Contrôle et réactivation de la marche par le retour sensoriel après une lésion de la moelle épinière

 

Alain Frigon

Université de Sherbrooke

 

Domaine : neurosciences, santé mentale et toxicomanies

Programme Chercheurs-boursiers - Junior 2

Concours 2019-2020

The ability to move is one of the defining characteristics of animal life, including humans. The overall goal of my research program is to better understand how we control movement, in particular the ability to walk. To move, cells within our spinal cord, called motoneurons, send electrical impulses via nerves to muscles, causing them to contract. Injuries or diseases of the nervous system often produce movement disorders. For example, after a spinal cord injury, walking is often impaired and in the most severe cases, the limbs are paralyzed. However, in animal models of complete spinal cord injury, the legs can recover an involuntary walking pattern after a few weeks of treadmill training.

This remarkable recovery, first shown in cats, is due to the presence of a locomotor centre within the spinal cord that generates the basic pattern of walking without signals from the brain. During treadmill training, receptors in muscles and skin of the legs that respond to stretch and the pressure applied by body weight send signals to the spinal cord. These signals in turn reactivate the locomotor centre that controls walking. In the next four years, my research will continue exploring how signals from receptors located in muscles and skin control the locomotor centre and how this control changes after spinal cord injury. This knowledge will help guide the development of new training approaches and bio-engineered devices to reactivate the locomotor centre within the spinal cord after spinal cord injury.