Scientists may have found how Alzheimer's spreads through the brain
Researchers at University of Utah Health, publishing in the journal Cell, report that a brain protein called Arc helps toxic tau move from diseased neurons into healthy ones. In mice without Arc, the spread of tau almost vanished. The same Arc and tau packages also appeared in hu
Alzheimer's is driven by toxic tau protein that clumps into tangles and then spreads to new regions of the brain. Researchers at University of Utah Health, in a study published in the journal Cell, identified a likely courier: a protein called Arc that normally helps neurons communicate by packing signals into tiny extracellular vesicles. Toxic tau attaches to Arc inside those sacs and travels from a sick neuron into a healthy one. In mice engineered without Arc, the transfer almost disappeared, and the same Arc-and-tau packages were found in human brain tissue. Arc also has a protective side, helping sick cells expel excess tau, so deleting it makes those neurons die faster. That points to a sharper target: intercepting the toxic vesicles after they leave a dying cell but before they reach a healthy one. Senior author Jason Shepherd and first author Mitali Tyagi caution that most of the work is in mice and that a therapy remains far off.