Scientists recently discovered a link between brain injuries and Alzheimer’s disease, but a new study from the Oregon Health & Science University in Portland and the University of Rochester Medical Center in New York identified the exact nature of this link.
Alzheimer’s disease and traumatic brain injuries share a common phenomenon in which toxic proteins build up among brain cells due to damage to the brain’s waste removal system.
“The same sort of failure is happening in these two settings, and they seem to have the same results,” said Jeffrey Iliff, an OHSU researcher and co-author of the study published in the Journal of Neuroscience.
This research stems from a study published by the same scientists in 2012 which they explored the protective blood-brain barrier’s mechanism for flushing toxic waste. This process, called the glymphatic system, was first observed in mice.
In 2013, the researchers discovered that the glymphatic system worked more efficiently when the mice were under anesthesia.
The study published several weeks ago showed that a protein called amyloid beta appears in the aging brain, and blockage causes the flushing process to slow.
“The cleaning system fails when the brain ages,” said Iliff. “At the same time, the brain loses its ability to handle amyloid beta.”
The same slowing process occurs after traumatic brain injuries when buildup of the protein tau clogs brain cells. An injury such as a concussion could cause tau to build up, setting the stage for Alzheimer’s.
This discovery could lead scientists to identify people who may be susceptible to Alzheimer’s late in life and treat them in their youth.
“If this is something that is going wrong, then we can fix it,” said Iliff.
Researchers hope to soon find a drug that will slow the development of Alzheimer’s disease after brain injury.