Mécanismes de récupération de la marche dans des modèles animaux d'atteinte médullaire: rôle du système corticospinal

 

Marina Martinez

Centre de recherche de l'Hôpital du Sacré-Coeur de Montréal

 

Domaine : Neurosciences, santé mentale et toxicomanies

Programme chercheurs-boursiers - Junior 1 

Concours 2016-2017

About 86,000 Canadians live with a spinal cord injury (SCI), and more than 4,300 new cases arise every year. For SCI individuals, limitations in sensory-motor activities such as walking and posture severely affect their quality of life. In most cases, patients have an incomplete injury that spares some connections between the brain, which initiates movements, and the spinal circuits, which generate them. These patients can eventually recover some motor functions with time but that recovery is often incomplete. One of the most promising avenue is to take advantage of the remaining communication pathways between the brain and the spinal cord and that could potentially be activated in order to restore function. My goal is to study how brain structures with partial connectivity to the spinal cord, and particularly the motor cortex, facilitate recovery of walking after SCI. We will use a well-established rat model of SCI in which locomotion is progressively re-expressed over five weeks.

While this short time course does not mimic recovery in humans, it facilitates exploration of the underlying biological mechanisms. By combining innovative paradigms to manipulate cortical activity with behavioural, electrophysiological and neuroanatomical techniques, we will study the mechanisms by which the cortex affects the spinal circuits that generate stepping after SCI. We will then harness these mechanisms to foster and enhance recovery of walking by testing cortical stimulation protocols. Our experiments will provide a comprehensive examination of the role of the motor cortex and the mechanisms through which it influences locomotor recovery after SCI. This proposal has the potential to expand our knowledge on the neural basis of recovery after SCI. Activity-based neurorehabilitation and brain stimulation protocols can be developed to harness cortical activity that may catalyze functional recovery, e.g. walking and posture, following SCI.