Normal brain aging is associated with changes occurring at all levels. This study investigates age-related differences in the brain intracellular microenvironment by comparing the apparent diffusion coefficients (ADC) and apparent transverse relaxation time constants (T2) of 5 neurochemicals (i.e., total N-acetyl-aspartate, total creatine, total choline, glutamate, and myo-inositol) between young and older adults. Thirty-two young healthy adults (18–22 years) and 26 older healthy adults (70–83 years) were recruited. Three brain regions were studied at 3 T: prefrontal, posterior cingulate and occipital cortices. ADC and T2 were measured using stimulated echo acquisition mode and localization by adiabatic selective refocusing sequences, respectively. This study shows that the diffusivities of several neurochemicals are higher in older than in younger adults. In contrast, shorter apparent T2 values for several metabolites were measured in older adults. Age-related difference in ADC and apparent T2 of metabolites seem to be region-specific. Furthermore, this study shows that it is feasible to observe age-related differences in the cellular microenvironment of neurochemicals in the normal aging brain.
|Original language||English (US)|
|Number of pages||8|
|Journal||Neurobiology of Aging|
|State||Published - Nov 2020|
Bibliographical noteFunding Information:
The authors would like to thank Andrew Oliver and Sarah Bedell for study coordination, Akshay Patke for neuropsychological testing, and Emily Kittelson and Andrea Grant, PhD, for technical support. This work was supported by funding from the National Institutes of Health grants ( R21AG045606 , P41 EB015894 , P30 NS076408 ).
- Magnetic resonance spectroscopy