Neural mechanisms linking need to reward

摘要 行为是由奖励驱动的，而最有力的奖励是那些满足生理需求的奖励。为 几十年来，神经科学家一直在研究中脑多巴胺系统，以了解奖赏和下丘脑 了解内部需求感知的电路。但这两个神经系统是如何相互作用而产生 人们对饮食等行为仍然知之甚少。最近，我们使用了一些方法来 同时进行神经记录和操作，以直接观察两者之间的通信 系统。我们还绘制了它们各自从肠道接收到的信号，以响应食物的摄入和 体液。这揭示了饥饿和口渴对多巴胺系统有很强的调节作用，但它们的调节方式不同 方法和可能涉及不同的电路机制。我们在此建议在这些发现的基础上 系统地描绘这些需要和奖励的神经回路是如何在大脑中相互作用的。在目标1中，我们 通过记录这些电路在多个层次上的动态变化，研究这些电路如何代表内部需求 在不同的生理状态下进行分析，并进一步测量这些动态如何受到 有针对性的电路操作。在目标2中，我们调查了这些电路如何使用有关身体需求的信息 通过监测和控制他们在学习过程中的活动来推动对食物的学习。在《目标3》中， 我们调查这些电路如何使用关于内部状态的信息来驱动动机，通过监控和 在动物必须评估相互竞争的需求和奖励的任务中操纵它们的活动。这些 研究将提供对身体需求信息利用机制的基本见解 由大脑产生学习和动力。

Abstract Behavior is motivated by reward, and the most powerful rewards are those that satisfy a physiologic need. For decades, neuroscientists have studied the midbrain dopamine system to understand reward and hypothalamic circuits to understand sensing of internal needs. But how these two neural systems are interact to give rise to behaviors like eating and drinking remains poorly understood. Recently, we have used approaches for simultaneous neural recording and manipulation to observe directly the communication between these two systems. We have also mapped the signals they each receive from the gut in response to ingestion of food and fluids. This has revealed that hunger and thirst powerfully modulate the dopamine system, but do so in different ways and likely involve distinct circuit mechanisms. We propose here to build on these findings to systematically delineate how these neural circuits for need and reward interact in the brain. In Aim 1, we investigate how these circuits represent internal needs, by recording their dynamics at multiple levels of analysis under different physiologic states, and further measuring how those dynamics are influenced by targeted circuit manipulations. In Aim 2, we investigate how these circuits use information about bodily needs to drive learning about food, by monitoring and manipulating their activity during the learning process. In Aim 3, we investigate how these circuits use information about internal state to drive motivation, by monitoring and manipulating their activity during tasks where animals must evaluate competing needs and rewards. These studies will provide fundamental insight into the mechanisms by which information about body needs is utilized by the brain to generate learning and motivation.