Researchers Uncover How Alzheimer's Spreads
Last updated: Feb 02, 2012
For all the research on Alzheimer's disease taking place, true breakthroughs are relatively rare. Here's a big one: Scientists have finally figured out how Alzheimer's disease advances within the brain. It spreads like an infection, reports The New York Times, moving from brain cell to brain cell, like a virus or bacteria. In this case, though, it's a distorted protein -- tau -- that wreaks havoc.
Knowing this, scientists may be able to develop an antibody or other agent that can bring this cell-to-cell transmission to a sudden halt.
Scientists at Columbia and Harvard made the discovery using genetically-engineered mice. It's been known for some time that tau-filled cells are first found in the area of the brain that stores memories, then somehow the disease slowly travels to the areas that involve remembering and reasoning.
Researchers wondered but, until now, couldn't figure out whether this ongoing cell death and destruction happened because of a "bad neighborhood" created by another protein found in the brains of Alzheimer's patients, beta amyloid. Beta amyloid clumps outside the brain cells and seemed to set the stage for a gradual accumulation of tau in each cell to finish them off. (Some researchers called tau "the executioner.")
This research shows that's not what happens. "That is what is different between these papers and all the others," John Hardy, an Alzheimer's researcher at University College London (who was not involved in these studies) told the NYT. "It isn't a bad neighborhood. It is contagion from one neuron to another."