title: Edited magnetic resonance spectroscopy detects an age-related decline in brain GABA levels.
abstract: Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the brain. Although measurements of GABA levels in vivo in the human brain using edited proton magnetic resonance spectroscopy ((1)H-MRS) have been established for some time, it is has not been established how regional GABA levels vary with age in the normal human brain. In this study, 49 healthy men and 51 healthy women aged between 20 and 76 years were recruited and J-difference edited spectra were recorded at 3T to determine the effect of age on GABA levels, and to investigate whether there are regional and gender differences in GABA in mesial frontal and parietal regions. Because the signal detected at 3.02 ppm using these experimental parameters is also expected to contain contributions from both macromolecules (MM) and homocarnosine, in this study the signal is labeled GABA+ rather than GABA. Significant negative correlations were observed between age and GABA+ in both regions studied (GABA+/Cr: frontal region, r=-0.68, p<0.001, parietal region, r=-0.54, p<0.001; GABA+/NAA: frontal region, r=-0.58, p<0.001, parietal region, r=-0.49, p<0.001). The decrease in GABA+ with age in the frontal region was more rapid in women than men. Evidence of a measureable decline in GABA is important in considering the neurochemical basis of the cognitive decline that is associated with normal aging.
authors.affiliation: Shandong Medical Imaging Research Institute, Shandong University, Jinan, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.forename: Richard A E
authors.initials: RA
authors.lastname: Edden
authors.forename: Muwei
authors.initials: M
authors.lastname: Li
authors.forename: Nicolaas A J
authors.initials: NA
authors.lastname: Puts
authors.forename: Guangbin
authors.initials: G
authors.lastname: Wang
authors.forename: Cheng
authors.initials: C
authors.lastname: Liu
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
authors.forename: Huiquan
authors.initials: H
authors.lastname: Wang
authors.forename: Xue
authors.initials: X
authors.lastname: Bai
authors.forename: Chen
authors.initials: C
authors.lastname: Zhao
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.forename: Peter B
authors.initials: PB
authors.lastname: Barker
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012727:Sex Characteristics; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
chemical_list: D005680:gamma-Aminobutyric Acid