Using gene therapies that overexpressed two types of estrogen receptors in the brain, investigators at University of Florida Health say they found that one of them--combined with added estrogen--reinstated memory in aging rats, pointing to a possible approach in preventing the memory-stealing disease among women who are most at risk. The findings are reported in the current issue of The Journal of Neuroscience.
The researchers say that hormone replacement therapy begun at menopause has protective qualities that maintain plasticity in the brain--the connectivity of cells needed for learning. But around the age of 65 that protective quality of HRTs wanes, making women more vulnerable to Alzheimer's.
As a result, they decided to see if gene therapies that overexpressed two different estrogen receptors, the alpha and beta receptors in the hippocampus, could play a therapeutic role, testing it on rat models. They also used a control gene in the population of 72 rats and followed up with estrogen therapy or a placebo.
Only the alpha receptor approach demonstrated a return of plasticity in the brain. And this new direction could eventually lead to a therapy that can improve cognition without hormone replacement therapy.
"In the short term, this finding helps us understand how estrogen rescues memory and keeps the brain young and plastic," Foster said. "In the long term, this finding may eventually allow us to bypass estrogen and target the receptor or brain plasticity mechanisms directly."
- here's the release