Grant: Operating Grant

It is now estimated that a North American child stands a 1 in 3 chance of becoming diabetic. This staggering figure has an enormous cost, both for the general population that must cover diabetes related health care costs (15.6 billion per year in Canada) and for the individual that will likely suffer disabling complications. For example, people with diabetes are 2-4 times more likely to suffer a stroke and their prognosis for recovery is very poor relative to the general population. In our previous 3 year CIHR grant, we showed that recovery of paw function after stroke was impaired in diabetic mice, which could not be rescued by insulin therapy. Furthermore, poor stroke recovery was not associated with a larger stroke, but rather, profound impairments in how surviving brain regions re-organized their function after stroke. At the present time, very little is known about how diabetes affects the circulation of blood in the brain. Proper circulation is crucial for normal brain function as well as recovery from stroke. The primary goal of the current research proposal will be to use live animal imaging technologies that will allow us to visualize blood flow, blood vessel leakage and remodeling in the diabetic mouse brain before and after a stroke. We will then try to link changes in the circulatory system with the re-wiring of neuronal circuits in parts of the brain important for stroke recovery. Given our preliminary data showing that diabetes leads to more leaky blood vessels and altered blood flow after stroke, we will explore the possibility that too much of a blood vessel related growth factor (called VEGF) may be responsible for poor stroke recovery in diabetics. Ultimately, the proposed project will generate new information regarding the effects of diabetes on the brain, which will stimulate new treatment options for those Canadians suffering from diabetes related sequeleae.