Free radicals are potentially damaging molecules produced in cells, particularly in response to injury. Certain free radicals cause tissue damage and trigger cell death. To combat the effects of free radicals, healthy people produce adequate quantities of antioxidants, scavenging enzymes that defend cells from free-radical destruction. When a person suffers a stroke, free radicals known as reactive oxygen species may cause cell death in large areas of the brain, resulting in brain damage and disability. It is believed that by increasing the number of antioxidants in the brain, cell death and damage following stroke might be minimized. Sophie Imbeault is working to clarify the role of the transcription factor Nrf2, which regulates the production of antioxidants in the brain. By studying the basic mechanisms underlying Nrf2 activation both during normal functioning and during stroke, she hopes her work will ultimately point to new treatment possibilities for minimizing stroke damage.