locus coeruleus (LC) is a small region of the dorsal and rostral pons that is the primary source of norepinephrine in the brain. It has dense innervation to the thalamus and the amygdala, as well as less dense connections to the neocortex, hippocampus, cerebellum, and spinal cord. LC production of norepinephrine is important for memory encoding and consolidation as well as retrieval.

The substantia nigra is one of the major sources of dopamine. The nucleus basalis of Meynert is a major source of acetylcholine in the brain. The raphe nuclei are a major source of serotonin. The interstitial nucleus of Cajal is involved in many aspects of extra-ocular eye movements, especially eccentric gaze holding.