The tau protein stabilizes the structure within the nerve cells that the cells need to divide, carry substances and use for support. If this protein becomes abnormal, it will form twisted fibers inside of the nerve cells and destroy them, which causes various neurological diseases. An abnormal tau protein can cause tangles inside the nerve cells of a person with Alzheimer's and swollen nerve cells in people who have Pick's disease or corticobasal degeneration.
What is a Tau Protein?
The tau protein is found in all nerve cells and stabilizes the microtubules of the cell; that is, it stabilizes the structure that supports the cell, carries substances within the cell and helps the cell divide. In an article in the April 2004 issue of “Physiological Reviews,” Jesus Avila states if phosphorus attaches to several places on the tau protein, the protein will break off the microtubules and form twisted fibers. These twisted, abnormal fibers can then harm the nerve cells and lead to several disorders, including Alzheimer's disease, Pick's disease and corticobasal degeneration.
Alzheimer's Disease and the Tau Protein
Over 65 percent of the elderly population with dementia has Alzheimer's disease, according to “The Merck Manual for Healthcare Professionals.” People with Alzheimer's disease have lost nerve cells, areas in the brain where a beta amyloid protein has accumulated and causes damage and areas where the brain itself has wasted away. They also have twisted fibers of the tau protein, called neurofibrillary tangles, inside many of the remaining nerve cells in the brain. Abnormal tau protein may also be in the cerebrospinal fluid that circulates and cushions the brain and spinal cord.
Pick's Disease and the Tau Protein
Pick's disease is a rare disease in which the patient's the behavior changes; problems with thinking and speech start at a younger age than in those with Alzheimer's disease. In this disorder, swollen nerve cells, called Pick cells, and substances inside of cells called Pick bodies are made of abnormal tau protein. Similar to Alzheimer's disease, people with Pick's lose nerve cells and have shrunken areas in the brain, but the affected areas are different, writes Victor Valcour, M.D., Adjunct Clinical Assistant Professor of Geriatrics in Neurology at the University of California in “Hazzard’s Geriatric Medicine and Gerontology.”
Corticobasal Degeneration and the Tau Protein
Corticobasal degeneration is a rare disease that affects the middle-aged and the elderly, per Roger Simon, M.D., Director of Neurobiology Research at Legacy Health Systems in “Clinical Neurology.” Initially, people with this disorder have swollen nerve cells in the cortex and basal ganglia areas of the brain, but the cells will then degenerate. The nerve cells are destroyed because there are filaments inside of them that contain twisted fibers of the tau protein. As a result, people with this disorder will be very unstable when they walk or stand still.