Quantitative 1H and 31P MRS of PCA extracts of postmortem Alzheimerʹs disease brain

Several previous studies have shown metabolic abnormalities in perchloric acid extracts of postmortem Alzheimerʹs disease (AD) brain by both proton (1H) and phosphorus-31 (31P) magnetic resonance spectroscopy (MRS). In all of these studies the results were expressed in relative terms, in units of mol percent. The results of this study, expressed in the absolute units of μmol/g wet weight, verify the previous 1H and 31P MRS studies. Absolute increases were found for myo-inositol, aspartate, image-glutamate, alanine, phosphocholine, and the phosphodiesters,. Absolute decreases were found for phosphoethanolamine and N-acetyl-l-aspartate. Many of these changes also were observed in non-AD dementia brain extracts, but changes in myo-inositol, inositol-1-phosphate, aspartate, and image-glutamate appeared to be more specific for AD in extracts of many brain areas. These results suggest that compounds related to membrane degradation and excitatory neurotransmission increase in Alzheimerʹs disease while compounds related to neuronal integrity and inhibitory neurotransmission are decreased.