Domain skills | Skill domains. Training is often required for acquiring a new motor skill. Learning is not linear and if a first phase may be gratified by rapid improvements, a second phase is often more tedious with incremental refinements. But what’s behind these processes? Here, the authors found that, in mice trained to walk on a rotating barrel, changes in networks organization occured first, during the early phase of training, in the associative part of striatum and developped later on in the sensorimotor part of striatum. In the latter, changes seemed to amount to the specialization of small striatal sub-domains, persisting months after training. The neuronal implementation of the saying that one never forgets how to ride a bike. (by I. Bureau )
Scientific abstract: Motor skill learning requires the activity of the dorsal striatum, with a differential global implication of the dorsomedial and dorsolateral territories. We investigate here whether and how specific striatal neurons encode the acquisition and consolidation of a motor skill. Using ex vivo two-photon calcium imaging after rotarod training, we report that highly active (HA) striatal populations arise from distinct spatiotemporal reorganization in the dorsomedial (DMS) and dorsolateral (DLS) striatum networks and are correlated with learning performance. The DMS overall activity decreases in early training, with few and sparsely distributed HA cells, while the DLS shows a progressive and long-lasting formation of HA cell clusters. These reorganizations result from reinforcement of synaptic connections to the DMS and anatomical rearrangements to the DLS. Targeted silencing of DMS or DLS HA cells with the cFos-TRAP strategy strongly impairs individual performance. Our data reveal that discrete domains of striatal populations encode acquisition and long-lasting retention of a motor skill.
Authors: Nagham Badreddine, Gisela Zalcman, Florence Appaix, Guillaume Becq, Nicolas Tremblay, Frédéric Saudou, Sophie Achard and Elodie Fino
Published in Cell Reports, 2022