title: Effects of age and sex on the concentrations of glutamate and glutamine in the human brain.
abstract: OBJECTIVE
  To determine the effects of age and sex on cerebral glutamate and glutamine concentrations in a large sample of healthy humans using a dedicated measuring and evaluation procedure. Exploratory examinations of other brain metabolites were also conducted.
  
  
  METHODS
  In 118 healthy subjects aged 19 to 55 years (59 female) absolute concentrations of glutamate, glutamine, N-acetylaspartate (NAA), total creatine, and total choline (tCho) in voxels comprising the left hippocampus (HC) and the anterior cingulate cortex (ACC) were investigated using point-resolved spectroscopy with an echo time of 80 ms at 3 Tesla in combination with a reliable quantification procedure. Special care was taken to correct for multiple comparisons.
  
  
  RESULTS
  An age-related decline of the concentrations of glutamate in both regions studied was observed whereas glutamine levels in ACC increased with age. Statistically significant sex-related differences were detected for glutamate in the HC and for tCho in the ACC. NAA decreased with age in both regions, the significance not surviving Bonferroni correction.
  
  
  CONCLUSIONS
  The results demonstrate effects of age and gender on glutamate, glutamine, choline containing compounds, and NAA in healthy human brain. They add to the growing evidence for gender-specific differences in cerebral neurotransmission, metabolism, and structure across the lifespan.
authors.affiliation: Department of Psychiatry and Psychotherapy, Psychiatric University Hospital St. Hedwig, Charité - University Medicine Berlin, Campus Mitte, Berlin, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Hädel
authors.forename: Christoph
authors.initials: C
authors.lastname: Wirth
authors.forename: Michael
authors.initials: M
authors.lastname: Rapp
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
authors.forename: Florian
authors.initials: F
authors.lastname: Schubert
mesh_terms: D000328:Adult; D000375:Aging / Q000378:metabolism*; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D002794:Choline / Q000378:metabolism*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006179:Gyrus Cinguli / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012737:Sex Factors; D055815:Young Adult
chemical_list: D018377:Neurotransmitter Agents; D005973:Glutamine; D001224:Aspartic Acid; D018698:Glutamic Acid; C000179:N-acetylaspartate; D002794:Choline
keywords: age; brain metabolites; glutamate; glutamine; magnetic resonance spectroscopy; sex