A recent research in rats by scientists at the Emory University School of Medicine, the Yerkes National Primate Research Center, and Atlanta’s Center for Behavioral Neuroscience revealed that a steroid hormone that is released at the time of metabolism of the female sex hormone (progesterone) has an ability to minimize response of the brain to stress.

The involved scientists found enough evidence to suggest that progesterone metabolite allopregnanolone minimizes the response of brain to CRF (corticotropin-releasing factor). It is important to note here that CRF is a peptide hormone, which tends to play a critical role in stress response in animals.

Emory researchers Donna Toufexis, PhD, Michael Davis, PhD and Carrie Davis, BS, and Alexis Hammond, BS, of Spelman College made comparisons on how female rats with varying levels of estrogen and progesterone, the sex hormones, reacted to loud noises after CRF injections into lateral ventricles of the brain.

From News-Medical.Net:

Previous studies have determined that allopregnanolone enhances the activity of GABA, the main inhibitory neurotransmitter in the central nervous system, at its receptors throughout the brain. This mechanism, Toufexis said, likely accounts for progesterone’s blunting effect on the brain’s stress system.

Findings from the study correlate with clinical evidence that some people suffering from depression or anxiety have low allopregnanolone levels that normalize after treatment with anti-depressant medications.

“New drugs could potentially be developed that mimic the effect of allopregnanolone on the GABA receptor, providing a new approach for controlling mood disorders in women,” said Toufexis. “The next step is to determine where exactly allopregnanolone is working in the brain to reduce the effect of CRF.”

The finding of this study is believed to offer a new drug target for the treatment of depression and anxiety in women.