Clegg and colleagues used recently developed "gene silencing" techniques to inactivate a set of switches in the brains of female rats. The switches are estrogen receptors, which normally respond to estrogen. Clegg and colleagues removed these receptors from a specific part of the brain that controls food intake, energy expenditure, and fat distribution.
What happened? The rats' bodies slowed down. They had less energy. And they began to gain weight, even though they weren't given any extra food.
"Women are protected from these negative consequences as long as they carry their weight in their hips and saddlebags," Clegg says in a news release. "But when they go through menopause and the body fat shifts to the abdomen, they have to start battling all of these medical complications."
Clegg's hope is that her studies will lead to the development of "designer estrogen therapies" that would target these brain regions and reduce a menopausal woman's tendency to gain weight.
Clegg reported the findings at the 234th national meeting of the American Chemical Society.