Knowing the exact mechanism of estrogen activation in the brain could lead to new targets for drug development that would provide middle-aged women the cognitive benefits of hormone replacement therapy without increasing their risk for cardiovascular disease or breast cancer.
Karyn Frick, professor of psychology at the University of Wisconsin-Milwaukee (UWM), said that the receptor mechanisms that regulate estrogen's ability to enhance memory are still poorly understood.
The researchers found that each of the two known estrogen receptors rapidly activate a specific cellular pathway necessary for memory formation in the hippocampus of female mice, but only if they interact with a certain glutamate receptor, called mGluR1.
The study revealed that when this glutamate receptor is blocked, the cell-signaling protein ERK cannot be activated by the potent estrogen, 17 beta-estradiol. Because ERK activation is necessary for memory formation, estradiol failed to enhance memory among mice in which mGluR1 was blocked.
Frick's team also found evidence that estrogen receptors and mGluR1 physically interact at the cell membrane, allowing estradiol to influence memory formation within seconds to minutes.
Collectively, the data provide the first evidence that the rapid signaling initiated by such interactions is essential for estradiol to enhance memory regulated by the hippocampus.
The research has been published in the Journal of Neuroscience.
--ANI (Posted on 19-09-2013)