The hormone estrogen can sharpen mental performance, and now scientists think they know why. Estrogen may boost the number of connections between brain cells, improving communication in the brain.
The work was presented today (Nov. 17) at the Society for Neuroscience meeting in San Diego.
Previous work has shown that giving estrogen to both animals and people can improve their memory and increase accuracy on tests.
In the new study, researchers at Northwestern University Feinberg School of Medicine treated rat brain cells grown in a dish with a compound similar to estrogen. The compound activated the cells' estrogen receptors, setting off a chain of chemical reactions inside the cells. This in turn caused an increase in the cell's number of dendritic spines — hair-like protrusions on the surface of cells that allow them to talk to each other.
"What this told us is that if you specifically activated the [estrogen receptor] you can potentially increase the amount of information that could go from one cell to another," study researcher Deepak Srivastava said.
It has also been theorized that estrogen treatments could improve symptoms of Alzheimer's and schizophrenia. However, long-term use of estrogen as a therapy has been shown to be problematic — results from the Women's Health Initiative in 2002 found that women taking estrogen to relieve symptoms of menopause were at increased risk for breast cancer , stroke and heart attack.
Because of these risks, researchers have been searching for a way to activate the estrogen receptors without using estrogen itself. This would allow patients to get the benefits of estrogen without the detrimental effects, Srivastava said.
The compound in the study does indeed provide a way to mimic estrogen's effects. However, the researchers noted they cannot be sure whether this compound would also cause side effects similar to those of estrogen.
And much more research needs to be done to determine if the same effect — an increase in communication between cells — would occur inside people's brains.
But the researchers have reason to believe boosting the number of dendirtic spines in Alzheimer's and schizophrenia patients may be beneficial. People with both of these conditions often have a reduced number of these spines in their brains.
The study was funded by the National Institutes of Health, the American Heart Association and the National Alliance for Research into Schizophrenia and Depression.