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
VTADA¿BLA 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 VTADA¿CeA 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.