Strokes often cause brain damage that can severely affect motor function, particularly fine movements of the hands and digits. The motor cortex is the main brain area issuing commands for voluntary hand movements. This brain area, when damaged by a stroke, has the ability to adapt by forming new connections in a way that can help the brain compensate for the damage. This ability to adapt, or neuroplasticity, is improved by therapeutic exercises, but also by different factors that can vary depending on sex.
Namely, the neurons releasing dopamine, responsible for the feelings of reward, pleasure and addiction, have a very important function to regulate neuroplasticity. However, the connections of dopamine neurons are known to differ substantially between male and females in both animals and humans. Therefore, we believe that the dopamine neurons could greatly contribute to neuroplasticity within the motor cortex and improve motor recovery after stroke in a sex-dependent manner.
The influence of dopamine neurons on the motor cortex has been very little studied. We proposed in a previously funded investigation to examine the role of dopamine centers for motor recovery after stroke in laboratory rats. Here, we propose to expand this investigation to examine sex-differences in the anatomy of dopamine release in the motor cortex, and its influence on motor recovery after stroke.
We propose innovative methods to answer this original questions. Specifically, we will use state-of-the-art cell labeling and imaging technologies to reveal sex differences in anatomy. We will also use highly selective tools to manipulate the motor cortical dopamine release in order to reveal their contribution to motor recovery. Our experiments will provide new and detailed knowledge essential for the future development of better sex-based therapies after stroke.