Dopamine in the nucleus accumbens in valence-based learning: is it really important?

Striatal dopamine is widely recognized as a pivotal neuromodulator in reward processing and reinforcement learning. Recent studies have unveiled its significant role in aversive learning as well. However, emerging evidence challenges the notion of uniform dopamine signaling across the striatum in response to valence stimuli and associative learning. The timing, location, and type of dopamine release appear to unlock its diverse effects on neuronal activity and behavior. This review evaluates current literature on dopamine’s role in valence-based learning, with an emphasis on the nucleus accumbens (NAc). It highlights the anatomical and temporal specificity of dopamine signaling across NAc subregions and its influence in diverse facets of valence-based learning. While much is yet to be understood, it is clear that innovative and systematic approaches are required to unravel the intricate mechanisms through which dopamine shapes neuronal activity and rewarding and aversive behaviors. • Striatal dopamine is a key neuromodulator of reward- and aversion-related behaviors. • Dopamine signals in the NAc are anatomically and temporally distinct, potentially encoding distinct aspects of valence-related learning. • Dopamine signals in the NAc go beyond classical reward predicting error. • The field needs to perform additional studies to unravel the complexity of dopamine's influence on valence-related learning.