New Understanding Of Why Brain Cells Die After Stroke Will Lead To Development Of New Treatments

Scientists at Toronto Western Hospital and the University of Toronto have found a major mechanism that causes brain cells to die from stroke. They discovered that when brain cells are deprived of oxygen and vital nutrients, as happens to parts of the brain affected by a stroke, a special channel on the surface of those brain cells is activated, triggering a lethal chain reaction. The channel, called TRPM7, when activated causes brain cells to produce large quantities of free radicals - toxic molecules that break down the cell's DNA, proteins, and other components. Free radicals also cause TRPM7 to become even more active, causing massive overproduction of free radicals, resulting in death of the brain cell.

In a study published in the December 26 issue of Cell, an international science journal, the scientists also report that they have found a way to interfere with this lethal chain reaction. While brain cells can only survive for a few minutes without oxygen, interfering with the activity of TRPM7 allows brain cells to survive for more than three hours without oxygen and vital nutrients.

With this new understanding, there is now an opportunity to develop new medications that prevent activation of the TRPM7 channel. It will take approximately three years to develop a medication.

"This is a quantum leap forward in understanding how stroke causes brain damage," says Dr. Michael Tymianski, neurosurgeon at the Krembil Neuroscience Centre at Toronto Western Hospital and associate professor of surgery and physiology at the University of Toronto