Researchers have long wondered why some people are resilient to stress while others aren't. A new mouse study may have brought them a step closer to the answer.
Dr. Eric J. Nestler of the University of Texas Southwestern Medical Center led a research team investigating the vulnerability of mice to stress after social defeat. When mice are put in cages with bigger, more aggressive mice, some still avoid social interactions with other mice even a month later—a sign that the stress has overwhelmed them. Some, however, adapt and continue to interact with others. The differences between these groups gave Nestler and his team the opportunity to examine the biology behind stress resilience. Their research was funded by NIH's National Institute of Mental Health (NIMH).
The researchers found that the mice that do not recover from stress have higher rates of nerve cell electrical activity in the cells that make dopamine. Dopamine is a chemical that helps transmit nerve impulses. More nerve cell electrical activity caused the subject mice to make more of a protein (BDNF), which has been linked to weakness to stress.
"The fact that we could increase these animals' ability to adapt to stress by blocking BDNF and its signals means that it may be possible to develop compounds that improve our own resilience to stress. This is a great opportunity to explore how to increase resistance in situations that might otherwise result in post-traumatic stress disorder, for example," said Dr. Nestler.