I am broadly interested in how the body responds and adapts to environments, activities and conditions that are associated with reduced oxygen availability. More specifically, I study how the sympathetic nervous system is activated during exposure to low oxygen, and how it acts to control blood flow to critical organs and tissues.
Neural and Cardiovascular Responses to Hypoxia
An acute or chronic reduction in oxygen is a significant physiological stress. A major focus of my research is based on how the body responds during and following reductions in oxygen. During periods of hypoxia both corrective (increased ventilation) and compensatory (blood flow redistribution) mechanisms are activated. The effectiveness of these responses is an important determinant of whether an individual suffers acute or chronic illness.
There is important feedback and cross-talk maintaining balance between corrective and compensatory mechanisms. Ongoing studies in my lab are investigating how ventilation, or the lack thereof, influences sympathetic nervous system regulation during periods of hypoxia.
Blood Pressure Control in Clinical Populations
The organ which detects changes in oxygen in the blood (the carotid body) has been implicated in the development of high blood pressure in a number of clinical populations. The carotid body can become hyperactive in the absence of changes in O2, leading to sympathetic activation and hypertension. Collaborative studies are currently exploring this mechanism in patients with Chronic Obstructive Pulmonary Disease (COPD) and Preeclampsia (a hypertensive pregnancy disorder).
The translation of a stress (e.g. low oxygen) into an appropriate response (e.g. blood flow redistribution) is regulated through a number of steps within a reflex. A portion of my research is devoted to understanding the fundamental ways this communication takes place. My lab specializes in direct recordings of sympathetic nervous system activity (microneurography), as well as multiple techniques for assessing vascular function (e.g. ultrasonography). My lab also uses custom analysis approaches to identify how sympathetic neurons are activated and or recruited, and to identify how a given amount of sympathetic activity affects vascular outcomes (neurovascular transduction) under various conditions.
My research is currently funded by the Natural Sciences and Engineering Research Council of Canada (NSERC), The Canadian Foundation for Innovation (CFI), and The Women and Children’s Health Research Institute (WCHRI).
I currently supervise 1 MSc student studying the influence of breathing and drive to breathe on sympathetic nervous system activity and co-supervise 1 PhD student studying sympathetic nervous system adaptation during pregnancy. I am currently welcoming applications for graduate supervision. I also take on undergraduate practicum students and summer research students.