Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
Cell. 2021 Dec 22;184(26):6344-6360.e18. doi: 10.1016/j.cell.2021.11.019. Epub 2021 Dec 9.
The anterior insular cortex (aIC) plays a critical role in cognitive and motivational control of behavior, but the underlying neural mechanism remains elusive. Here, we show that aIC neurons expressing Fezf2 (aIC), which are the pyramidal tract neurons, signal motivational vigor and invigorate need-seeking behavior through projections to the brainstem nucleus tractus solitarii (NTS). aIC neurons and their postsynaptic NTS neurons acquire anticipatory activity through learning, which encodes the perceived value and the vigor of actions to pursue homeostatic needs. Correspondingly, aIC → NTS circuit activity controls vigor, effort, and striatal dopamine release but only if the action is learned and the outcome is needed. Notably, aIC neurons do not represent taste or valence. Moreover, aIC → NTS activity neither drives reinforcement nor influences total consumption. These results pinpoint specific functions of aIC → NTS circuit for selectively controlling motivational vigor and suggest that motivation is subserved, in part, by aIC's top-down regulation of dopamine signaling.
岛前皮质（aIC）在行为的认知和动机控制中起着关键作用，但潜在的神经机制仍难以捉摸。在这里，我们表明表达 Fezf2（aIC）的 aIC 神经元（即皮质脊髓束神经元）通过投射到脑干孤束核（NTS）来发出信号，激发动机活力并激发寻求需求的行为。aIC 神经元及其突触后 NTS 神经元通过学习获得预期活动，该活动编码感知到的价值和采取行动以满足生理需求的活力。相应地，aIC→NTS 电路活动控制活力、努力和纹状体多巴胺释放，但前提是该行为是学习得来的，并且结果是需要的。值得注意的是，aIC 神经元不代表味觉或效价。此外，aIC→NTS 活动既不能驱动强化，也不能影响总消耗量。这些结果明确指出了 aIC→NTS 电路的特定功能，用于选择性地控制动机活力，并表明部分动机是由 aIC 对多巴胺信号的自上而下调节来维持的。
