Introduction
Alzheimer's disease is a progressive, degenerative disease of the brain. It was first described by Alois Alzheimer in 1906. It is the most common form of dementia and accounts for 50% - 60% of all cases Dementia is a general term for progressive degenerative brain syndromes which affect memory, thinking, behavior and emotion. It is not a normal part of aging. Although each person experiences dementia in their own way, eventually those affected are unable to care for themselves and need help with all aspects of daily life. Currently, there is no cure for Alzheimer's disease.

What causes Alzheimer's disease?
Currently, the cause of Alzheimer's disease is not very well understood. During the course of Alzheimer's disease, nerve cells die in particular regions of the brain. The brain shrinks as gaps develop in the temporal lobe and hippocampus, which are responsible for storing and retrieving new information. This in turn affects people's ability to remember, speak, think and make decisions. The production of certain chemicals in the brain, such as acetylcholine, is also affected. It is not known what causes nerve cells to die but there are characteristic appearances of the brain after death. In particular, 'tangles' and 'plaques' made from protein fragments are observed under the microscope in damaged areas of brain. This confirms the diagnosis of Alzheimer's disease.

What is BNL doing to understand Alzheimer's disease?
Currently, researchers at BNL are working in collaboration with scientists from Switzerland to understand why plaques and tangles form in the brains of Alzheimer's disease patients and how these plaques and tangles influence the death of nerve cells in the brain. They are also studying plaques and tangles found in other organs of the body, such as pancreas, ovary and testis, to see whether these structures are related to those found in the brain.

How is synchrotron light used?
At the NSLS, a combination of ultraviolet and infrared light is used to study the structure of the proteins involved in the formation of plaques and tangles in the brain. Fluorescence microscopy is used to identify the plaques & tangles, and infrared imaging is used to determine their structures within brain tissue. At the same time, infrared imaging is also used to study the health of the nerve cells surrounding the plaques and tangles in the brain tissue.

How will this research help Alzheimer's disease patients in the future?
Understanding the structures of the plaques and tangles in Alzheimer's diseased brain may help to develop ways of preventing them from forming, thus preventing progression of the disease.  In addition, identification of plaques & tangles in other organs may provide a biopsy method for early diagnosis of Alzheimer's disease in the future.

For more information, you can contact:
Dr. Lisa Miller
National Synchrotron Light Source
Building 725D
Brookhaven National Laboratory
Upton, NY  11973
Phone: (631) 344-2091
Email: lmiller@bnl.gov