title: Anterior cingulate and cerebellar GABA and Glu correlations measured by ¹H J-difference spectroscopy.
abstract: Gamma-aminobutyric acid (GABA) and glutamate (Glu) levels, normalized to total creatine (tCr), were measured in the anterior cingulate and cerebellar vermis in healthy adults (n=19, age=24.6±6.4 years) using ¹H MRS at 3 T, and metabolite correlations across regions and subjects were determined. Mean anterior cingulate and cerebellar GABA/tCr ratios were 0.31 (0.08) and 0.23 (0.06), respectively, while corresponding Glu levels were 1.16 (0.10) and 0.70 (0.07), respectively. Anterior cingulate and cerebellar glutamate levels were correlated (r=0.6103, P=.0140), although it is noted that when adjusted for multiple comparisons, all correlations reported here cluster to a P value of .0583. It is unlikely that this correlation is driven by correlations in tCr, since interregional correlations were not observed for other metabolites referenced to tCr. Correlations were also observed among metabolites in both the anterior cingulate and cerebellar vermis. In the former, N-acetylasparate was linearly dependent on glutamate (r=0.6577, P=.0063) and, at or below this significance threshold, four metabolites were correlated in the cerebellar vermis (Ins/tCh: r=0.6261, P=.0109. NAA/tCh: r=0.6426, P=.0082. NAA/Glu: r=0.6412, P=.0085. tCh/Glu: r=0.6193, P=0.0122).
authors.affiliation: Institute of Imaging Science, Vanderbilt University, Nashville, TN 37232-2310, USA. kevin.waddell@vanderbilt.edu
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Waddell
authors.forename: Parham
authors.initials: P
authors.lastname: Zanjanipour
authors.forename: Subechhya
authors.initials: S
authors.lastname: Pradhan
authors.forename: Lei
authors.initials: L
authors.lastname: Xu
authors.forename: Edward B
authors.initials: EB
authors.lastname: Welch
authors.forename: James M
authors.initials: JM
authors.lastname: Joers
authors.forename: Peter R
authors.initials: PR
authors.lastname: Martin
authors.forename: Malcolm J
authors.initials: MJ
authors.lastname: Avison
authors.forename: John C
authors.initials: JC
authors.lastname: Gore
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D002531:Cerebellum / Q000378:metabolism*; D003401:Creatine / Q000378:metabolism*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006179:Gyrus Cinguli / Q000378:metabolism*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D011522:Protons; D013223:Statistics as Topic; D014018:Tissue Distribution; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D011522:Protons; D001224:Aspartic Acid; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; C000179:N-acetylaspartate; D003401:Creatine