Aging of the adult human brain: In vivo quantitation of metabolite content with proton magnetic resonance spectroscopy

Proton NMR chemical shifts and coupling constants for brain metabolites

“…Decreased NAA concentrations in cortical gray matter have been reported with age, 53 although no correlations were observed in another report. 54 …”

Baseline GABA concentration and fMRI response

“…The conclusion of that study was that GABA normalized by creatine tended to show the best reproducibility. Additionally, the use of creatine as an internal reference is fairly common practice because its concentration has been shown to be fairly stable across individuals, regardless of age (Saunders et al, 1999). In this study, where all of the subjects are healthy individuals, we believe this to be a reasonable approach.…”

Long-term calorie restriction has minimal impact on brain metabolite and fatty acid profiles in aged rats on a Western-style diet

“…NMR spectroscopy results were classically expressed as a ratio to creatine, since the latter is thought to remain steady across brain regions and individuals (Pouwels and Frahm, 1998;Saunders et al, 1999). However, significantly higher brain creatine concentration has been reported in aged rats (Paban et al, 2010) and in the healthy elderly (Chang et al, 1996;Haga et al, 2009;Schuff et al, 2001).…”

“…In the brain, these constituents include those associated with energy metabolism (glucose, lactate and amino acids) and neurotransmission (glutamine, glutamate, c-aminobutyric acid). NMR spectroscopy has been previously used to study changes in brain metabolites during aging in rodents (Katz-Brull et al, 2002), humans (Boumezbeur et al, 2010;Haga et al, 2009;Saunders et al, 1999) and age-related diseases affecting the brain including Alzheimer's disease (Dedeoglu et al, 2004;Esteras et al, 2012;Huang et al, 2001;Kantarci et al, 2000). High resolution magic angle spinning (HRMAS)-NMR spectroscopy provides highly resolved spectra of metabolite profiles on samples of intact tissue without preparative extraction procedures (Ratai et al, 2005).…”