Reliability of glutamate and GABA quantification using proton magnetic resonance spectroscopy

The consistency and reliability of proton magnetic resonance spectroscopy (H-1-MRS) assessments of neurotransmitter concentration has not been widely examined over multiple days. The purpose of this study was to determine the reliability of glutamate and GABA measures using a single-voxel H-1-MRS protocol in healthy men and women. Glutamate and GABA quantitations were obtained from the primary motor cortex (M1) and the dorsolateral prefrontal cortex (DLPFC) in 13 healthy individuals across 3 data collection sessions, including a baseline (Visit 1), 2-week (Visit 2), and 2-month time point (Visit 3). Glutamate concentrations were similar across visits in Ml (p = 0.72) and the DLPFC (p = 0.52). Reliability across days was excellent in Ml (R= 0.93), and in the DLPFC (R= 0.99). GABA concentrations were similar across visits in Ml (p = 0.44) and in the DLPFC (p = 0.59). Reliability of GABA concentration across days was excellent in Ml (R= 0.93), and in the DLPFC (R= 0.97). H-1-MRS is a reliable method for quantifying glutamate and GABA concentration in Ml and the DLPFC in humans. (C) 2017 Elsevier B.V. All rights reserved.