Estrogen gives females an advantage with stress

Photo Credit Greenfieldboyce, 2011

Females are superior to males; a fact that women have been scouring to prove for decades, even if for their own satisfaction or to just rub in it the faces of men. But, there may be certain key benefits for those of us with the ability to produce estrogen. A recent study from the University of Buffalo has been working to determine the protective effects of estrogen in the brains of female rats in response to stress. Overall females tend to show a better response or less of an adverse effect to stress and the underlying factor may be estrogen. You may say, “males have the ability to produce estrogen as well”, and although that statement is true the amounts of which are produced in both are drastically different. But, if males could produce or be given a safe way to produce or maintain estrogen in their brains they may have the same reaction to stress.

The original article "Estrogen protects against the detrimental effects of repeated stress on glutamatergic transmission and cognition" outlines the entire procedure done on the rats for this experiment. The researchers used several different methods of recording data from the rats being examined; the first was simple behavior testing. The rats were subject to temporal order recognition memory (TORM) tasks, which consisted of two sample phases and one test phase (Wei & Yuen, 2013). During the sample phases two plastic objects, of the same height and material, were shown to the rats and the rats were allowed to check out (Wei & Yuen, 2013). In each phase there were two different objects, but in the final test phase one object from the first phase and another from the second phase were used to test the rats short-term memory (Wei & Yuen, 2013). If everything is in working order within the rats brain, the rats will spend more time checking out the object from phase one because it has been the longest since it has seen it (Wei & Yuen, 2013). Another test used was actual slices of the experimental rats’ brains to examine closer into the physiological effects of stress.

The stressors of the experiment were preformed two-hours daily for five to seven days with the last happening about a day before test were going to be done on the individual rat (Wei & Yuen, 2013). The rats were placed in cylinder containers that were just barely big enough to contain the rat with minimal room to maneuver around within it (Wei & Yuen, 2013). This stimulated a stressful response in the rats given the confines of the space they were limited to compared to the space they were used to. After the stressed rats came out of the last round in the small containers a day was used as s rest period before the TORM tests began.

Female rats showed much better responses in all categories studies compared to male mice so the researchers wanted to look into the effects of estrogen specifically. The repeated stressors imposed on females showed to be the same as males when their estrogen signaling was blocked and the male rats exhibited behavior similar to females when their estrogen signaling was activated (Wei & Yuen, 2013). This experimentation shows a linkage between estrogen and the effects of stress.

The biology behind the estrogen receptors in the brain is focused on the glutamate receptors in the prefrontal cortexregion of the brain which is the outermost layer of brain matter directly behind the forehead, or frontal bone (Prefrontal cortex, 2013). This area is very important in complex cognitive processes such as memory and emotion (Prefrontal Cortex, 2013). Glutamate receptors are located in the prefrontal cortex and the neurotransmitter glutamate is essential to the central nervous system because of their properties as an excitatory transmitter (Danbolt, 2001). The normal functioning of glutamate neurotransmitters is important to human memory, cognition, and learning which are all very important to human activities (Danbolt, 2001).

In the study discussed researchers found that glutamate receptors in the prefrontal cortex of female rat brain slices examined were completely intact, but not intact in males (University at Buffalo, 2013). This gives researchers clues that the glutamate receptors are targets of stress causing a loss of function in that area which houses memory and cognition (University at Buffalo, 2013). In females the stressors aren’t as debilitating cognitively as is shown in males; therefore there is a protective factor at work here. The common thread is estrogen; scientists should now be working on a way to get the protective effects of estrogen into males without having harmful side effects. With that technology both males and females will be on an even playing field in terms of stress.  

Danbolt, N. (2001). Glutamate as a neurotransmitter-an overview . Retrieved from http://neurotransporter.org/glutamate.html

Greenfieldboyce, N. (2011, December 08). Cagebreak! rats will work to free a trapped pal. Retrieved from http://www.npr.org/2011/12/09/143304206/cagebreak-rats-will-work-to-free-a-trapped-pal

Prefrontal cortex. 2013. In Merriam-Webster.com. Retrieved November 4, 2013, from http://www.merriam-webster.com/dictionary/prefrontal%20cortex

University at Buffalo, (2013, July 11). Females respond better to stress becasue of estrogen in the brain, animal study finds.. Retrieved from http://www.sciencedaily.com/releases/2013/07/130710061824.htm

Wei, J., & Yuen, E. (2013). Estrogen protects against the detrimental effects of repeated stress on glutanatergic transmission and cognition. Molecular Psychiatry, 1-11. doi: 10.1038 Retrieved from http://www.nature.com/mp/journal/vaop/ncurrent/full/mp201383a.html