Previous research found that stress and emotions can be “contagious,” in that if a person nearby is upset or stressed, you may become upset or stressed as well. Now, recent research says this stress transmitted from others may alter the brain just as real stress does. This study “Social transmission and buffering of synaptic changes after stress” also found that the harmful effects of stress on the female brain may be reversed by social interactions—but this doesn’t ring true for males.
To reach these findings, the researchers studied pairs of male mice and pairs of female mice and the effects stress had on them. They separated the pairs, exposed one of the mice to a mild stressor, and then reunited them. Then, the researchers analyzed how a specific area of cells—CH neurons, which control the brain’s stress response—responded in each mouse. They found that the brain networks were altered in the same way: in the mice exposed to stress and their partners. Toni-Lee Sterley, the study’s lead author and a postdoctoral associate in Bains’ lab, described this observation as “remarkable.”
Continuing on with their experimentation, the group of researchers then engineered the mice’s neurons to turn on or off with light. When they turned the neurons off during times of stress, they were able to stop changes in the brain that would typically occur with stress. And when they turned the neurons off in the partners’ brains during interactions with their stressed mate, they came out stress-free. Furthermore, when the team turned these neurons on in one mouse—even without the normal stress induction—that mouse’s brain and his or her partner’s brain were altered as they would be following stress.
Upon doing so, the researchers found that activation of those CRH neurons causes an “alarm pheromone” to be released, which alerts the partner who is not directly experiencing stress. The partner can then alert other individuals, which is important to the formation and maintenance of social networks. Additionally, social networks have the power to lessen the harmful effects of stress on an individual, as observed by the researchers. They found in the female mice that the effects of stress on CRH neurons were cut in half after they spent time with unstressed partners.
Bains, professor in the Department of Physiology and Pharmacology and member of the HBI, believes that these findings likely transfer over into humans, as there is observable evidence: “We readily communicate our stress to others, sometimes without even knowing it. There is even evidence that some symptoms of stress can persist in family and loved ones of individuals who suffer from PTSD. On the flip side, the ability to sense another’s emotional state is a key part of creating and building social bonds.”
University of Calgary (2018, March 8). Is Your Stress Changing My Brain?. NeuroscienceNews. Retrieved March 8, 2018 from http://neurosciencenews.com/stress-brain-change-8611/
Sterley, T., Baimoukhametova, D., Fuzesi, T., Zurek, A. A., Daviu, N., Rasiah, N. P., Rosenegger, D., & Bains, J. S. (2018, January 8). Social transmission and buffering of synaptic changes after stress. Nature Neuroscience. Retrieved on March 13, 2018 from https://www.nature.com/articles/s41593-017-0044-6