The hormone estrogen is important in keeping the brain healthy and allowing memories to form, but its effects lessen as women age. A team of researchers from the University of Florida is looking to improve the situation, testing a gene therapy method to return memory function in laboratory rats.
Estrogen plays a big role in thebrain, helping to maintain the organ's ability to form and maintainconnections (something known as "plasticity") which in turn facilitates the process of learning and retaining memories. Loweredestrogen levels can lead to a loss of brain plasticity, causingpatients to have problems with memory.
As women get older, the amount ofestrogen in their bodies drops significantly, in a transition periodknown as menopause. From the onset of menopause, which usually beginsin the early 50s, hormone replacement therapy is effective inprotecting the brain against damage, including neurodegenerative conditions such as Alzheimer's disease, up until around age 65.However, after that point, the technique stops being effective.
The University of Florida team turnedto gene therapy in an attempt to tackle the issue, increasing theexpression of two estrogen receptors in the hippocampus – a part ofthe brain that's central to forming and maintaining memories.
They conducted tests on a large sample of aging laboratory rats, with 72 animals split into two sets of three groups– one for each overexpressed receptor and one control group. One setof groups was tested with the gene therapy treatment alone, whileanother set received estrogen alongside the therapy. Of the sixgroups, significant improvements in memory were observed in thememories of one of the receptor plus estrogen groups, referred to asthe alpha receptor group.
While only an early step, the studymarks an important breakthrough in the development of alternatives tohormone replacement treatments.
"In the short term, this findinghelps us understand how estrogen rescues memory and keeps the brainyoung and plastic," says team member Professor Thomas Foster. "Inthe long term, this finding may eventually allow us to bypassestrogen and target the receptor or brain plasticity mechanismsdirectly."
The researchers plan to continue theirwork, looking to better understand and ultimately harness the powerof the alpha receptor. In the meantime, they published their findings in The Journal of Neuroscience.
Source: University of Florida
