IMMUNOHISTOCHEMICAL LOCALIZATION OF KAPPA-OPIOID RECEPTORS IN THE HUMAN FRONTAL-CORTEX

The cellular and subcellular K opioid receptor distribution in human f rontal cortex was studied using the monoclonal antibody (KA8). kappa o pioid receptor-like immunoreactivity was mainly localized in pyramidal neurons of layers II/III and V. In addition, some round and ovoid neu rons were found immunolabeled mainly in layer VI. At the ultrastructur al level the immunoprecipitate was attached to the cell membrane but w as not associated with synaptic specializations. Furthermore, labeling was present in the neuronal perikarya associated with free ribosomes and in the dendrites partly decorating microtubular structures. Previo us autoradiographic findings remained restricted to the level of lamin ar distribution. By contrast, the monoclonal antibody KA8 provides a u nique tool to study the cerebral kappa opioid receptor distribution on the cellular and subcellular level.