Off-line consolidation of motor sequence learning results in greater integration within a cortico-striatal functional network

Karen Debas, Julie Carrier, Marc Barakat, Guillaume Marrelec, Pierre Bellec, Abdallah Hadj Tahar, Avi Karni, Leslie G. Ungerleider, Habib Benali, Julien Doyon

The consolidation of motor sequence learning is known to depend on sleep. Work in our laboratory and others have shown that the striatum is associated with this off-line consolidation process. In this study, we aimed to quantify the sleep-dependent dynamic changes occurring at the network level using a measure of functional integration. We directly compared changes in connectivity before and after sleep or the simple passage of daytime. As predicted, the results revealed greater integration within the cortico-striatal network after sleep, but not an equivalent daytime period. Importantly, a similar pattern of results was also observed using a data-driven approach; the increase in integration being specific to a cortico-striatal network, but not to other known functional networks. These findings reveal, for the first time, a new signature of motor sequence consolidation: a greater between-regions interaction within the cortico-striatal system.