Wednesday, May 16
09:00 - 09:45
The Neurobiology of Stress: From Mechanisms to Interventions
Sonia Lupien, PhD
Scientific Director, Mental Health Institute, University of Montreal
Professor, Department of Psychiatry at University de Montréal
Founder and Director of the Centre for Studies on Human Stress
For the last two decades, science has managed to delineate the mechanisms by which stress hormones (particularly glucocorticoid secretion through activation of the hypothalamic-pituitary-axis) can impact on the human brain. Receptors for glucocorticoids are found in the hippocampus, amygdala and frontal cortex, three brain regions involved in memory processing and emotional regulation. Studies have shown that chronic exposure to stress is associated with reduced volume of the hippocampus and that acute and chronic stress can modulate volumes of both the amygdala and frontal cortex. The negative effects of chronic stress on the hippocampus has led to the 'Neurotoxicity Hypothesis', whereby chronic exposure to stress can lead to hippocampal atrophy. However, recent studies show that reduced hippocampal volume can actually be pre-determined early in life and increase vulnerability to develop stress-related mental health disorders in face of adversity during adulthood (the ‘Vulnerability Hypothesis’). We have recently suggested that exposure to early adversity could delay the development of various brain regions through a neurotoxic process, leading to reduced brain volumes as measured in adulthood. These reduced brain volumes in adulthood could increase vulnerability to develop mental health disorders in the face of adversity during adult life (called the 'Life-Cycle Model of Stress'). I will present new data showing that early exposure to maternal depression has significant impact on brain volumes in 10 years old children, thus giving support to this model. Based on these data, my laboratory is now developing and/or studying the effects of various interventions aiming at decreasing stress hormones levels in children and teenagers in order to prevent the deleterious effects of chronic stress on brain development. I will summarize these studies in conclusion.
Sonia Lupien is the founder and director of the Centre for Studies on Human Stress (www.humanstress.ca), and she holds a position as Senior Investigator Chair on Mental Health in Women and Men from the Canadian Institutes of Health Research.
For the last 20 years, Sonia Lupien has been studying the effects of stress on the human brain, from infancy to adulthood and old age. In her new research projects, she is working on differences between men and women in stress reactivity, and she is developing new educational programs on stress in adolescents and workers. For adolescents, she has developed the ‘DeStress for Success Program", which aims at teaching adolescents making the transition from elementary to high school about ways to control stress. In workers, she has developed the ‘Stress IncÓ’ program which aims at helping worker recognize and control stress by means of a computer program.
Greatly involved in the transfer of scientific knowledge to the public, Sonia Lupien has recently published a book entitled ‘Par amour du stress’ (soon to be translated in english) which aims at helping the public better understand stress as it has been studied for the last 50 years by scientists across the world.