During Alzheimer’s disease, a substance called beta amyloid clumps together in the brain forming plaques, which block the circuitry. These changes in the brain often begin long before patients become confused and forgetful. Over a century since its first description by German psychiatrist Alois Alzheimer – born this day in 1864 – scientists are striving to improve early diagnosis. Pictured are brain scans from elderly individuals given a radioactive tag that homes to beta amyloid. In healthy brains (left), there is virtually none (blue). But in full-blown Alzheimer's (right), a high density of plaques light up in orange and red. Some individuals (middle) don't yet display any outward signs of dementia, but an increase in green reveals a worrying accumulation of beta amyloid. Earlier discovery of Alzheimer's could mean patients will get more benefit from drugs that delay its progression.
Written by Emma Stoye
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.