Nucleus Accumbens Processing of Reward-predictive Cues

伏隔核(NAC)是神经回路的重要组成部分，负责 以目标为导向的行为(如寻求毒品)对环境刺激的反应 预测奖励的可用性。这里提出的研究是对生理机制的研究。 NAC通过它来处理刺激并影响刺激将导致目标导向的概率 行为。NAC神经元的放电可分为三大类：线索诱发的放电， 与操作者有关的射击增加或减少，以及与奖励有关的射击改变。这些信息 将通过更改提示包含的信息来确定这些模式包含的信息(对于 例如，去哪里获得奖励)，并检查神经反应是否以及如何因此 变化。我们将明确研究运动行为和NAC神经元放电之间的关系， 尤其是当它与驱动目标导向行为的线索有关时。此外，NAC在多大程度上 我们将研究神经元对线索所预测的奖励进行编码。 尽管大量的行为药理学和解剖学研究表明， NAC的核、壳和嘴极在行为上是不同的，很少有电生理研究发现 这些区域的神经元在已知控制或控制的行为任务中的反应方式的差异 因此，这个项目的第二个目标是确定NAC的激发模式是如何 分布在NAC的各个次区域。 这项工作的第三个主要目标是确定多巴胺能投射到NAC在 在自然的奖赏行为中调节神经放电。微量注射多巴胺拮抗剂 在NAC内部打算改变特定的放电模式将被用来建立神经之间的因果联系 活动和寻求奖励的行为。这些实验将使我们更全面地了解 NAC神经元和在NAC内释放的多巴胺参与了自然奖赏背后的过程。 这样的理解对于确定药物奖励的神经机制是至关重要的。

The nucleus accumbens (NAc)is an important contributor to the neural circuitry responsible for the engagement of goal-directed behavior (such as drug seeking) in response to environmental stimuli that predict reward availability. The research proposed here is an investigation of the physiological mechanisms by which the NAc processes stimuli and influences the probability that a stimulus will result in goal-directed behavior. The firing of NAc neurons can be divided into three broad categories: cue-evoked discharges, operant-related increases or decreases in firing, and reward-related firing changes. The information contained by these patterns will be determined by changing the information contained by the cue (for instance, where to go to get the reward) and examining whether and how the neural responses consequently change. The relationship between locomotor behavior and NAc neuron firing will be explicitly examined, particularly as it relates to cues that drive goal-directed behavior. In addition, the degree to which NAc neurons encode the reward predicted by cues will be examined. Although a great deal of behavioral pharmacology and anatomy research suggests that the roles of the NAc core, shell and rostral pole in behavior are different, few electrophysiological studies have identified differences in how neurons in these regions respond during behavioral tasks known to be controlled or influenced by the NAc.Therefore, a second goal of this project is to determine how NAc firing patterns are distributed among the subregions of the NAc. A third major goal of this work is to establish the role of the dopaminergic projection to the NAc in modulating neural firing during natural reward-seeking behavior. Microinjection of dopamine antagonists within the NAc intended to alter specific firing patterns will be used to establish a causal link between neural activity and reward-seeking behavior. These experiments will lead to a more complete understanding of how NAc neurons, and dopamine released within the NAc, contribute to the processes underlying natural reward. Such an understanding is essential for the determination of the neural mechanisms of drug reward.