In an experiment reported in the journal Nature Neuroscience, a single dose of an antibody appears to reverse memory loss in mice, providing a stepping stone toward an Alzheimer's disease vaccine.

A team at Lilly Research Laboratories in Indianapolis, Washington University in St. Louis, and Université Louis Pasteur in France are reporting steady progress using an antibody called m266 in mice genetically engineered to develop a syndrome similar to Alzheimer's.

"To our surprise, we found that the antibody actually could improve memory in these mice very quickly without even having an effect on the amyloid plaque," says Dr. Steven Paul of Eli Lilly, a leading investigator in the study. What that says is, perhaps in the early stages of this disease, the plaque may not be the only bad actor in the brain."

"This is a good news story," continues Dr. Paul. "For the First time in history, we are now on the verge of using the scientific knowledge that we know about this disease to provide more than just symptomatic treatment. I think that within the next three to six years, we will be able to test this hypothesis."

Alzheimer's disease affects about 4 million Americans.