ALZHEIMER'S DISEASE: Today, more than five million Americans have Alzheimer's, a fatal brain disease that progresses over time. It is the seventh-leading cause of death in the United States. As brain cells in Alzheimer's patients die, memory, thinking and behavior problems arise -- Alzheimer's is the most common form of dementia.

TAU VACCINE: While there is currently no way to prevent or reverse Alzheimer's disease, an experimental vaccine that targets tangles of tau protein shows promising results in mice. Researchers at New York University found the vaccine slowed dementia when injected into mice bred to develop abnormal tangles of tau. Compared to the controls, the immunized mice had better behavioral and motor function at five and eight months. The vaccine works by making antibodies in the mice that cross the blood-brain barrier and attack tau.

WHAT IS TAU? Tau is a soluble protein found in healthy brain cells. However, in Alzheimer's, tau abnormally phosphorylates, causing tangles to form in neurons of the cerebral cortex and temporal lobe regions like the hippocampus and amygdala.

NOT THE FIRST ALZHEIMER'S VACCINE: Along with tau protein, beta-amyloid protein is also well-associated with Alzheimer's disease, having been the focus of many previous studies. A vaccine targeting beta-amyloid protein showed promise in animal studies, but it caused serious health consequences when tested on humans. Twelve of the 360 immunized patients developed severe inflammation of the central nervous system, causing researchers to cease testing. Researchers say a treatment that targets both proteins -- tau and beta-amyloid -- may provide the most promising hope for Alzheimer's patients.

STEM CELL THERAPY: Researchers at the University of Central Florida are studying another way to treat Alzheimer's -- with stem cells. The scientists are using a newly discovered compound, phenserine, to reduce the amount of amyloid-precursor protein (APP). APP is linked to Alzheimer's disease through it's role in plaque formation which lead to the death of brain cells. By reducing APP, phenserine allows stem cells to regenerate into the memory neurons Alzheimer's disease destroys.

Kiminobu Sugaya, Ph.D., a professor of molecular biology at the University of Central Florida, is now studying if combining phenserine with another compound he created, NBI-18, may be an even more effective way to grow new neurons in Alzheimer's patients. Dr. Sugaya's compound increases brain stem cells by 600 percent. Increasing neurons may be important in improving brain function, especially in people with neurodegenerative diseases.