Researchers have discovered the source of cells involved in a phenomenon seen in the brains and spinal cords of people with multiple sclerosis and Alzheimer’s disease. Known as reactive astrogliosis, the condition is characterized by a large number of enlarged star-shaped cells. In multiple sclerosis, these abnormal cells are found in plaques that damage the myelin sheath that surrounds neurons, impairing their signaling function. The new study offers the first firm evidence to date that, at least in the case of multiple sclerosis, the cells are descendant from normal astrocytes.
