Human tau seeds trigger disease-specific shapes in mouse brains, new study finds

Human tau seeds from Alzheimer’s disease (AD) and corticobasal degeneration (CBD) induced mouse tau to misfold into disease-specific 3D structures, according to a Nature study. Researchers injected minute amounts of tau extracted from postmortem human brains into healthy mice. Within a week, the human seeds disappeared, but the mice’s own tau continued forming fibers with precise folds matching the original seeds over nine to twelve months.

High-resolution cryo-electron microscopy confirmed that AD seeds prompted mouse tau to adopt the characteristic paired helical filament structure, while CBD seeds induced the corresponding CBD fold. The structural identity of each seed strain was retained as tau propagated through the brain.

The study also found cell-type differences: AD seeds caused tau accumulation mainly in neurons, whereas CBD seeds produced clumps in both neurons and glial cells, mirroring patterns seen in human patients. These findings support the prion-like seeding hypothesis for tau and suggest that distinct tau folds act as strains with stable structural identities, informing future therapeutic and diagnostic strategies.