Medium spiny neurons (MSNs) of mice show opposing activities upon the initiation of a food-seeking lever press task. Ventromedial striatal (VMS)-MSNs are inhibited but ventrolateral striatal (VLS)-MSNs are activated; these activities mediate action selection and action initiation, respectively. To understand what input shapes the opposing MSN activities, here, we monitor cortical input activities at the cell population level and artificially reverse them. We demonstrate that the ventral hippocampus (vHP) and the insular cortex (IC) are major inputs to the VMS and VLS, both projections show silencing at the trial start time, and the vHP-VMS and IC-VLS pathways form functionally coupled input-output units during the task. Of note, the upstream IC silencing is converted to the downstream VLS-MSN activation. We find biased localization of striatal parvalbumin-expressing interneurons (PV INs) and verify PV IN-dependent feedforward architecture in the VLS. Our results reveal a distinct mode of cortico-striatal signal conveyance via feedforward disinhibition in behaving animals.

小鼠的中棘神经元（MSN）在寻求食物的杠杆按压任务启动时显示相反的活动。抑制腹内侧纹状体（VMS）-MSN，但激活腹侧纹状体（VLS）-MSN。这些活动分别介导了动作选择和动作发起。为了了解什么输入会形成对立的MSN活动，在这里，我们在细胞群体水平上监视皮质输入活动并人为地逆转它们。我们证明腹侧海马（vHP）和岛状皮层（IC）是VMS和VLS的主要输入，这两个预测都显示在试验开始时沉默，并且vHP-VMS和IC-VLS通路形成了功能耦合的输入-任务期间输出单位。值得注意的是，上游IC沉默转换为下游VLS-MSN激活。我们发现表达纹状小白蛋白的中间神经元（PV INs）的偏向性，并验证VLS中依赖PV IN的前馈结构。我们的研究结果揭示了行为动物中通过前馈去抑制而实现的皮质纹状体信号传递的独特模式。