title: Gray matter-specific changes in brain bioenergetics after acute sleep deprivation: a 31P magnetic resonance spectroscopy study at 4 Tesla.
abstract: OBJECTIVE
  A principal function of sleep may be restoration of brain energy metabolism caused by the energetic demands of wakefulness. Because energetic demands in the brain are greater in gray than white matter, this study used linear mixed-effects models to examine tissue-type specific changes in high-energy phosphates derived using 31P magnetic resonance spectroscopy (MRS) after sleep deprivation and recovery sleep.
  
  
  METHODS
  Experimental laboratory study.
  
  
  METHODS
  Outpatient neuroimaging center at a private psychiatric hospital.
  
  
  METHODS
  A total of 32 MRS scans performed in eight healthy individuals (mean age 35 y; range 23-51 y).
  
  
  METHODS
  Phosphocreatine (PCr) and β-nucleoside triphosphate (NTP) were measured using 31P MRS three dimensional-chemical shift imaging at high field (4 Tesla) after a baseline night of sleep, acute sleep deprivation (SD), and 2 nights of recovery sleep. Novel linear mixed-effects models were constructed using spectral and tissue segmentation data to examine changes in bioenergetics in gray and white matter.
  
  
  RESULTS
  PCr increased in gray matter after 2 nights of recovery sleep relative to SD with no significant changes in white matter. Exploratory analyses also demonstrated that increases in PCr were associated with increases in electroencephalographic slow wave activity during recovery sleep. No significant changes in β-NTP were observed.
  
  
  CONCLUSIONS
  These results demonstrate that sleep deprivation and subsequent recovery-induced changes in high-energy phosphates primarily occur in gray matter, and increases in PCr after recovery sleep may be related to sleep homeostasis.
authors.affiliation: Department of Psychiatry, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: David T
authors.initials: DT
authors.lastname: Plante
authors.affiliation: Behavioral Psychopharmacology Research Lab, McLean Hospital, Belmont, MA: Brain Imaging Center, McLean Hospital, Belmont, MA: Sleep Research Laboratory, McLean Hospital, Belmont, MA: Harvard Medical School, Boston, MA.
authors.forename: George H
authors.initials: GH
authors.lastname: Trksak
authors.affiliation: Brain Imaging Center, McLean Hospital, Belmont, MA: Harvard Medical School, Boston, MA.
authors.forename: J Eric
authors.initials: JE
authors.lastname: Jensen
authors.affiliation: Behavioral Psychopharmacology Research Lab, McLean Hospital, Belmont, MA: Brain Imaging Center, McLean Hospital, Belmont, MA: Sleep Research Laboratory, McLean Hospital, Belmont, MA: Harvard Medical School, Boston, MA.
authors.forename: David M
authors.initials: DM
authors.lastname: Penetar
authors.affiliation: Harvard Medical School, Boston, MA: Laboratory for Psychiatric Biostatistics, McLean Hospital, Belmont, MA.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Ravichandran
authors.affiliation: Department of Psychiatry, University of Wisconsin School of Medicine and Public Health, Madison, WI.
authors.forename: Brady A
authors.initials: BA
authors.lastname: Riedner
authors.affiliation: Sleep Research Laboratory, McLean Hospital, Belmont, MA.
authors.forename: Wendy L
authors.initials: WL
authors.lastname: Tartarini
authors.affiliation: Brain Imaging Center, McLean Hospital, Belmont, MA: Sleep Research Laboratory, McLean Hospital, Belmont, MA: Harvard Medical School, Boston, MA.
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Dorsey
authors.affiliation: The Brain Institute, University of Utah School of Medicine, Salt Lake City, UT.
authors.forename: Perry F
authors.initials: PF
authors.lastname: Renshaw
authors.affiliation: Behavioral Psychopharmacology Research Lab, McLean Hospital, Belmont, MA: Brain Imaging Center, McLean Hospital, Belmont, MA: Sleep Research Laboratory, McLean Hospital, Belmont, MA: Harvard Medical School, Boston, MA.
authors.forename: Scott E
authors.initials: SE
authors.lastname: Lukas
authors.affiliation: Harvard Medical School, Boston, MA: Geriatric Psychiatry Program, McLean Hospital, Belmont, MA.
authors.forename: David G
authors.initials: DG
authors.lastname: Harper
mesh_terms: D000328:Adult; D004569:Electroencephalography; D004734:Energy Metabolism; D005260:Female; D066128:Gray Matter / Q000378:metabolism* / Q000503:physiopathology; D064368:Healthy Volunteers; D006706:Homeostasis; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009711:Nucleotides / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D064210:Secondary Metabolism; D012890:Sleep / Q000502:physiology; D012892:Sleep Deprivation / Q000378:metabolism* / Q000503:physiopathology; D066127:White Matter / Q000378:metabolism; D055815:Young Adult
chemical_list: D009711:Nucleotides; D010725:Phosphocreatine
keywords: magnetic resonance spectroscopy; nucleoside triphosphate; phosphocreatine; sleep deprivation