RT Journal Article SR Electronic T1 Opposing roles of the dorsolateral and dorsomedial striatum in the acquisition of skilled action sequencing in rats JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.04.15.439935 DO 10.1101/2021.04.15.439935 A1 Karly M. Turner A1 Anna Svegborn A1 Mia Langguth A1 Colin McKenzie A1 Trevor W. Robbins YR 2021 UL http://biorxiv.org/content/early/2021/09/09/2021.04.15.439935.abstract AB The shift in control from dorsomedial to dorsolateral striatum during skill and habit formation has been well established, but whether striatal subregions orchestrate this shift co-operatively or competitively remains unclear. Cortical inputs have also been implicated in the shift towards automaticity, but it is unknown if they mirror their downstream striatal targets across this transition. We addressed these questions using a five-step heterogeneous action sequencing task in rats that is optimally performed by automated chains of actions. By optimising automatic habitual responding, we discovered that loss of function in the dorsomedial striatum accelerated sequence acquisition. In contrast, loss of function in the dorsolateral striatum impeded acquisition of sequencing, demonstrating functional opposition within the striatum. Unexpectedly the medial prefrontal cortex was not involved, however the lateral orbitofrontal cortex was critical. These results shift current theories about striatal control of behavior to a model of competitive opposition, where the dorsomedial striatum acts in a gating role to inhibit dorsolateral-striatum driven behavior.Competing Interest StatementThe authors have declared no competing interest.