Neural mechanisms of reward processing and emotion

眶额皮层（OFC）和内侧额叶皮层（MFC）的神经元编码预期和收到的奖励结果的感觉属性，幅度和主观价值。此外，这些区域的神经元活动反映了预期的唤醒，如瞳孔直径所测量的。 决策和唤醒的表征是密切相关的。这些过程如何在单个神经元以及神经回路的水平上相互作用尚不清楚。为了了解OFC和MFC如何影响唤醒和决策，我们记录了动物在做出奖励引导决策时两个区域的神经活动。记录心率（HR）作为唤醒的代表。在完整的动物中，我们发现较高的HR促进了反应时间（RT）。同时，在OFC和MFC的一组神经元选择性地编码的HR独立的奖励幅度的试验的变化。杏仁核损伤后，HR普遍增加，HR和RT之间的关系被逆转。与此同时，有一个MFC神经元编码HR的比例增加。在人口水平上，MFC的编码平衡转向信号HR，这表明一个特定的机制，通过唤醒影响决策。

Neurons in both the orbitofrontal cortex (OFC) and medial frontal cortex (MFC) encode the sensory properties, magnitude and subjective value of expected and received rewarding outcomes. In addition, the activity of neurons in these regions reflects anticipatory arousal, as measured by pupil diameter. Decision-making and representations of arousal are intimately linked. How these processes interact at the level of single neurons as well as neural circuits are unknown. To understand how OFC and MFC influence arousal and decision making, we recorded neural activity from both regions while animals made reward-guided decisions. Heart rate (HR) was recorded as a proxy for arousal. In intact animals we found that higher HR facilitated reaction times (RTs). Concurrently, a set of neurons in OFC and MFC selectively encoded trial-by-trial variations in HR independent of reward magnitude. After amygdala lesions, HR generally increased and the relationship between HR and RTs was reversed. Concurrent with this change, there was an increase in the proportion of MFC neurons encoding HR. At the population level, the balance of encoding in MFC shifted towards signaling HR, suggesting a specific mechanism through which arousal influences decision-making.