Grant: CIHR New Investigator

A stroke is a vascular lesion within the brain. Following a stroke located within the motor cortex, patients have several deficits including loss of upper extremity function. However, patients undergo substantial motor recovery in the weeks and months following the lesion. One hypothesis, for which there is now remarkable support, is that the recovery is dependent upon adaptive reorganization of intact, remaining brain structures. The changes in the hemisphere that had sustained the lesion (ipsilesional) are generally believed to be beneficial to the recovery. Conversely, the role of the reorganization that occurs in the hemisphere opposite to the lesion (contralesional) is controversial. Some studies conclude that plasticity in that hemisphere supports recovery, while others conclude that it actually interferes with it. The goal of the present project is to study the nature of the reorganization in the contralesional hemisphere in order to understand how it can either participate or interfere in recovery. This will be achieved using single-neuron recording techniques in a primate model of stroke. This project is designed to address particularly pressing clinically relevant questions and the information it will generate will help to refine current experimental protocols in humans. The knowledge of physiological principles underlying normal and abnormal function is instrumental in the refinement of effective clinical practice aiming at the maximization of recovery following stroke.