Pathology of Alzheimer's Disease

There are many current theories as to what triggers the onset of Alzheimer's Disease. There seem to be many contributing factors laying at the root of this disease, and the acquisition of Alzheimer's seems to have both environmental and genetic foundations. Regardless of the cause, the gross pathology of Alzheimer's dementia remains the same: toxic levels of amyloid protein build up in the brain, and destroy those regions next to the accumulation sites. This particular section of our Alzheimer's Web Page will look more in depth at the structure and production of amyloid protein in the brain of Alzheimer's patients.

Dating back to Alois Alzheimer's 1907 initial description of the disease, are the characteristic silk-like senile plaques and neurofibrillary tangles and threads that accumulate within the gray matter of the cerebral cortex and cerebral nerve cells of Alzheimer's patients. Composed of highly indigestible amyloid fibers, Alzheimer's patients are unable to break these fibers down. The accumulation of these fibers leads then to the production of the brain lesions characteristic of Alzheimer's Disease (Glenner). The plaques accumulate to neurotoxic levels, compressing those nerve fibers that lie in their path, effectively destroying these regions of the brain (Glenner). This destruction of cerebral tissue then causes the behavioral changes that we associate with Alzheimer's dementia. In extremely progressed cases, these amyloid fibers will aggregate around blood vessels, causing a structural weakening to occur in the vessels and a subsequent leakage of blood serum into the cerebral space. If leakage is great, intercerebral hemorrhage and stroke are likely to occur (Glenner).

The following images were taken from a University of Utah CNS Pathology Archive, and show what a researcher might find after taking a section of brain from an Alzheimer's victim:

Amyloid Plaque

Neurofibrillary Tangle

For more information the various types of plaques and tangles, and their implications in Alzheimer's disease, we suggest checking out the following link:

more on plaques and tangles

The progression of Alzheimer's Disease hinges on these accumulations of plaques and tangles and the subsequent cerebral degradation that follows. Consequantly, this cerebral degredation then leads to the symptomolgy expressed by Alzheimer's patients..

To find out more information about plaques, tangles and amyloid protein, we invite you to check out a couple of really good links provided by the Alzheimers Association Web Page. Don't forget to use your toolbar to come on BACK here (there is not a link) once you've had your fill.

Welcome Back! As you have read, the presence and accumulation of amyloid protein is central to the development of Alzheimer's. To truly begin to understand Alzheimer's, then, we must look further at how this protein is produced in our bodies. The following link will give you even more details on amyloid protein .

Go on to the Genetic Aspects of Alzheimer's

Look at Current Treatment Methods for Alzheimer's

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