Interactions between the mediodorsal thalamus and the prefrontal cortex are critical for cognition. Studies in humans indicate that these interactions may resolve uncertainty in decision-making¹, but the precise mechanisms are unknown. Here we identify two distinct mediodorsal projections to the prefrontal cortex that have complementary mechanistic roles in decision-making under uncertainty. Specifically, we found that a dopamine receptor (D2)-expressing projection amplifies prefrontal signals when task inputs are sparse and a kainate receptor (GRIK4) expressing-projection suppresses prefrontal noise when task inputs are dense but conflicting. Collectively, our data suggest that there are distinct brain mechanisms for handling uncertainty due to low signals versus uncertainty due to high noise, and provide a mechanistic entry point for correcting decision-making abnormalities in disorders that have a prominent prefrontal component^2,3,4,5,6.

内侧丘脑和前额叶皮层之间的相互作用对认知至关重要。对人类的研究表明，这些相互作用可以解决决策中的不确定性¹，但具体机制尚不清楚。在这里，我们确定了前额叶皮层的两个不同的内侧投射，它们在不确定性下的决策中具有互补的机制作用。具体来说，我们发现当任务输入稀疏时，表达多巴胺受体 (D2) 的投射会放大前额叶信号，而当任务输入密集但相互冲突时，表达投射的红藻氨酸受体 (GRIK4) 会抑制前额叶噪声。总的来说，我们的数据表明，大脑有不同的机制来处理由低信号引起的不确定性和由高噪声引起的不确定性，并为纠正具有突出前额叶成分的疾病的决策异常提供了一个机制切入点^{2,3,4 ,5,6}。