Narrator: This is Science Today. When researchers look under the microscope at the brain cells of patients with frontotemporal dementia, or FTD, they see a variety of possible patterns of brain damage. Dr. Adam Boxer of the University of California, San Francisco's Memory and Aging Center says the common factor is that different nerve cells and the connections between the nerve cells die out.
Boxer: But in some of the cells that are preserved, we can see little accumulations of proteins. In frontotemporal dementia there are a couple characteristics, what we call inclusions, these little balls of protein. We call them inclusions because they're included inside nerve cells and they're not normally supposed to be there.
Narrator: These proteins are most commonly called tau, which are normally part of the nerve cells, but in FTD and in Alzheimer's disease, something goes wrong with the tau.
Boxer: It starts to stick together and clump together and the cells shrivel and they become deformed and eventually we think that what happens is that in an attempt to protect itself from this abnormal tau, the cells form these little balls or inclusions.
Narrator: For Science Today, I'm Larissa Branin.