Alzheimer's Disease

Alzheimer's disease causes loss of brain cells in areas of the brain. Some of the deterioration may be related to a loss of chemical messengers in the brain, called Reference neurotransmitters Opens New Window, that allow nerve cells in the brain to communicate properly.

People with Alzheimer's disease have two things in the brain that are not normal: amyloid plaques and neurofibrillary tangles.

• Amyloid plaques are clumps of a protein called beta amyloid. This plaque builds up around the cells in the brain that communicate with each other.
• Neurofibrillary tangles are made from a protein called tau. Normally, the tau protein helps cells communicate in the brain. In Alzheimer's disease, the tau protein twists and tangles. The tangles clump together, and some nerve cells die, which makes communication in the brain much harder.
• As brain cells die, it shrinks. The damage to the brain eventually causes problems with memory, intelligence, judgment, language, and behavior.

Experts don't know if amyloid plaques and neurofibrillary tangles are side effects of Alzheimer's disease or part of the cause. These plaques and tangles are not found in people who do not have the disease.

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