Membrane Lipids, Selectively Diminished in Alzheimer Brains, Suggest Synapse Loss as a Primary Event in Early‐Onset Form (Type I) and Demyelination in Late‐Onset Form (Type II)

: Major membrane lipids were quantified in frontal (Brodmann area 9) and temporal (Brodmann areas 21 and 22) cortices, caudate nucleus, hippocampus, and frontal white matter of 12 cases with Alzheimer's disease (AD) type I (early onset), 21 cases with AD type II (late onset), and 20 age‐matched controls. The concentration of gangliosides—a marker for axodendritic arborization—was reduced to 58–70% of the control concentration in all four gray...