Grant: Project Grant

A stroke is most commonly caused by a blocked blood vessel within the brain, leading to the death of brain cells in the region near the blockage. A major question that scientists have been working on is to determine why some people improve after the stroke, while others do not. Recent studies have shown that in addition to the major stroke, many patients also have a number of smaller strokes, called microinfarcts spread throughout the brain. We predict that these microinfarcts impair brain plasticity and therefore decrease recovery following stroke. Using an animal model, we will study how microinfarcts alter brain plasticity and affect recovery after a major stroke. First, we will study the effects of microinfarcts on normal brain function by mapping out parts of the brain that control movement of the body. Specifically, we will study the part of the brain that can move the forepaw of mice and evaluate how microinfarcts affect the amount of movement produced when this region of the brain is stimulated. Next, we will study how microinfarcts alter recovery after a major stroke. We will measure brain activity as animals perform a reaching task. By imaging the same animals over several days, we can measure the plastic changes that occur in the brain that are responsible for improving motor performance. We will be able to determine if microinfarcts alter the amount of brain plasticity occurring following a major stroke. In our last experiment, we will evaluate if microinfarcts decrease the benefits of rehabilitation after focal stroke. Motor practice improves recovery after stroke, but we predict that microinfarcts will decrease the amount and quality of this motor behavior, resulting in impaired recovery.