Age-related Differences In Metabolites In The Anterior And Posterior Cingulate Cortices Of The Aging Brain

Abstract

Aging of the human brain is the common predisposing factor of neurodegenerative diseases. It is the primary risk factor for Alzheimer’s disease and other prevalent neurodegenerative disorders. Proton magnetic resonance spectroscopy (1H-MRS) is a non-invasive clinical tool which can measure in vivo metabolite levels by using proton signals from the metabolites. N-acetyl-aspartate (NAA) and Glx [summation of glutamate (Glu) and glutamine (Gln)] are examples of metabolites which can be measured and quantified by 1H-MRS. NAA is a well-known marker specific for mature neurons. Glx, which has an interesting role in aging, could be used as a central measure for glutamatergic neurotransmission by assessing the entire brain pool of Glu and Gln. Both NAA and Glx have been suggested for measures of energy metabolism, and can serve as neurochemical fingerprints of neural activities in the brain. As the ACC has recently become a focus for aging research because of its implicated role in attention and mood regulation, we evaluated any changes in neural tissue composition with aging, as measured by absolute quantification of metabolites such as choline, creatine, NAA, Glx, and myo-inositol using 1H-MRS at 3 T. The findings and future directions will be discussed from various perspectives.