title: Glutamate, GABA, and other cortical metabolite concentrations during early abstinence from alcohol and their associations with neurocognitive changes.
abstract: BACKGROUND
  Little is known about the effects of alcohol dependence on cortical concentrations of glutamate (Glu) or gamma aminobutyric acid (GABA). We used proton magnetic resonance spectroscopy (MRS) to study cross-sectionally and longitudinally the concentrations of these in alcohol dependent individuals (ALC) during early abstinence from alcohol.
  
  
  METHODS
  Twenty ALC were studied at about one week of abstinence from alcohol (baseline) and 36 ALC at five weeks of abstinence and compared to 16 light/non-drinking controls (LD). Eleven ALC were studied twice during abstinence. Participants underwent clinical interviewing, blood work, neuropsychological testing, structural imaging and single-volume proton MRS at 4Tesla. Absolute concentrations of Glu, GABA and those of other (1)H MRS-detectable metabolites were measured in the anterior cingulate (ACC), parieto-occipital cortex (POC) and dorso-lateral prefrontal cortex (DLPFC). Relationships of metabolite levels to drinking severity and neurocognition were also assessed.
  
  
  RESULTS
  ALC at baseline had lower concentrations of Glu, N-acetylaspartate (NAA), choline- (Cho) and creatine-containing metabolites (Cr) than LD in the ACC, but had normal GABA and myo-inositol (mI) levels. At five weeks of abstinence, metabolite concentrations were not significantly different between groups. Between one and five weeks of abstinence, Glu, NAA and Cho levels in the ACC increased significantly. Higher cortical mI concentrations in ALC related to worse neurocognitive outcome.
  
  
  CONCLUSIONS
  These MRS data suggest compromised and regionally specific bioenergetics/metabolism in one-week-abstinent ALC that largely normalizes over four weeks of sustained abstinence. The correlation between mI levels and neurocognition affirms the functional relevance of this putative astrocyte marker.
authors.affiliation: Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA. Anderson.Mon@ucsf.edu
authors.forename: Anderson
authors.initials: A
authors.lastname: Mon
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Durazzo
authors.forename: Dieter J
authors.initials: DJ
authors.lastname: Meyerhoff
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000378:metabolism* / Q000523:psychology* / Q000534:rehabilitation; D000465:Algorithms; D001923:Brain Chemistry; D002540:Cerebral Cortex / Q000378:metabolism*; D003071:Cognition / Q000502:physiology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007858:Learning / Q000502:physiology; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008568:Memory / Q000502:physiology; D008570:Memory, Short-Term / Q000502:physiology; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology; D012959:Socioeconomic Factors; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid