Figure 4.

The expanded age-dependent hypothesis of Alzheimer's disease. The three tenets of the new hypothesis are displayed in bold type on blue ovals and numbered for clarity. The interconnected amyloid deposition cycle is displayed in a similar fashion. Added to the diagram are a few of the cell biological and biochemical processes that play significant roles in Alzheimer's disease. Blue arrows (single- and double-headed) provide a small bit of the interactive nature of the various events. For clarity, some events are illustrated twice (e.g., “autophagy defects”). The light blue text and arrows at the top of the diagram are meant to symbolize the possibility discussed in the text that other late-onset neurodegenerative diseases may begin from the same origin as Alzheimer's disease, but differ based on their initiating injury and downstream response.