Oct 13, 2022 | 5 pm | Zoom
David Robbe
Disentangling the many potential functions of the dorsal striatum in rats: from motor skill to vigor and cost.
A prominent theory in system neuroscience is that different forms of memories are stored in different brain regions/networks. Inside this framework, the basal ganglia, and more specifically the dorsal striatum (dS), are supposed to play a critical role in the storage and recall of motor memories. However, in tasks used to probe the dS contribution to procedural memory through perturbation of neuronal activity, it is nearly impossible to disentangle whether behavioral impairments arised from an inability to implement a preserved procedural memory into actions (i.e., a performance deficit) or from a direct alteration of the stored procedural memory (i.e., not remembering what to do) with preserved motor control. Recently, we attempted to address this conundrum and limit the impact of the performance confound by examining the impact of dS lesion in rats performing a series of locomotion-based tasks with varying requirements in terms of movement speed control and procedural memory. On the one hand, we found that dS lesions did not prevent the animals from remembering the procedural steps to follow to successfully perform a previously learned routine. On the other hand, dS lesions changed the kinematic parameters of the routine execution in a way that is well accounted for by an increased sensitivity to effort. Thus, while our work points to a role of the dS in controlling the vigor of goal-oriented motor sequences, it also suggests that such a function might be derived from a more fundamental contribution of this brain region to the sensitivity to movement costs, with potential implication to understand several brain disorders at the interface between movement and motivations.
