Grant: Doctoral: Vanier Canada Graduate Scholarships

A major goal of neuroscience research is to understand how neural circuits in the brain change during recovery from brain injury or when learning new skills. Existing techniques that study this problem generally permit only the study of a small number of neurons or study anesthetized animals. These restrictions limit the extent to which findings can be generalized to natural behaviour. Optical recording and stimulating techniques hold excellent promise to circumvent this limitation. Specialized dyes applied to the brains of mice, used with high-speed cameras and precise microscopes, allow recording of which neurons are active across large regions of the brain at once. At the same time, lasers can be used to activate any part of the surface of the brain of special lines of mice. Because dyes and laser light are applied to the intact surface of the brain, all neural networks and connections are intact, meaning findings are representative of natural functions. My research will develop innovative use of these techniques to study how the brain recovers from stroke. While scientists know that changes occur in the brain after injury, we don't know what guide these changes. This project will test the idea that a special type of sensory cell that responds to changes in muscle length indicates that changes in the brain are needed and spurs reorganization. A type of mice that has reduced numbers of these cells will be developed. Using the dyes and microscopes described above, the brain activity in these mice will be studied during stepping and walking. Next, a small stroke will be induced in the motor regions of the brains of these mice. The ways that their brains reorganize after this injury will be studied to determine the impact that the lacking sensory cells have on this process. This research will provide valuable information about the fundamental ways that human brains recover and reorganize after stroke and could potentially lead to new rehabilitative therapies.