Unravelling the mystery of stress

Plastering the pages of magazines and self-help books, stress is a hot topic for overworked North Americans – it's also a poorly understood concept, says neuroscientist Dr. Gerlinde Metz.

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"It's a very timely subject these days; people think about it a lot. But it's also a misused term," says Metz, a principal researcher at the University of Lethbridge's Canadian Centre for Behavioural Neuroscience (CCBN).

Stress isn't solely an emotional condition; it's also a physiological state related to the flight-or-fight response that can be both helpful and damaging. The release of stress hormones, like adrenaline, can help an organism flee a harmful situation, but unmanaged long-term stress can increase the likelihood of certain health conditions and diseases.

"It's very complex. Stress affects so many different organs, so many different functions and the brain in so many different ways," she explains.

In the context of brain injury, stress is relevant on two dimensions. "On one hand, stress is a predisposing factor," says Metz. "On the other hand, if you have a stroke, experiencing a loss of movement and cognitive functions is also a source of stress."

Metz is systematically studying the impact of stress on normal motor system functions – including the complex interactions of hormones and their effects on the motor system – as well as how stress impacts the recovery of brain injury patients, particularly victims of 'silent' stroke, in which a stroke isn't immediately detected (these account for 70 per cent of all strokes).

Traditional rehabilitation therapy for stroke patients takes a tremendous physical toll on them. Inte

nse training, amounting to hours of exercise each day, is needed to enable patients to regain movement.

The result is an accumulation of stress – not only from the loss of normal motor control and the adjustment to a major health condition, but from the treatment itself. By understanding the cellular processes at the heart of stress, and how these relate to different types of brain damage, Metz hopes to find ways to "optimize existing stroke treatments and maybe find ones that haven't been discovered yet."

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For instance, non-traditional treatments like massage therapy, known for its ability to lower stress levels, may prove to be a helpful compliment to rehabilitation.

Metz's work on stress is primarily funded by the Alberta Heritage Foundation for Medical Research (AHFMR) which recently renewed her status as an AHFMR Senior Scholar and provided funding of more than $1 million over the next seven years. Metz also receives funding from the Canadian Institutes for Health Research and the Natural Sciences and Engineering Research Council.

In addition to her work on stress and stroke, Metz is actively collaborating on a project for the Preterm Birth and Healthy Outcomes Team, a network of researchers and clinicians from across Alberta.

Working with peers from the Canadian Centre for Behavioural Neuroscience, Metz is studying an animal model of preterm birth in order to understand the physiological factors of the phenomenon, particularly hormones.

"Pregnancy is regulated by a complex concert of hormones," says Metz. "Sometimes, something goes wrong at some point. Once we know what's not working, we can try to repair it."

Metz explains that preterm birth is a complex occurrence, the causes of which have eluded scientists. It's a particularly relevant health concern in Alberta, where more than 9 per cent of babies are born prematurely – the highest rate in Canada.

The Preterm Birth and Healthy Outcomes Team includes 20 principal investigators, including Metz, who recently earned a team grant from AHFMR, an award of $5 million over five years, to explore the issue from three main perspectives: the health of mothers, the health of infants and the long-term health outlook for people born prematurely.

"The focus of the team grant is to bring many different people to the table and have them focus on a single topic," says Metz.

Health-care professionals working with mothers and preterm babies comprise an important part of the network, allowing the collected data to immediately benefit those affected.

"It's a great learning process for all of us and really motivating because you know where your results are going."