title: Adolescent changes in homeostatic regulation of EEG activity in the delta and theta frequency bands during NREM sleep.
abstract: OBJECTIVE
  Slow wave EEG activity in NREM sleep decreases by more than 60% between ages 10 and 20 years. Slow wave EEG activity also declines across NREM periods (NREMPs) within a night, and this decline is thought to represent the dynamics of sleep homeostasis. We used longitudinal data to determine whether these homeostatic dynamics change across adolescence.
  
  
  METHODS
  All-night sleep EEG was recorded semiannually for 6 years.
  
  
  METHODS
  EEG was recorded with ambulatory recorders in the subjects' homes.
  
  
  METHODS
  Sixty-seven subjects in 2 cohorts, one starting at age 9 and one starting at age 12 years.
  
  
  RESULTS
  For NREM delta (1-4 Hz) and theta (4-8 Hz) EEG, we tested whether the proportion of spectral energy contained in the first NREMP changes with age. We also tested for age changes in the parameters of the process S exponential decline. For both delta and theta, the proportion of energy in the first NREMP declined significantly across ages 9 to 18 years. Process S parameters SWA(0) and TWA(0), respectively, represent slow wave (delta) activity and theta wave activity at the beginning of the night. SWA(0) and TWA(0) declined significantly (P < 0.0001) across ages 9 to 18.
  
  
  CONCLUSIONS
  These declines indicate that the intensity of the homeostatic or restorative processes at the beginning of sleep diminished across adolescence. We propose that this change in sleep regulation is caused by the synaptic pruning that occurs during adolescent brain maturation.
authors.affiliation: University of California Davis, Department of Psychiatry and Behavioral Sciences, Davis, CA 95618, USA. igcampbell@ucdavis.edu
authors.forename: Ian G
authors.initials: IG
authors.lastname: Campbell
authors.forename: Nato
authors.initials: N
authors.lastname: Darchia
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Higgins
authors.forename: Igor V
authors.initials: IV
authors.lastname: Dykan
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Davis
authors.forename: Evan
authors.initials: E
authors.lastname: de Bie
authors.forename: Irwin
authors.initials: I
authors.lastname: Feinberg
mesh_terms: D000293:Adolescent; D000375:Aging / Q000502:physiology; D000513:Alpha Rhythm / Q000502:physiology*; D002648:Child; D005260:Female; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D008297:Male; D012894:Sleep Stages / Q000502:physiology*; D013826:Theta Rhythm / Q000502:physiology*