Navigation Links
New brain nerve cells key to stress resilience, UT Southwestern researchers find

DALLAS March 31, 2010 UT Southwestern Medical Center researchers have found new clues that might help explain why some people are more susceptible to stress than others.

In a study of mice, the researchers determined that weeks after experiencing a stressful event, animals that were more susceptible to stress exhibited enhanced neurogenesis the birth of new nerve cells in the brain. Specifically, the cells that these animals produced after a stressful event survived longer than new brain cells produced by mice that were more resilient.

In addition, when researchers prevented neurogenesis in both stress-susceptible and resilient mice, the animals previously susceptible to stress became more resilient.

"This work shows that there is a period of time during which it may be possible to alter memories relevant to a social situation by manipulating adult-generated nerve cells in the brain," said Dr. Amelia Eisch, associate professor of psychiatry at UT Southwestern and senior author of the study, available in the Proceedings of the National Academy of Sciences. "This could eventually lead to a better understanding of why, in humans, there is an enormous variety of responses to stressful situations."

Mice that are susceptible to stress exhibit long-lasting social avoidance and depressive-like behavior after experiencing a stressful event, such as being placed in a cage with a more aggressive mouse. Resilient mice behave more like unstressed control animals. This animal model is commonly used in studies of stress and depression, as understanding the changes in the brain and behavior of the mice can shed light on stress-induced changes in the human brain and in human behavior.

In the study, the brain cells of both groups of mice responded in similar ways after a stressful event. But weeks later, researchers found that mice displaying social avoidance had more nerve cells in a region of the brain called the hippocampus that survived the stressful event than mice that were more resilient.

The study is the first to link the memory of a social experience with neurogenesis in the hippocampus, Dr. Eisch said. Recently, Dr. Eisch and her team have linked adult neurogenesis with addiction. Previously, neurogenesis was primarily associated with spatial learning and memory.

In this study, Dr. Eisch and her colleagues exposed some mice to social defeat by having the animals live in the same cage as larger, aggressor mice for five minutes a day, and in the same cage but with a barrier in place the rest of the day. Researchers then tested the mice to see if they were susceptible to stress.

The researchers labeled the new cells of susceptible and unsusceptible mice so they could see how the cells divided. Both types of mice produced fewer dividing cells immediately after stress, but in the long run, mice susceptible to stress had more new adult cells than unsusceptible and control mice, who lived in cages with nonaggressor mice.

Dr. Eisch and her colleagues also used radiation to prevent hippocampal neurogenesis in all groups of mice. Mice susceptible to stress stopped producing new nerve cells and didn't display social avoidance in the long term.

Inhibiting social avoidance also had detrimental effects, however.

"Radiation in susceptible mice led to behavior that might be interpreted as harmful, such as approaching a potential aggressor mouse instead of avoiding it. We hypothesize that the survival of new nerve cells may be a compensatory event in the brain to allow the mouse to remember a socially relevant aggressor," Dr. Eisch said. "We are very eager to see if these results carry over to other models of stress in animals and to explore the mechanisms underlying these changes, as these are critical steps to understanding how adult-generated neurons might be modulated to help humans in stressful situations."

Future studies also will help determine which genes are involved with increased survival of new nerve cells in mice susceptible to stress, Dr. Eisch said.


Contact: LaKisha Ladson
UT Southwestern Medical Center

Related biology news :

1. Invasion of the brain tumors
2. HIV is a double hit to the brain
3. AIDS interferes with stem cells in the brain
4. 60 second test could help early diagnosis of common brain diseases
5. U of MN researchers discover noninvasive diagnostic tool for brain diseases
6. U of Minnesota researchers discover noninvasive diagnostic tool for brain diseases
7. Influence of sex and handedness on brain is similar in capuchin monkeys and humans
8. Inside the brain of a crayfish
9. Specific brain protein required for nerve cell connections to form and function
10. Brains timing linked with timescales of the natural visual world
11. Adult brain can change, study confirms
Post Your Comments:
(Date:10/29/2015)... 29, 2015  The J. Craig Venter Institute (JCVI) ... Synthesis and Biosecurity: Lessons Learned and Options for the ... and Human Services guidance for synthetic biology providers has ... --> --> Synthetic biology ... potential to pose unique biosecurity threats. It now is ...
(Date:10/29/2015)... , October 29, 2015 ... authentication company focused on the growing mobile commerce ... announces that StackCommerce, a leading marketplace to discover ... the Wocket® smart wallet on StackSocial for this ... ("NXT-ID" or the "Company"), a biometric authentication company ...
(Date:10/27/2015)... 27, 2015 Synaptics Inc. (NASDAQ: SYNA ), ... Google has adopted the Synaptics ® ClearPad ® ... power its newest flagship smartphones, the Nexus 5X by ... --> --> Synaptics works ... strategic collaboration in the joint development of next generation ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... ... November 25, 2015 , ... ... Organization of Black Aerospace Professionals (OPBAP) has been formalized with the signing of ... team leaders met with OPBAP leaders Capt. Karl Minter and Capt. Albert Glenn ...
(Date:11/25/2015)... Francisco, CA (PRWEB) , ... November 25, 2015 ... ... microbial genomics company uBiome, were featured on AngelList early in their initial angel ... launching an AngelList syndicate for individuals looking to make early stage investments in ...
(Date:11/24/2015)... 24, 2015 Cepheid (NASDAQ: CPHD ) ... the following conference, and invited investors to participate via ...      Tuesday, December 1, 2015 at 11.00 a.m. Eastern ...      Tuesday, December 1, 2015 at 11.00 a.m. Eastern ... New York, NY      Tuesday, December 1, ...
(Date:11/24/2015)... Mass. (PRWEB) , ... November 24, 2015 , ... ... to maintain healthy metabolism. But unless it is bound to proteins, copper is ... of Health (NIH), researchers at Worcester Polytechnic Institute (WPI) will conduct a systematic ...
Breaking Biology Technology: