Estrogen Activation Plays Role in Memory

A recent study looks at the role that loss of estrogen plays in menopause and how it can increase a woman's risk for dementia and Alzheimer's disease. Yet on the other hand, hormone replacement therapy can cause harmful side effects.

Knowing the exact mechanism of estrogen activation in the brain can help lead to new targets for drug development that may provide middle-aged women with cognitive benefits for hormone replacement therapy without increasing their risk for cardiovascular disease or breast cancer, according to background information from the study.

Lead study author Karyn Frick, the professor of psychology at the University of Wisconsin-Milwaukee (UWM), works to uncover details regarding estrogen's role in the complex cellular communications regarding the function of memory and the role of the hormone.

"The receptor mechanisms that regulate estrogen's ability to enhance memory are still poorly understood," said Frick, via a press release. "With this study, we've begun to sort out several of the key players needed for estrogens to mediate memory formation."

As the amount of estrogen that effects the hippocampus deteriorates with the age of Alzheimer's disease, reserachers have found that each of the two known estrogen receptors quickly activate a specific cellular pathway that's necessary for memory formation in the hippocampus of female mice. However, this only happens with a certain glutamate receptor, known as mGluR1.

The study shows that when the glutamate receptor is blocked, the cell-signaling protein ERK is unable to be activated by estrogen, 17β-estradiol.

As this activation is important for memory formation, estradiol failed to enhance memory among mice in which mGluR1 was blocked.

His team also found evidence that estrogen receptors and mGluR1 physically interact via the cell membrane, allowing estradiol to influence memory formation with seconds to minutes that provide evidence of rapid signaling that's initiated by interactions that are essential to enhance memory regulation via the hippocampus.

"Our data suggesting that interactions between estrogen receptors and mGluR1 at the cell membrane are critical for estradiol to enhance memory provides important new information about how estrogens regulate memory formation," Frick adds, via the release. "Because membrane proteins are better targets for drug development than proteins inside the cell, these data could lead to a new generation of therapies that provide the cognitive benefits of estrogens without harmful side effects."

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More information regarding the study can be found via the Journal of Neuroscience.