Abstract
The shift in control from dorsomedial to dorsolateral striatum during skill and habit formation is 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. Do cortical inputs mirror their downstream striatal targets across this transition? We addressed these questions using a five-step heterogeneous action sequencing task that is optimally performed by automated chains of actions. By optimising automatic responding, we discovered that loss of function in the dorsomedial striatum accelerated 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 behaviour to a model of competitive opposition, where the dorsomedial striatum acts in a gating role to inhibit dorsolateral-driven behaviour.
Competing Interest Statement
The authors have declared no competing interest.
