Scientists find molecular evidence of brain changes in depressed females

September 16, 2011, University of Pittsburgh

Researchers at the University of Pittsburgh School of Medicine have discovered molecular-level changes in the brains of women with major depressive disorder that link two hypotheses of the biological mechanisms that lead to the illness. Their results, published online this week in Molecular Psychiatry, also allowed them to recreate the changes in a mouse model that could enhance future research on depression.

Although women are twice as likely as men to develop depression and have more severe and frequent symptoms, very little research has focused on them or been conducted in other female animals, noted senior author Etienne Sibille, Ph.D., associate professor of psychiatry, Pitt School of Medicine.

"It seemed to us that if there were in the depressed brain, we might be able to better identify them in samples that come from females," he said. "Indeed, our findings give us a better understanding of the biology of this common and often debilitating psychiatric illness."

The researchers examined post-mortem samples of 21 women with depression and 21 similar women without a history of depression. Compared to their counterparts, the depressed women had a pattern of reduced expression of certain genes, including the one for brain-derived neurotrophic factor (BDNF), and of genes that are typically present in particular subtypes of , or neurons, that express the neurotransmitter gamma-aminobutyric acid (GABA.) These findings were observed in the amygdala, which is a brain region that is involved in sensing and expressing emotion.

In the next part of the project, the researchers tested mice engineered to carry different mutations in the BDNF gene to see its impact on the GABA cells. They found two mutations that led to the same deficit in the GABA subtype and that also mirrored other changes seen in the human depressed brain.

Dr. Sibille noted that researchers have long suspected that low levels of BDNF play a role in the development of depression, and that there also is a hypothesis that reduced GABA function is a key factor.

"Our work ties these two concepts together because we first show that BDNF is indeed low in depression and second that low BDNF can influence specific GABA cells in a way that reproduces the biological profile we have observed in the depressed brain," he said.

The team is continuing to explore the molecular pathway between BDNF and GABA and others that could be important in depression.

Explore further: Ketamine helps see how the brain works in clinical depression

Related Stories

Ketamine helps see how the brain works in clinical depression

June 16, 2011
(Medical Xpress) -- In a new study published in Nature, Lisa Monteggia from the University of Texas Southwestern Medical Center looks at how the drug ketamine, typically used as an anesthetic or a popular recreational drug ...

Recommended for you

People can handle the truth (more than you think)

September 19, 2018
Most people value the moral principle of honesty. At the same time, they frequently avoid being honest with people in their everyday lives. Who hasn't told a fib or half-truth to get through an awkward social situation or ...

Mindfulness meditation: 10 minutes a day improves cognitive function

September 19, 2018
Practising mindfulness meditation for 10 minutes a day improves concentration and the ability to keep information active in one's mind, a function known as "working memory". The brain achieves this by becoming more efficient, ...

Study reveals cannabinoid drugs make pain feel 'less unpleasant, more tolerable'

September 19, 2018
Researchers in the College of Arts and Sciences have determined that cannabinoid drugs do not appear to reduce the intensity of experimental pain, but, instead, may make pain feel less unpleasant and more tolerable.

Close intercultural romantic relationships and friendships can boost creativity

September 19, 2018
You've worked abroad. You've lived abroad. But have you had a close friendship or romantic relationship with a person from a culture drastically different from your own?

The 'real you' is a myth – we constantly create false memories to achieve the identity we want

September 19, 2018
We all want other people to "get us" and appreciate us for who we really are. In striving to achieve such relationships, we typically assume that there is a "real me". But how do we actually know who we are? It may seem simple ...

New research helps to instill persistence in children

September 19, 2018
Encouraging children "to help," rather than asking them to "be helpers," can instill persistence as they work to fulfill daily tasks that are difficult to complete, finds a new psychology study.

0 comments

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.