Regional difference in GABA levels between medial prefrontal and occipital cortices.
OBJECTIVE
To avoid the confounding effects of variations in tissue composition this study measured regional GABA differences using two voxels with the same tissue composition.


METHODS
Eighteen healthy adult volunteers were scanned using a 3 Tesla GE clinical scanner with a J-coupling based editing sequence. Spectroscopy voxels were placed in the medial prefrontal (MPFC) and occipital cortex (OCC) with essentially the same gray and white matter fractions.


RESULTS
A 16% (P = 0.0001) significantly higher GABA to creatine ratio was found in the OCC (0.1103 ± 0.0050) compared with the MPFC (0.0953 ± 0.0041). When normalized to tissue water, GABA concentrations in the OCC were 14% higher than in the MPFC.


CONCLUSIONS
A difference in GABA concentration was found between the OCC and MPFC voxels in healthy subjects which is attributable to differences other than tissue composition.
Magnetic Resonance Spectroscopy Core Facility, National Institute of Mental Health, National Institutes of Health, MD 20892, USA. veen@nih.gov
Jan Willem
JW
van der Veen
Jun
J
Shen
D000328:Adult; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000033:anatomy & histology / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000033:anatomy & histology / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D005680:gamma-Aminobutyric Acid
N-acetylaspartate (NAA); creatine; gamma-aminobutyric acid (GABA); glutamate &plus; glutamine (Glx); gray matter; occipital cortex; prefrontal cortex; white matter