disease is a brain condition which causes a progressive decline in memory, learning, thinking and organizing skills over time, particularly affecting people in old age. It is the most common cause of dementia, a general term which is used for memory loss and other cognitive abilities which tend to affect our daily life.
In 1906, German physician Dr. Alois Alzheimer first described Alzheimer's. He studied changes in the brain tissue of a woman who had died of a weird mental illness. On examining her brain, he found many abnormal clumps between the tissues (now called amyloid plaques).The first sign of Alzheimer's disease is usually minor memory problems. As the condition develops, memory problems become more severe and further symptoms can develop, such as:
•confusion and disorientation
•problems with speech and language
•impulsive and abrupt behavior
•hallucinations and delusions
Finding the actual cause of Alzheimer's is still something which scientists need to unravel but most of the studies are focused on the role of two proteins :
• Plaques
Plaques are deposits of a protein fragment called beta-amyloid that build up in the spaces between neurons present in the brain. When these fragments clump together, they seem to have a toxic effect on neurons and primarily disrupt the communication between them.
• Tangles
Tangles are twisted fibers of another protein called tau that build up inside cells. These tau proteins change shape and form structures called neurofibrillary tangles which disrupt the transport system.
The beta-amyloid protein involved in Alzheimer’s comes in several different molecular forms with different structures. It is formed from the breakdown of a larger protein called amyloid precursor protein. One form which is beta-amyloid 42, is said to be especially toxic. In the brain with Alzheimer's, abnormally high levels of this naturally occurring protein clump together to form plaques that collect between neurons and disrupt cell function. Research is ongoing to better understand how, and at what stage of the disease, the various forms of beta-amyloid influence Alzheimer’s.
No cure has been discovered yet for treatment of this brain condition. Some drugs like N-methyl D-aspartate (NMDA) have been found to reduce the symptoms.
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