The team received a four-year, $1.4 million grant from the National Institute of Neurological Disorders and Stroke for this research.

While most imaging methods are unable to detect signs of brain damage until hours or even days after injury or trauma, DWI can identify changes in the brain within minutes of injury. Shortly after an individual has a stroke, for example, DWI shows the area at risk for permanent injury.

DWI is a magnetic resonance imaging (MRI) technique that is sensitive to the motion of water within the brain. Scientists do not entirely understand the biology underlying DWI's detection of brain damage -- while it is clear that water diffusion is decreased in damaged tissue, the cause of this decrease is not yet understood. One hypothesis is that water motion inside brain cells decreases when the cells are injured.

The School of Medicine team will study three types of cells in search of a better understanding of this powerful tool. First, they will examine immature eggs from the frog Xenopus, which are large enough to directly measure water diffusion.

They also will study a line of tumor cells called HeLa cells and intact rat brains, both from healthy rats and from rats that have had a stroke. The diffusion of water inside the HeLa cells and rat brains will be measured indirectly.