Navigation Links
New brain nerve cells key to stress resilience, UT Southwestern researchers find
Date:3/30/2010

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
lakisha.ladson@utsouthwestern.edu
214-648-3404
UT Southwestern Medical Center
Source:Eurekalert

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:
*Name:
*Comment:
*Email:
(Date:6/2/2016)... -- Perimeter Surveillance & Detection Systems, Biometrics ... Support & Other Service  The latest report ... analysis of the global Border Security market . ... $17.98 billion in 2016. Now: In November ... software and hardware technologies for advanced video surveillance. ...
(Date:5/20/2016)... -- VoiceIt is excited to announce its new marketing ... working together, VoiceIt and VoicePass will offer an ... slightly different approaches to voice biometrics, collaboration between ... Both companies ... "This marketing and technology partnership allows VoiceIt ...
(Date:5/9/2016)... -- Elevay is currently known as the ... high net worth professionals seeking travel for work   ... there is still no substitute for a face-to-face meeting. ... deal with a firm handshake. This is why wealthy ... citizenship via investment programs like those offered by the ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... 27, 2016 , ... Parallel 6 , the leading software as a ... Reach Virtual Patient Encounter CONSULT module which enables both audio and video telemedicine ... team. , Using the CONSULT module, patients and physicians can schedule a face to ...
(Date:6/27/2016)... ... June 27, 2016 , ... Rolf K. Hoffmann, ... faculty of the University of North Carolina Kenan-Flagler Business School effective ... at UNC Kenan-Flagler, with a focus on the school’s international efforts, leading classes ...
(Date:6/27/2016)... Ginkgo Bioworks , a leading organism design company ... as one of the World Economic Forum,s Technology ... companies. Ginkgo Bioworks is engineering biology to manufacture ... the nutrition, health and consumer goods sectors. The ... Fortune 500 companies to design microbes for their ...
(Date:6/24/2016)... 24, 2016 Epic Sciences unveiled a ... susceptible to PARP inhibitors by targeting homologous recombination ... The new test has already been incorporated into ... cancer types. Over 230 clinical trials ... pathways, including PARP, ATM, ATR, DNA-PK and WEE-1. ...
Breaking Biology Technology: