Now scientists at Northwestern University have discovered why brain insulin signaling -- crucial for memory formation -- would stop working in Alzheimer's disease. They have shown that a toxic protein found in the brains of individuals with Alzheimer's removes insulin receptors from nerve cells, rendering those neurons insulin resistant. (The protein, known to attack memory-forming synapses, is called an ADDL for "amyloid ß-derived diffusible ligand.")
With other research showing that levels of brain insulin and its related receptors are lower in individuals with Alzheimer's disease, the Northwestern study sheds light on the emerging idea of Alzheimer's being a "type 3" diabetes.
http://www.sciencedaily.com/releases/2007/...70926113835.htm