Shape changes and clumping in nerve cells
Tau is a protein found naturally in the brain that supports healthy nerve cells. In some dementias, like Alzheimer’s disease, tau can change shape and clump together inside nerve cells, which may contribute to cognitive decline.
What is tau protein?
In a healthy brain, tau helps support the internal structure of nerve cells, a bit like scaffolding that holds the cell's shape and helps transport nutrients along its length.
In some brain conditions, tau can change shape and become 'sticky', causing it to clump together inside nerve cells. These clumps are sometimes called neurofibrillary tangles. When tau builds up in this way:
- it no longer supports the nerve cell properly
- nerve cell communication is disrupted
- the affected cells can become damaged over time.
Tau changes are seen in Alzheimer's disease and are also the main brain change in some other conditions, including frontotemporal dementia and some forms of primary progressive aphasia.
Why is tau important in dementia?
Tau build-up may be associated with:
- disrupted transport of nutrients within nerve cells
- impaired communication between nerve cells
- loss of the internal support structure nerve cells rely on
- memory, language or behaviour changes, depending on which part of the brain is affected
- progressive damage to affected brain regions.
In Alzheimer's disease, tau changes often appear alongside amyloid changes, and the two are thought to interact as the disease progresses. In other conditions, such as frontotemporal dementia, tau changes can occur on their own, without amyloid being involved.
Related topics
- Alpha-synuclein
- Amyloid
Common patient questions
Tau is strongly associated with Alzheimer's disease, and tau tangles are one of the key changes seen in the brain. However, Alzheimer's disease is thought to result from an interaction between tau, amyloid and other biological changes, rather than tau alone.
Amyloid plaques:
- involve amyloid-beta protein
- occur outside brain cells.
Neurofibrillary tangles:
- involve tau protein
- occur inside brain cells.
Both are key biological features of Alzheimer’s disease and are associated with brain damage cognitive decline.
Not currently. However, tau-targeting treatments are an area of ongoing research.