Higher anxiety, depression among women may have basis in cell signals

June 15, 2010

There may be a biological reason why depression and other stress-related psychiatric disorders are more common among women compared to men. Studying stress signaling systems in animal brains, neuroscience researchers found that females are more sensitive to low levels of an important stress hormone and less able to adapt to high levels than males.

"This is the first evidence for sex differences in how neurotransmitter receptors traffic signals," said study leader Rita J. Valentino, Ph.D., a behavioral neuroscientist at The Children's Hospital of Philadelphia. "Although more research is certainly necessary to determine whether this translates to humans, this may help to explain why women are twice as vulnerable as men to stress-related disorders."

The research appears online today in . The study's first author is Debra A. Bangasser, Ph.D., a fellow in Valentino's laboratory.

It has long been recognized that women have a higher incidence of depression, post-traumatic stress disorder, and other , said Valentino, but underlying biological mechanisms for that difference have been unknown. Her research focuses on corticotropin-releasing factor (CRF), a hormone that organizes stress responses in mammals.

Analyzing the brains of that responded to a swim stress test, Valentino's team found that in female rats, neurons had receptors for CRF that bound more tightly to cell signaling proteins than in male rats, and thus were more responsive to CRF. Furthermore, after exposure to stress, male rats had an adaptive response, called internalization, in their . Their cells reduced the number of CRF receptors, and became less responsive to the hormone. In female rats this adaptation did not occur because a protein important for this internalization did not bind to the CRF receptor.

"This is an animal study, and we cannot say that the is the same in people," said Valentino, adding that other mechanisms play a role in human stress responses, including the actions of other hormones. However, she added, "researchers already know that CRF regulation is disrupted in stress-related psychiatric disorders, so this research may be relevant to the underlying human biology."

Furthermore, said Valentino, much of the previous research on disorders in animal models used only male rodents, so important sex differences may have gone undetected. "Pharmacology researchers investigating CRF antagonists as drug treatments for depression may need to take into account gender differences at the molecular level," she said.

More information: "Sex differences in corticotrophin-releasing factor receptor signaling and trafficking: potential role in female vulnerability to stress-related psychopathology," Molecular Biology, published online June 15, 2010. dx.doi.org/10.1038/MP.2010.66

Related Stories

Recommended for you

Probing how Americans think about mental life

October 20, 2017
When Stanford researchers asked people to think about the sensations and emotions of inanimate or non-human entities, they got a glimpse into how those people think about mental life.

Itsy bitsy spider: Fear of spiders and snakes is deeply embedded in us

October 19, 2017
Snakes and spiders evoke fear and disgust in many people, even in developed countries where hardly anybody comes into contact with them. Until now, there has been debate about whether this aversion is innate or learnt. Scientists ...

Dutch courage—Alcohol improves foreign language skills

October 18, 2017
A new study published in the Journal of Psychopharmacology, conducted by researchers from the University of Liverpool, Maastricht University and King's College London, shows that bilingual speakers' ability to speak a second ...

Inflamed support cells appear to contribute to some kinds of autism

October 18, 2017
Modeling the interplay between neurons and astrocytes derived from children with Autism Spectrum Disorder (ASD), researchers at University of California San Diego School of Medicine, with colleagues in Brazil, say innate ...

Study suggests psychedelic drugs could reduce criminal behavior

October 18, 2017
Classic psychedelics such as psilocybin (often called magic mushrooms), LSD and mescaline (found in peyote) are associated with a decreased likelihood of antisocial criminal behavior, according to new research from investigators ...

Taking probiotics may reduce postnatal depression

October 18, 2017
Researchers from the University of Auckland and Otago have found evidence that a probiotic given in pregnancy can help prevent or treat symptoms of postnatal depression and anxiety.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

akotlar
not rated yet Jun 15, 2010
Clearly female rats, and female humans have very similar brains. Well done.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.