Alzheimers disease aetiology

Two defining features of Alzheimer’s disease in the brain are amyloid plaques and neurofibrillary tangles (tau). The plaques contain a protein called amyloid-beta, while the tangles are made of a protein called tau. The current, widely accepted amyloid hypothesis regards Alzheimer’s as being due to plaque deposits, whereas the tau hypothesis links the disease to protein abnormalities.
Various Drug companies are developing drugs which target the build-up of amyloid plaques. They have yet to prove successful but are in fairness still in the early days of trials.
However there is no correlation between a patient’s symptoms and the number of plaques they have in the brain, but there is a strong correlation between symptoms and the number of tau tangles.
There are many tangles around the hippocampus, which is involved in new memory formation.
The emphasis has been heavily on plaques being responsible for the symptoms. This is being challenged by scientists speculating that the tangles are the more important
The underlying process must include both plaque and tangle formation. . It is unlikely that these two processes are independent.
Financial Times report 15th July 2008

Martin Eastwood
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