Characterization and autoradiographic localization of TRH receptors in sections of rat brain.

Receptors for thyrotropin-releasing hormone (TRH) in rat brain have been localized autoradiographically by exposing tritium-sensitive film to sections labeled with [3H]3-Me-His2-TRH. Greatest grain density was found over certain nuclei of the amygdala, with considerable density over several other forebrain areas. Properties of TRH receptor binding in frozen sections closely resembled those of receptors in fresh membrane fragments.