Navigation Links
Vulnerability to Stress Linked to Brain Molecule
Date:10/18/2007

Study with mice reveals heightened activity of neurotransmitter dopamine

THURSDAY, Oct. 18 (HealthDay News) -- Researchers have identified molecular mechanisms in the brain that may explain why some people are less vulnerable to the stress caused by difficult situations.

While the research was done with mice, the findings could eventually lead to better treatments for chronic stress, depression and the post-traumatic stress disorder suffered by troops in Iraq and other battlefields, said study co-author Dr. Eric Nestler, chairman of psychiatry at the University of Texas Southwestern Medical Center at Dallas.

"One important lesson we have shown even in previous papers is that a series of genetically identical animals respond differently to chronic stress," Nestler said. "Thirty to 40 percent seemed to be resilient and did not develop bad symptoms. The clinical implications are that the ability to identify mechanisms of resistance can help provide new and novel approaches to stress."

The key lies in a pair of molecules used by some brain cells to communicate with one another, said Vaishnav Krishnan, lead author of the report and a student in a University of Texas Southwestern Medical Center program that leads to simultaneous M.D. and Ph.D. degrees.

"Under stress, vulnerable mice increase the frequency of nerve activity using the neurotransmitter dopamine," Krishnan said. "That subsequently causes release of a nerve growth factor called brain-derived neurotrophic factor [BDNF]. Resilient mice overcome these changes by increasing the expression of molecules that prevent the release of dopamine."

A neurotransmitter is a molecule that sends signals from one nerve cell to another.

Mice in the experiments were so inbred that they were genetically identical. Then they were put under stress by being placed in the territory of larger, more aggressive mice. Some of the test mice adjusted well to the stress of the situation, while others avoided contact and showed submissive behavior.

The researchers then made detailed studies of two brain regions -- the ventral tegmental area (VTA) and the nucleus accumbens (NAcc), which are part of the brain's reward area that promotes acts that aid in survival. They found that the excess BNDF production in vulnerable mice occurred in the VTA but not the NAcc region. Chemical signals sent by the protein from the VTA to the NAcc made the mice vulnerable to stress. Experimental compounds that blocked those signals turned vulnerable mice into resistant mice.

The findings, published online Oct. 18 in the journal Cell, raise the possibility of "tools to develop things in the brain that encourage resilience, to help people with stress," Nestler said.

"We have always tried to understand the changes in the brain that lead to such things as the symptoms of post-traumatic stress disorder," Krishnan added. "This study shows we can increase our understanding and development of new therapeutic measures to overcome those changes."

But new therapies might not be easy to develop, Nestler said, since a decrease of dopamine or BDNF activity might be helpful in one part of the brain but harmful in another area.

Dr. Thomas R. Insel, director of the U.S. National Institute of Mental Health, which funded the research, said the findings are "part of a large body of work coming out of Dr. Nestler's laboratory trying to understand what this important neurotrophic molecule, BDNF, does."

"What's exciting here is that it is important for resilience, being able to recover from a traumatic event," Insel added. "One of the great values of this work is to help us understand how mammals, including humans, might be able to recover from the traumas inherent in human existence."

More information

Learn more about the role of stress in sickness and health from the American Institute of Stress.



SOURCES: Eric Nestler, M.D., chairman, department of psychiatry, and Vaishnav Krishnan, student, University of Texas Southwestern Medical Center at Dallas; Thomas R. Insel, M.D., director, U.S. National Institute of Mental Health, Bethesda, Md.; Oct. 18, 2007, Cell, online


'/>"/>
Copyright©2007 ScoutNews,LLC.
All rights reserved

Related medicine news :

1. Gene variants hold clues about vulnerability to cardiovascular disease
2. Adolescent Smokers Have Greater Vulnerability To AUDs Than Do Non-Smokers
3. Vulnerability to Ear Infections Lessened by Breast Feeding
4. Weed Killer Plays a Pivotal Role in Those With Genetic Vulnerability to Parkinson’
5. Stress reduces your immunity- startling but true!!!!!
6. Meditation relieves stress
7. New guidelines for dealing with post traumatic stress disorder
8. Meditation relieves stress
9. Stress can make you overweight
10. Stress response increases suicide risk
11. Avoid stress to have strong babies
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/7/2016)... ... February 07, 2016 , ... Women's Excellence staff, in all four locations, ... National Wear Red Day is the first Friday each February and a day to ... 1 in 3 deaths among women each year – more than all cancers combined. ...
(Date:2/6/2016)... ... February 06, 2016 , ... US Sports Camps is proud to sponsor ... event brings together top non-profit leaders, ultimate organizations, and coaches from around the US. ... Bay Area Disc Program Director of Youth and Education, describes this year YUCC as ...
(Date:2/5/2016)... ... February 05, 2016 , ... Steven Tonkinson, 36, of Coconut Grove, ... year since it started in 2003. This year, he ran all 26.2 miles with ... and NBA team the Miami Heat. , This Sunday, while many are watching the ...
(Date:2/5/2016)... ... February 05, 2016 , ... ... stage for new clinical and scientific initiatives have all marked the last 12 ... appointed President and CEO of the nation’s oldest cancer center, Candace S. Johnson, ...
(Date:2/5/2016)... York, New York (PRWEB) , ... February 05, 2016 , ... ... life? The answer may be at the tips of your toes. Foot massage, whether ... as well as pure comfort and relaxation. The American Board of Multiple Specialties ...
Breaking Medicine News(10 mins):
(Date:2/5/2016)... 2016  Patients in Alabama seeking ... therapy no longer have to travel out of state. ... Urology Centers of Alabama to provide a total ... qualifying patients. Alabama is ... of prostate cancer using many different modalities. They are the ...
(Date:2/5/2016)... 5, 2016 --> ... states that the global active pharmaceuticals ingredients (APIs) market ... to reach US$185.9 bn by 2020. It is expected ... to 2020. The title of the report is "Active ... Geography, and by Therapeutic Area) - Global Industry Analysis, ...
(Date:2/5/2016)... Site Profile: --> Site ... People, announced their latest primary healthcare case study where speech recognition ... and to save the practice money. Site Profile: ... Challenge: --> ,- Wirral CCG ,- VoicePower client since ... Wirral CCG ,- VoicePower client since 2013 Challenge: ...
Breaking Medicine Technology: