Is your stress changing my brain?
Stress isn't just contagious; it alters the brain on a cellular level
March 8, 2018
Science Daily/University of Calgary
Scientists have discovered that stress transmitted from others can change the brain in the same way as a real stress does.
In a new study in Nature Neuroscience, Jaideep Bains, PhD, and his team at the Cumming School of Medicine's Hotchkiss Brain Institute (HBI), at the University of Calgary have discovered that stress transmitted from others can change the brain in the same way as a real stress does. The study, in mice, also shows that the effects of stress on the brain are reversed in female mice following a social interaction. This was not true for male mice.
"Brain changes associated with stress underpin many mental illnesses including PTSD, anxiety disorders and depression," says Bains, professor in the Department of Physiology and Pharmacology and member of the HBI. "Recent studies indicate that stress and emotions can be 'contagious'. Whether this has lasting consequences for the brain is not known."
The Bains research team studied the effects of stress in pairs of male or female mice. They removed one mouse from each pair and exposed it to a mild stress before returning it to its partner. They then examined the responses of a specific population of cells, specifically CRH neurons which control the brain's response to stress, in each mouse, which revealed that networks in the brains of both the stressed mouse and naïve partner were altered in the same way.
The study's lead author, Toni-Lee Sterley, a postdoctoral associate in Bains' lab said, "What was remarkable was that CRH neurons from the partners, who were not themselves exposed to an actual stress, showed changes that were identical to those we measured in the stressed mice."
Next, the team used optogenetic approaches to engineer these neurons so that they could either turn them on or off with light. When the team silenced these neurons during stress, they prevented changes in the brain that would normally take place after stress. When they silenced the neurons in the partner during its interaction with a stressed individual, the stress did not transfer to the partner. Remarkably, when they activated these neurons using light in one mouse, even in the absence of stress, the brain of the mouse receiving light and that of the partner were changed just as they would be after a real stress.
The team discovered that the activation of these CRH neurons causes the release of a chemical signal, an 'alarm pheromone', from the mouse that alerts the partner. The partner who detects the signal can in turn alert additional members of the group. This propagation of stress signals reveals a key mechanism for transmission of information that may be critical in the formation of social networks in various species.
Another advantage of social networks is their ability to buffer the effects of adverse events. The Bains team also found evidence for buffering of stress, but this was selective. They noticed that in females the residual effects of stress on CRH neurons were cut almost in half following time with unstressed partners. The same was not true for males.
Bains suggests that these findings may also be present in humans. "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."
This research from the Bains lab indicates that stress and social interactions are intricately linked. The consequences of these interactions can be long-lasting and may influence behaviours at a later time.
https://www.sciencedaily.com/releases/2018/03/180308143212.htm
How people cope with difficult life events fuels development of wisdom
February 20, 2018
Science Daily/Oregon State University
How a person responds to a difficult life event such as a death or divorce helps shape the development of their wisdom over time, a new study suggests.
For many, the difficult life event also served to disrupt their sense of personal meaning, raising questions about their understanding of their world. These disruptions ultimately lead to the development of new wisdom, said Carolyn Aldwin, director of the Center for Healthy Aging Research in the College of Public Health and Human Sciences at OSU. "The adage used to be 'with age comes wisdom,' but that's not really true," said Aldwin, an expert on psychosocial factors that influence aging. "Generally, the people who had to work to sort things out after a difficult life event are the ones who arrived at new meaning."
The findings were just published in the Journals of Gerontology: Series B. The paper's lead author is Heidi Igarashi, who worked on the research as part of the dissertation for her doctorate at OSU; co-author is Michael R. Levenson of OSU.
The goal of the study was to better understand how wisdom develops in the context of adversity such as death of a loved one, divorce, health crisis, or loss of job. Understanding how people cope with adversity and develop wisdom provides insight into healthy aging, Aldwin said. "What we're really looking at is 'when bad things happen, what happens?'" Aldwin said. "The event can become a catalyst for changes that come afterward."
Igarashi reviewed interviews with 50 adults ages 56 to 91 who had experienced one or more significant difficult life events. The participants were asked to identify a specific difficult or challenging life event, describe how they coped, and describe whether the experience changed their outlook or actions in life.
"One thing that stood out right away is that, when asked to think about a difficult life event or challenge, people had an answer right away," Aldwin said. "Difficult times are a way people define themselves." The researchers found that people responded to the difficult life situations in three ways. For one group of respondents, 13 in all, the difficult life event led to little or no questioning of meaning in their life. Part of the people in this group simply accepted the event as something that could not be changed, while the remainder described using their intelligence, self-control and planning to solve problems related to the event.
The smallest group, five participants, indicated that the difficult life event helped them clarify a specific value or belief that had not previously been articulated.
The majority of the participants -- 32 -- indicated that the difficult life event disrupted their personal meaning and prompted the person to reflect on themselves, their fundamental beliefs and their understanding of the world.
"For these folks, the event really rocked their boat and challenged how they saw life and themselves," Aldwin said.
Further analysis showed that a person's social environment helped to shape their responses to the difficult life event. These social interactions included: enlisting help from others during the difficult time; unsolicited emotional support from family, friends or strangers; being held or holding, particularly among people sharing a difficult life event such as a loss; receiving unwanted support; comparing one's reaction to the event with the reactions of others; seeking expert advice; seeking out others with similar experiences; making new connections; and learning from society at large.
The researchers found that some of these social supports and interactions influenced a person's development of wisdom. Those who received unsolicited emotional support, for example, developed wisdom around compassion and humility. Seeking others with similar experiences exposed some participants to new ideas and interactions, supporting deeper exploration of their new sense of self.
"It mattered whether a participant was expected to adjust to the event quickly and 'get back to life,' or whether they were encouraged to grow and change as a result of the event," Igarashi said. "The quality of the social interactions really make a difference."
The findings provide new insight into the role of social support and interaction in developing wisdom, she said. The challenge for now is to determine how best to ensure that people are accessing the social supports they need to cope and grow from significant life challenges.
"Typically, the type of social support you get is the kind you ask for and allow, and there is no 'one size fits all' approach," Igarashi said. "But being open to the resources in your social network, or seeking out things like grief support groups may be worth exploring."
https://www.sciencedaily.com/releases/2018/02/180220170348.htm