Abstract

Many of the most common disorders of old age are characterised by the misfolding of protein molecules and their subsequent aggregation. These aggregates are seen in the brain as plaques in patients with Alzheimer’s disease and similar lesions in patients with Parkinson’s, Huntington’s and motor neurone diseases. The blood vessels in the elderly and the pancreas in diabetics are other common sites of protein aggregation and deposition. This protein misfolding can be infectious and this underpins the dreadful disaster of mad cow disease and CJD . Until recently there were thought to be no other examples. Now, recent research suggests that the common brain disorders of old age may in some respects be infectious – not between people but between neighbouring nerve cells within the brain. This novel approach to understanding the progression of disorders such as Alzheimer’s disease may allow new tests and treatments to be developed.