Study: Plaques Tied to Alzheimer's Shut Down Genes Critical to Memories

Six genes critical to making memories tend to shut down in lab mice when they develop plaques in their brains that are have been linked to Alzheimer's disease, according to University of South Florida researchers.

In a study that looked at both mice and humans, the researchers found that a buildup of plaques formed by the beta-amyloid protein was accompanied by a significant suppression of brain cell genes known to regulate memory and learning.

Reporting in the Journal of Neuroscience, the researchers said they discovered six genes in the brain tissue of the sick mice that were significantly suppressed in the presence of plaques. The genes are called Arc, Zif268, NR2B, GluR1, Homer-1a and Nur77/TR3.

Animals missing the first two "cannot remember anything," said Dave Morgan, the lead researchers.

Interestingly, the the study showed an abnormal reduction in memory genes in mice only in brain areas where beta-amyloid plaques occurred. Brain areas free of plaques showed normal gene levels.

After confirming their results of their animal study, the researchers turned to tissue samples from the brains of patients who had died with Alzheimer's, and again found the six learning and memory genes muted in cells affected by beta-amyloid plaques.

However, in the human tissue, a host of other brain genes also were suppressed.

But Morgan said the study could potentially lead to a new approach to fighting Alzheimer's.

A variety of current trial are focused on preventing the buildup of the plaques, or cleaning them up. Another possibility Morgan said, might be development of new types of drugs to try to maintain normal levels of memory genes even when plaques cannot be eliminated.

Other sources: Journal of Neurosciencer