Brain gangliosides in Alzheimer's disease.

The results demonstrated a statistically significant decrease of ganglio-series gangliosides (GTlb, GDlb, GDla, GMl, nmol lipid-bound sialic acid/mg DNA) in frontal and temporal cortex and basal telencephalon of brains with Alzheimer's disease (AD) in comparison to control brains (P less than 0.05). In addition, frontal and parietal cortex also showed somewhat elevated concentrations of simple gangliosides (GM2, GM3, GM4). Changes in gangliosides in seven regions of human brains with AD analyzed, except of the temporal cortex, did not significantly differ in the "a"/"b" ratio (GDla + GMl/GDlb + GTlb) of ganglioside composition in comparison to control brains. In temporal cortex, an decrease of "a"/"b" ratio on the accounts of more decreased GDla and GMl than GDlb and GTlb was found. A decreased concentration of ganglio-series gangliosides in AD probably correlates with degeneration of cortical neurons. However, elevation of simple gangliosides in frontal and parietal cortex might correlate with an accelerated lysosomal degradation of gangliosides and/or astrogliosis occurring during neuronal death.