There is encouraging news in the fight against Alzheimer's disease.
Researchers say it seems to spread from brain cell to brain cell.
But those same researchers say it's not a virus or bacteria that is spreading... but a protein.
Researchers also say the findings have good implications for developing treatments.
Two studies on the spread of the protein were done at Columbia and Harvard.
Copyright 2012 KPHO. All rights reserved. CBS News contributed to this report.