Dr. MacVicar has been a leader in the development and application of advanced brain imaging techniques during his career. He discovered that brain tissue is more transparent in infrared wavelengths, which are used widely to visualize nerve cells in intact brain tissue. With Image Science, a company he founded, he developed software that was widely used to control scientific image acquisition equipment and imaging analysis.
The MacVicar lab has implemented two-photon microscopy and uncaging techniques to investigate and visualize complex interactions in the brain. The application of advanced imaging techniques has allowed his lab to make significant contributions to our understanding of how neuronal activity is regulated and how to protect nerve cells during stroke.
ROLES FOR CALCIUM SIGNALING IN ASTROCYTES
This research is funded by a CIHR operating grant (2005-2011) and has revealed a major role for astrocytes in the regulation of cerebral blood flow. The experiments will continue the investigations into the mechanisms by which astrocyte regulation of blood vessel tone is mediated by the calcium dependent liberation of arachidonic acid and the subsequent metabolites of arachidonic acid.
SYNAPTIC AND NON-SYNAPTIC REGULATION OF NEURONAL EXCITABILITY
These experiments are funded by a CIHR operating grant (2005-2011) and are investigating the modulation of neuronal excitability via alterations of r-type calcium currents and insertion of trpc5 channels, activation of pannexin hemichannels in hippocampal pyramidal neurons and the contribution to seizure discharges, and alterations of synaptic efficacy by immune activation of microglia and astrocytes.
MECHANISMS MATCHING THE BRAIN’S VASCULAR ENERGY SUPPLY TO NEURAL ACTIVITY, AND THEIR FAILURE IN DISEASE
These experiments are part of the Leducq Fondation Transatlantic Network of Excellence (2008-2013). Directed by Dr. MacVicar, this group of investigators in North America and in Europe will focus on interventions to reduce the pathological decreases in cerebral blood flow that occur after stroke or other vascular insults such as spreading depression associated with migraine or brain trauma. The experiments will determine the roles for astrocytes, pericytes and neuronal inputs in modifying the vascular response to neuronal activity during these pathological events.
TARGETING CELL DEATH
These experiments funded by the Canadian Stroke Network (2008-2010) are focused on determining the best strategies to reduce the impact of ion channel activation and inflammatory processes in triggering cell death following stroke.