Killam Seminar Series: Capillaries, BOLD, and Brain Disorders

Speaker: Leif Østergaard, MSc, MD, PhD, DMSc

Director, Center of Functionally Integrative Neuroscience, and Lundbeck Foundation and Clinical Professor, Department of Clinical Medicine, Aarhus University, Denmark

Registration: available now on Eventbrite

Livestreaming via Vimeo: Vimeo

Abstract: What is the role of capillaries in neurovascular coupling? Does capillary dysfunction contribute to the pathophysiology of cerebrovascular diseases and Alzheimer’s Disease? The Killam Seminar discusses how capillary transit-time heterogeneity (CTH) affects the transport of oxygen from blood into tissue – and how disease-related capillary changes may limit tissue oxygenation in aging and disease. In brain tissue, oxygen availability is traditionally inferred from the regional cerebral blood flow (CBF). Tissue oxygen uptake, however, is limited by blood’s transit time – the time available for blood-tissue diffusion exchange before blood returns to the heart. Therefore, as CBF increases to meet metabolic demands during brain work, oxygen extraction becomes less efficient in parallel. The seminar describes how higher CBF and homogenization of capillary flow patterns (lower CTH), combined, affect oxygen availability in brain tissue and the blood oxygen level dependent (BOLD) contrast utilized by functional MRI. Theoretically, age-, risk factor-, and disease-related deterioration of capillary function can cause severe tissue hypoxia, even in the absence of any blood flow-limiting conditions per se. The Seminar will summarize recent observations of capillary flow patterns by MRI in human brain and by optical imaging techniques in rodents, and discusse their significance in the context of aging, stroke and dementia.

The Killam Seminar Series at The Neuro

Supported by the generosity of the Killam Trusts, The Neuro’s Killam Seminar series hosts outstanding guest speakers whose research is of interest to the scientific community at The Neuro and McGill University.

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