Using Human Brain Tissue in Lab Dishes, Researchers Show Herpes Link to Alzheimer's

A study in Science Advances used human brain tissue to build a three-dimensional quasi-brain model that developed Alzheimer's disease pathology when exposed to the herpes simplex virus HSV-1, reports STAT . Brain-like tissue infected with the virus became riddled with amyloid plaque-like clumps, in addition to developing neuroinflammation and deteriorating electrical signal conductivity. The researchers genetically converted skin cells from human foreskin into neural stem cells, which in four days formed neurons, glia, and other neural structures in the brain. Within days of infection with HSV-1, the quasi-brains' neural cells developed dense, plaque-like globs similar to amyloid plaques typical of Alzheimer's. Inflammation levels climbed and cells cohered into abnormal clumps, and started overproducing the proteins PSEN1 and PSEN2, which raise the risk of Alzheimer's. Moreover, the neurons' ability to send and receive electrical signals sharply dropped. Administering the herpes drug valacyclovir reduced neuroinflammation, purged many of the plaque-like deposits, and improved brain function.