The chemical make up of stress

By Erin Shumlich

A University of Calgary research team has reached a new step in understanding the mechanisms that control stress in the mind and body.

Jaideep Bains, associate professor in physiology at the U of C Hopkins brain institute and his team tackled this question on a cellular level. After finding that a specific mechanism was able to switch on and off a centre in the brain that controlled stress, Bains researched the physiological changes that occur which cause us to react to stress.

“We have known for a long time that the brain is the key organ that interprets stress signals and organizes all the body’s resources to respond to stress,” said Bains. “The first description of this was in the late 1930s and over the last 30 years there has been a lot of research trying to understand how mammals respond to stress.”

Bains studies just how stress neurons get turned on, off and adapt to stress. When the body responds to stress, multiple hormones released by the hypothalamus send a signal to the rest of the body initiating a string of stress-related responses.

“What I am really interested in my lab is understanding how synapses, elements that connect neurons, remember information,” said Bains. “One of the things that we hypothesized was that in order for this to happen, there must be some sort of imprinting at the level of these synapses.”

Individuals that are stressed for a long period of time are found to have difficulty recalling information. Everyone deals with stress on a day to day basis, but there are many ways to cope. The best way to prevent stress is through lifestyle or behavioral modification.

“There is an accumulation across different stressors, but I think a lot of people have amazing capacities to adapt and filter out those stresses,” Bains said. “When you are stressed, there is a memory in your stress system that you don’t want to be prolonged. When it gets prolonged, you get stress hormones being released for a long period of time that are not very helpful. One of the best ways to deal with those types of stressors is to do things like exercise.”

Bains was able to find a chemical in the lab that blocks an important stress pathway receptor, effectively creating an antidote of stress on paper. However this treatment could not be used in humans because without this pathway initial responses to stress needed to survive would be blocked. The next step for Bains is looking further down the response line to target a more specific response.

“As far as how different stressors are interpreted by humans as opposed to in the lab conditions, it’s pretty open,” said Bains. “Humans are pretty complex and everyone has different capacities to deal with stress.”

Bain’s future focus is exploring the connection between stress in adolescence and an ability to cope with stress later in life.

“Anecdotally during adolescence, you’re very sensitive to external stressors,” said Bain. “We are beginning to become very interested in long term imprinting. We would really like to start to think about critical periods were your brain is open to influences and is very plastic and how being exposed to cues during those key windows lead to long lasting changes later on.”