Whole brain N-acetylaspartate concentration is conserved throughout normal aging.

Publication Type	Academic Article
Authors	Wu W, Gass A, Glodzik L, Babb J, Hirsch J, Sollberger M, Achtnichts L, Amann M, Monsch A, Gonen O
Journal	Neurobiol Aging
Volume	33
Issue	10
Pagination	2440-7
Date Published	01/14/2012
ISSN	1558-1497
Keywords	Aging, Aspartic Acid, Brain, Brain Chemistry
Abstract	We hypothesize that normal aging implies neuronal durability, reflected by age-independent concentrations of their marker--the amino acid derivative N-acetylaspartate (NAA). To test this, we obtained the whole-brain and whole-head N-acetylaspartate concentrations (WBNAA and WHNAA) with proton magnetic resonance (MR) spectroscopy; and the fractional brain parenchyma volume (fBPV)--a metric of atrophy, by segmenting the magnetic resonance image (MRI) from 42 (18 male) healthy young (31.9 ± 5.8 years old) and 100 (64 male, 72.6 ± 7.3 years old) cognitively normal elderly. The 12.8 ± 1.9 mM WBNAA of the young was not significantly different from the 13.1 ± 3.1 mM in the elderly (p > 0.05). In contrast, both fBPV (87.3 ± 4.7% vs. 74.8 ± 4.8%) and WHNAA (11.1 ± 1.7 mM vs. 9.8 ± 2.4 mM) were significantly higher in the young (approximately 14%; p < 0.0001 for both). The similarity in mean WBNAA between 2 cohorts 4 decades of normal aging apart suggests that neuronal integrity is maintained across the lifespan. Clinically, WBNAA could be used as a marker for normal (hence, also abnormal) brain aging. In contrast, WHNAA and fBPV seem age-related suggesting that brain atrophy may occur without compromising the remaining tissue.
DOI	10.1016/j.neurobiolaging.2011.12.008
PubMed ID	22245316
PubMed Central ID	PMC3328687