GRIN2B and depressive disorder: GRIN2B expression is thus lowest in sensory areas such as primary visual and somatosensory cortex, intermediate levels in association cortices such as the dorsolateral prefrontal cortex (dlPFC), and highest in limbic areas such as the subgenual cingulate cortex (SGC) (Burt et al., 2018; Yang et al., 2018), an area associated with mood, visceromotor function, and hyperactivity in depression (Mayberg et al., 2005; Alexander et al., 2019a).