Central noradrenergic neurons: identification, distribution and synaptic interactions with axons containing morphine-like peptides.

Overview

Perikarya and processes of noradrenergic neurons have been identified in brain by fluorescence histochemistry, radioautography, and immunocytochemistry. The neuronal perikarya are localized in discrete nuclei within the brain stem. Many of these nuclei such as the locus coeruleus send efferent projections to virtually every portion of the central nervous system. Electron-microscopic immunocytochemical studies suggest that the functioning of many of the noradrenergic neurons may be modulated by direct synaptic interactions with neurons containing the opiate-like peptides, methionine (Met5) and leucine (Leu5) enkephalin.