Project Summary/Abstract The brain uses two strategies to make decisions. Goal-directed decision making relies on prospective consideration of potential outcomes and consequences, using learned action-outcome associations. On the other hand, habits are reflexive behaviors executed without forethought of their consequences. Goal-directed learning is more flexible, but cognitively taxing. Habits require less cognitive control but are relatively inflexible. Balance between these two processes allows behavior to be adaptive when needed, but efficient when appropriate. Dysfunction in this balance or an overreliance on habits causes maladaptive decision making that characterizes substance use disorder and other psychiatric conditions. Despite the importance to understanding adaptive and maladaptive decision making, little is known about the neural circuitry that supports action-outcome learning and habit formation. Recent research in rodents and humans has implicated midbrain dopamine neuron activity in both goal-directed and habit learning. Midbrain dopamine neurons burst fire to unexpected rewards. This signal has been interpreted as the prediction error term needed for habit formation. Recently, dopamine neurons also been found to be involved in aspects of goal-directed learning. It is currently unknown how dopamine could support these two, opposing forms of learning. One way dopamine might achieve this multifaceted function is through projections to subregions of the amygdala. The basolateral amygdala (BLA) has long been known to be involved in goal-directed learning and the central amygdala (CeA) has been implicated in habit formation. Both BLA and CeA receive direct inputs from the lateral ventral tegmental dopamine neurons (VTADA). I will conduct critical, in depth, and hypothesis-driven investigation of the contribution of dopaminergic projections to the basolateral amygdala and central amygdala and their contributions to goal-directed and habit learning. I will receive training in cell-type and projection-specific optogenetic manipulation, fiber photometry dopamine monitoring, and behavioral procedures root in learning theory to diagnose the content of learning and decision strategies. In Aim 1, I will apply in vivo fiber photometry imaging and optogenetic manipulation during a sophisticated behavioral paradigm to characterize the function of the VTADABLA pathway and its necessity for action-outcome goal-directed learning. In Aim 2, I will also apply in vivo fiber photometry dopamine imaging and optogenetic manipulation to uncover the function of VTADACeA pathway and its necessity for habit formation. Completing this project at UCLA ensures I will have access to a highly collaborative network of leading neuroscientists to receive project feedback and training. This award will provide training to help launch me into an independent career role studying maladaptive decision making and its implications for addiction.