IMMUNOHISTOCHEMICAL LOCALIZATION OF THE MU-OPIOID RECEPTORS

Using antibodies generated to the C-terminal 63 amino acids of the clo ned rat mu receptor, the present study examines the distribution of th e mu receptor-like immunoreactivity (li) in perfused rat brain section s. Generally, the localization of the mu receptor-li compares well wit h previous receptor binding studies, with staining observed in such re gions as the caudate-putamen, nucleus accumbens, hippocampus, amygdala , thalamus, superior and inferior colliculi, interpeduncular nucleus, parabrachial nucleus, locus coeruleus, raphe nuclei, nucleus tractus s olitarius, and the dorsal horn of the spinal cord. This distribution i s consistent with the broad number of functions associated with mu rec eptors, including inhibition of sensory transmission and the regulatio n of neuroendocrine and neurotransmitter release.