Secrets of the brain

Secrets of the brain

New Alzheimer’s research dashes notion of benign brain plaque

Todd Golde, M.D., Ph.D.

The time may have come to scrub the idea that brain plaque — deposits of protein that clog passages between brain cells — might not be all that bad.

UF researchers have discovered that people with no signs of dementia during their lives, even though their brains contained the debris typical of Alzheimer’s disease, probably would have experienced health problems had they lived longer, according to a study in the open access journal Alzheimer’s Research & Therapy.

Scientists suspect patients who experience relatively few cognitive problems even with amyloid beta protein accumulating in their brains — the hallmark of Alzheimer’s disease — might collect a less toxic form of the so-called brain plaque.

But UF College of Medicine scientists with colleagues from the Mayo Clinic in Jacksonville found few differences when they compared the postmortem brain tissue of Alzheimer’s patients with that from people who accumulated plaque without symptoms, a condition known as pathological aging.

“It will be important to understand the differences between these two neurodegenerative pathologies in treatment and prevention efforts,” said Todd Golde, M.D., Ph.D., director of the UF’s Center for Translational Research in Neurodegenerative Disease.

Alzheimer’s disease is characterized by severe loss of neurons in brain regions important for learning and memory because of overproduction of amyloid beta protein. In a healthy brain, these protein fragments are broken down and eliminated. But when they accumulate, scientists believe amyloid plaque interferes with the brain’s ability to generate new cells and contributes to tangles — twisted masses of protein fibers within brain cells.

Experimental models suggest therapies that target these proteins may prevent or delay disease development. Without treatment or prevention breakthroughs, a projected 7.7 million patients in the U.S. will have Alzheimer’s by 2030, according to the Alzheimer’s Association. That number will grow to between 11 million and 16 million by 2050. — John Pastor