A dual-pathway architecture for stress to disrupt agency and promote habit

Chronic stress can change how we learn and, thus, how we make decisions.
Here we investigated the neuronal circuit mechanisms that enable this.
Using a multifaceted systems neuroscience approach in male and female
mice, we reveal a dual pathway, amygdala-striatal neuronal circuit
architecture by which a recent history of chronic stress disrupts the
action-outcome learning underlying agency and promotes the formation of
inflexible habits. We found that the basolateral amygdala projection to
the dorsomedial striatum is activated by rewarding events to support the
action-outcome learning needed for flexible, goal-directed decision
making. Chronic stress attenuates this to disrupt action-outcome learning
and, therefore, agency. Conversely, the central amygdala projection to the
dorsomedial striatum mediates habit formation. Following stress this
pathway is progressively recruited to learning to promote the premature
formation of inflexible habits. Thus, stress exerts opposing effects on
two amygdala-striatal pathways to disrupt agency and promote habit. These
data provide neuronal circuit insights into how chronic stress shapes
learning and decision making, and help understand how stress can lead to
the disrupted decision making and pathological habits that characterize
substance use disorders and mental health conditions.