Tau Oligomers Transmit Their Own Pathology

Alzheimer’s Association (http://www.alz.org/braintour/progression.asp)

The pattern of the spread of tau pathology in AD is very consistent and thus can be used to stage the disease. The observation that tau pathology progresses to synaptically connected regions of the brain led to the hypothesis that tau can spread its own pathology, much like an infection. Recent studies show that tau aggregates and specifically tau oligomers isolated from AD brain may act as templates for the misfolding and aggregation of native tau, thereby seeding the spread of the toxic forms of the protein.

Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disease that occurs in association with repetitive traumatic brain injury experienced in sports – such as boxing, football and most recently soccer, and also military combat. The symptoms of CTE may progress slowly over decades to dementia. The tau abnormalities in CTE begin focally, as perivascular neurofibrillary tangles and neurites in the outer cortex and then spread inward to adjacent areas before becoming a widespread degeneration. Although the regions of the brain where tau pathology originates differ in AD and CTE the mechanism of the spread of tau pathology are similar.