The first of them will hit age 65 in 2011. About 10 percent of the nation's population over 65 has Alzheimer's. Researchers are focusing on two physical manifestations of the disease in the nervous system. Most are looking at excess brain plaque, called beta amyloid, which shows up in large amounts in Alzheimer's patients. Scientists are divided on whether the tau causes the plaque or vice versa.
Beta amyloids grow between nerve cells, where they block communication and even kill cells.
In a sense, they are the brain's version of cholesterol. The plaque consists of tiny fragments of a long protein that is normal in the body. Alzheimer's patients have many more of those fragments than people without the disease. Recent research has identified two enzymes that cut the long protein into the tiny fragments that clog cells. Scientists are trying to determine how to block the enzymes, Morrison-Bogorad said.