N-acetylaspartate and N-acetylaspartylglutamate levels in Alzheimer's disease post-mortem brain tissue.

The tissue concentrations of two related amino acid derivatives, N-acetylaspartate (NAA) and N-acetylaspartylglutamate (NAAG) were determined in autopsy hippocampus, amygdala, cerebellar cortex and olfactory bulb of Alzheimer's disease patients and age-matched non-demented controls, using reverse-phase HPLC and fluorescence detection after precolumn derivatisation with the fluorophore 2-aminoanthracene. In Alzheimer's disease, NAA and NAAG concentrations were significantly reduced in the hippocampus (by 38 and 24%) and the amygdala (by 28 and 22%), but not in the olfactory bulb and the cerebellar cortex. These results indicate that the concentrations of NAA and NAAG are selectively decreased in brain areas affected by pathology in Alzheimer's disease.