Contribution of the cerebellum to postural control and motor learning
Vincent Villette
Equipe Transmission inhibitrice dans le cerveau – IBEN, Paris

Résumé
In our daily lives, a large number of different muscle contractions are coordinated unconsciously to ensure postural control. This task is not trivial, but essential for establishing stable states before ballistic movements that are consciously planned and quickly executed. The cerebellum is well positioned to coordinate whole-body coordination of muscles contractions, rapidly control the neural activities required for ballistic actions, and support motor learning. However, cerebellar microcircuits require further understanding and optimized monitoring of activity during behavioral tasks involving multi-segmental and rapid movements in order to better understand the cerebellum’s contribution to postural control.
Focusing on postural adjustment, which is a major function of the vermal part of the cerebellar cortex, we first looked at the activity of the inferior olive, which is the main driver of cerebellar motor learning. Classic models of cerebellar learning have recently been challenged by observations indicating a gradual olivary discharge that can be distributed in space and time. Using ULoVE, we record the calcium activity of several Purkinje cell dendrites during postural learning in a new environment with millisecond temporal precision. We find that movement-related IO activity occurs in two phases, with prolonged modulation preceding a sharp response around the onset of ballistic movement. While prolonged modulation recapitulates an initial exaggeration of movement and converges upon parallel learning, the sharp response evolves to reflect the kinematics of movement. We identify sequences of CF events occurring during periods of movement that may be a substrate for cerebellar plasticity and thus support motor learning in the cerebellum.

Invité par Michel Picardo
Lundi 3 novembre à 11h, salle de conférence de l’Inmed