; D002540:Cerebral Cortex / Q000254:growth & development*; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm / Q000502:physiology; D004569:Electroencephalography; D004585:Electrooculography; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009415:Nerve Net / Q000254:growth & development*; D016571:Neural Networks, Computer; D012016:Reference Values; D012890:Sleep / Q000502:physiology*
keywords: Brain networks; Brain rhythms; Development; EEG; Functional connectivity; Sleep