Alzheimer’s Disease Pathology

What is actually happening to the brain in Alzheimer’s disease?

The classic signs of Alzheimer’s disease are amyloid plaques, neurofibrillary tangles and inflammation.

In recent years, with the help of research sponsored by Cure Alzheimer’s Fund, a scientific consensus has started to emerge about how Alzheimer’s disease originates and develops in a vicious cycle of Abeta peptide accumulation, nerve cell death and inflammation, followed by even more nerve cell death. Genetic and environmental factors can trigger Abeta accumulation, tau tangle formation, and inflammation. Once one part of the pathology is in place, it then acts as a trigger for the other parts — for example, Abeta accumulation can lead to increased inflammation, and vice versa. This vicious cycle continues, causing more and more damage and nerve cell death. Eventually, this damage becomes so severe that the patient begins to experience a loss in cognitive function.

This model gives a simplified illustration of the emerging consensus and the three basic strategies for intervention:

  1. An early-phase intervention, inhibiting the production of the Abeta protein, and/or clearing it from the brain after it forms.
  2. A mid-phase intervention that would inhibit the formation of Tau tangles and protect neurons from undue stress.
  3. A late-phase intervention that would fight inflammation and thus slow down or even stop the disease process.