Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Estrogen promotes gender differences in brain’s response to stress

04.12.2003


Many stress-related mental illnesses, including depression and post-traumatic stress disorder (PTSD), occur at least twice as often in women as in men. While social and cultural factors certainly may contribute to this statistic, potential neurobiological reasons for this discrepancy have been inadequately investigated. Depression and PTSD are characterized by dysfunction of an area of the brain called the prefrontal cortex (PFC), which is known to govern higher cognitive abilities like concentration and short-term memory. These functions have been shown in lab animals to be disrupted after exposure to stress. However, the experiments have largely been done only in male animals, and sex differences in how the PFC responds to stress are unknown. A better understanding of such processes may help to elucidate the reason that women are more susceptible to stress-related disorders, and lead to the development of better anti-depressant treatments.

To examine the effects of stress on PFC function, male and female rats were exposed to different levels of mild stress, and then tested on a short-term memory task. The authors found that without stress, males and females performed equally well on the task. Likewise, after exposure to higher levels of stress, both males and females made significant memory errors. However, after exposure to a moderate level of stress, females were impaired, but males were not, suggesting that females were more sensitive to the PFC-impairing effects of stress. When the authors monitored the female rats’ estrus cycles, they found that the rats showed this sensitivity only when they were in a high-estrogen phase. To further investigate the role of estrogen in this effect, Shansky et al removed the ovaries of a new group of female rats, thus eliminating any circulating estrogen. A time-release capsule containing either estrogen or placebo was implanted and the experiment repeated. Estrogen replacement had the same effect as naturally circulating estrogen--animals with estrogen capsules displayed the same sensitivity to stress that females in the high-estrogen estrus phase did, while animals with placebo capsules were unaffected.

Together, these results suggest that high levels of estrogen can act to enhance the stress response, causing greater stress-related cognitive impairments. It is important to note, however, that estrogen had no effect on cognitive performance under non-stressful conditions. The idea that estrogen could contribute to the higher prevalence of stress-related disorders in women is consistent with reports that the discrepancy first arises at puberty, maintains through the child-bearing years, and then declines, such that it is equally likely to occur in post-menopausal women as in men of the same age. The mechanisms by which estrogen may be producing these effects are to date unknown, but currently under investigation. It is known that estrogen can interact with molecular processes involved in the stress response, and that certain genetic variations have been demonstrated in clinically depressed women. However, how these factors might combine to produce the glaring disparity in the prevalence of this disorder awaits discovery. Such knowledge will hopefully lead to the development of new, more effective treatments for depression.




Citation source: Molecular Psychiatry advance online publication, December 2003 (doi:10.1038/sj.mp.4001435)

ARTICLE: "Estrogen mediates sex differences in stress-induced prefrontal cortex dysfunction"

AUTHORS: Rebecca M Shansky, Courtney Glavis-Bloom, David Lerman, Paulette McRae, Christopher Benson, Katherine Miller, Louise Cosand, Tamas L Horvath and Amy FT Arnsten

Aimee Midei | EurekAlert!
Further information:
http://www.naturesj.com/mp/

More articles from Social Sciences:

nachricht Amazingly flexible: Learning to read in your thirties profoundly transforms the brain
26.05.2017 | Max-Planck-Institut für Kognitions- und Neurowissenschaften

nachricht Fixating on faces
26.01.2017 | California Institute of Technology

All articles from Social Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>