Dr. Roger Thompson
University of Calgary
The Heart and Stroke Foundation of Canada (HSFC)'s Henry J. M. Barnett Scholarship is awarded to a highly rated New Investigator working in the area of stroke research.
The mystery channel
This year's Barnett scholar believes a neuron channel holds the key to understanding what goes on in the brain during stroke.
Scientists have long understood what causes the most common type of stroke: the blood flow to the brain is blocked by a clot. They also know what happens next: a massive number of brain cells quickly collapse after being deprived of oxygen and glucose, leading to death or disability.
What scientists haven’t been able to figure out is exactly how it happens.
Dr. Roger Thompson, the 2008-09 HSFC Barnett Scholar, hopes to change that. And he may have the inside track on stroke-triggered cell death: a little-understood neural cell channel called pannexin-1.
The Barnett Scholarship will enable Dr. Thompson, an assistant professor at the University of Calgary’s Hotchkiss Brain Institute, to build on findings he published in Science two years ago that opened up a new chapter in interpreting the intricacies of stroke.
His work has added another critical piece to understanding that necrosis – the rapid death of brain cells – is not just the blood-starved brain going haywire, but a programmed pattern of events.
“Traditionally, it’s been thought that the cell membrane breaks down and the cell dies – and that you can’t control it,” says Dr. Thompson. “But there is more and more evidence, from my work and other researchers around the world, to indicate that there is a sequence of steps occurring and that by understanding that sequence we might be able to develop some novel interventions.”
When the brain is functioning well, the neurons carry the electrical charges that transmit messages or signals back and forth like a well-oiled machine. Cation (pronounced cat eye on) channels on the cell membranes open and close to allow positively charged molecules like sodium and calcium to enter and potassium to exit.
When the brain is deprived of blood, however, this machine-like organization begins to shut down. The cells overload themselves with calcium, causing death. Dr. Thompson identified pannexin-1, a veritable giant among cation channels, as crucial to the cell-death process. It opens just before cell death.
“I think pannexin-1 is going to turn out to be a critical player in rapid cell death,” says Dr. Thompson. “If we can understand how it is reacting to oxygen deprivation, then we can understand how the brain cells are dying during stroke.”
Dr. Thompson’s long-term goal is to establish pannexin-1 as a target for new drugs to stop cell death when stroke hits.
“The ideal situation might be to develop a drug for people who are at risk for stroke – people who have already had small strokes or ischemic (restricted blood flow) events. These people could take a drug that stays in their system until a stroke occurs. Then it would block the pannexin-1 channel from opening.”
Fast facts about: Dr. Roger Thompson
accepted a faculty position at the University of Calgary in the spring of 2008.
misses Vancouver's Kitsilano Beach but loves being close the Rockies.
Quote: “The ultimate goal is to identify new targets for drugs that stop cell death. I think developing a drug is quite feasible.”