Aversion hot spots in the dopamine system

Abstract

Through the development of optogenetics and other viral vector-based technologies, our view of the dopamine system has substantially advanced over the last decade. In particular, progress has been made in the reclassification of dopamine neurons based on subtypes displaying specific projections, which are associated with different features at the anatomical, molecular and behavioral level. Together, these discoveries have raised the possibility that individual groups of dopamine cells make a unique contribution to the processing of reward and aversion. Here, we review recent studies that have identified non-canonical dopamine pathways that are excited in response to aversive stimuli, including dopamine projections to the ventromedial shell of the nucleus accumbens, prefrontal cortex, tail of the striatum, and amygdala.

Figure 1.. Aversion pathways within the dopamine system.

In the schematic overview, dopamine subpopulations that have been shown to be activated by aversive stimuli are highlighted based on their anatomical connectivity between ventral tegmental area (VTA) and substantia nigra (SN) and projection targets in the medial prefrontal cortex (mPFC), ventromedial nucleus accumbens shell (vNAcMed), basolateral amygdala (BLA) and tail of the striatum (TS). Dopamine neurons in the dorsal raphe nucleus and periaqueductal gray (PAG) project to the bed nucleus of the stria terminalis (BNST) and central nucleus of the amygdala (CeA) (BNST and CeA projections are not shown).