Plaque blues

摘要

PERFORMING HIS autopsy on Auguste Deter in 1906, Alois Alzheimer noticed three unusual features of her brain. It was at least a third smaller than normal. Many neurons, the nerve cells, had vanished. He also saw abnormal deposits inside the remaining cells, especially in the cerebral cortex, the thin outer layer of grey matter. Between a third and a quarter had been invaded by dense knotty bundles, now known as "neurofibrillary tangles", caused by a build-up of a protein called tau. And across the cortex were deposits of another protein, since identified as beta-amyloid, which collect between neurons and disrupt their functioning.Despite decades of research, Alzheimer's still has no vaccine and no cure. Some fear that the covid-19 crisis will now squeeze the financial and scientific resources available for dementia research. In the pandemic, research has anyway suffered because clinical trials became difficult. Miia Kivipelto, a Finnish neuroscientist who led a study showing how changes in ways of life could slow or arrest cognitive decline, had to suspend her follow-up research. And many people have become wary of seeking diagnosis or help, for fear of infection, or of laying claim to health-care resources needed elsewhere.