IMMUNOHISTOCHEMICAL LOCALIZATION OF THE KAPPA(1) OPIOID RECEPTORS

Using antibodies generated to the C-terminal 41 amino acids of the clo ned rat kappa receptor, the present study examines the distribution of the kappa(1) receptor-like immunoreactivity (li) using immunohistoche mical techniques. The localization of the kappa(1) receptor staining g enerally corresponds well to previous receptor binding and in situ hyb ridization studies, with stained fibers and/or cells observed in such regions as the endopiriform nucleus, claustrum, nucleus accumbens, olf actory tubercle, bed nucleus stria terminalis, medial preoptic area, p araventricular, supraoptic and lateral hypothalamus, median eminence, thalamus, medial amygdala, parabrachial nucleus, nucleus of the solita ry tract, and the superficial layers of the spinal cord. This localiza tion is consistent with the wide range of functions associated with ka ppa(1) receptors, including analgesia and hormonal regulation.