Amyloid beta protein levels affect memory

ST. LOUIS, Nov. 12 (UPI) -- Too much amyloid beta protein is linked to Alzheimer's disease, but not enough in healthy brains can cause learning problems, U.S. scientists found.

Researchers at Saint Louis University in Missouri, led by Dr. John Morley, found young, healthy mice receiving low doses of the amyloid beta protein show improvement in recognizing objects and successfully navigating a maze. Conversely, mice receiving a drug blocking amyloid beta protein had learning impairment.

The study, published in the Journal of Alzheimer's Disease, suggests Alzheimer's disease may actually be too much of a good thing-- amyloid beta -- that in healthy brains actually enhances learning and memory.

"You can't totally wipe out amyloid beta protein. If you do this, you are going to create dementia," Morley said. "In treating Alzheimer's disease, we have to be careful not to lower amyloid beta too much because it will cause as many problems as if you had an excess of amyloid beta protein."

Morley said the findings are important in developing drugs to treat Alzheimer's disease.