Dopamine projections to the basolateral amygdala drive the encoding of identity-specific reward memories

Abstract

ABSTRACTTo make adaptive decisions, we build an internal model of associative relationships in the environment and use it to predict specific forthcoming outcomes. Detailed stimulus-outcome memories are a core feature of such cognitive maps, yet little is known of the neuronal systems that support their encoding. We used fiber photometry, cell-type and pathway-specific optogenetic manipulation, Pavlovian cue-reward conditioning, and a decision-making test in male and female rats, to reveal that ventral tegmental area dopamine (VTADA) projections to the basolateral amygdala (BLA) drive the encoding of stimulus-outcome memories. Dopamine is released in the BLA during stimulus-outcome pairing and VTADA→BLA activity is necessary and sufficient to link the identifying features of a reward to a predictive cue, but does not mediate general value or reinforcement. These data reveal a dopaminergic pathway for the learning that supports adaptive decision making and help understand how VTADA neurons achieve their emerging multifaceted role in learning.