Figure 4.

Mood and reward circuitry. A simplified depiction of neural circuits that have been implicated in the pathophysiology of depression. The glutamatergic (green) projections to the nucleus accumbens (NAc) from hippocampus (HPC), amygdala, and prefrontal cortex (PFC) are prominently featured, and many subcortical regions that mediate reward, fear, and motivation are also depicted. This diagram also shows the innervation of many regions by monoaminergic projections from the ventral tegmental area ([VTA], blue dopaminergic projections to NAc, amygdala, PFC), as well as yellow noradrenergic projections from the locus coeruleus (LC) and serotonergic projections from the dorsal raphe (DR). The NAc also sends GABAergic (red) projections to the hypothalamus (not pictured), VTA, and substantia nigra (SN), and GABAergic interneurons are found within the HPC (and other structures). This diagram, while not exhaustive, highlights some of the major circuits involved in depression and referenced throughout this work.