Immunohisto- and cytochemical localization of cortical nicotinic cholinoceptors in rat and man.

A monoclonal antibody (WF 6) raised against purified Torpedo nicotinic acetylcholine receptor was applied to study the cellular and subcellular receptor distribution in human and rat neocortex. In both species, immunostaining was most prominent in perikarya and dendrites of the projection neurons in layers III and V. In layer VI fusiform cells displayed immunoreactivity while in layers I, II and IV some round-shaped cells were immunostained. Subcellularly, immunoprecipitate was found in neuronal perikarya, dendrites and in the postsynaptic thickenings, indicating intracellular sites of synthesis, transport and membrane incorporation of receptor protein. The results suggest that WF 6-immunocytochemistry is a useful tool to label nicotinic cholinergic receptors rendering new information about the specific cell-type and subcellular receptor distribution hardly obtainable by using conventional receptor autoradiography.