Autoradiographic Localization of Radioactivity in the Rat Brain After the Injection of 1,2-3H-Testosterone

Abstract

The localization of radioactivity in the brain of immature intact and mature castrated Sprague—Dawley rats was investigated by drymount autoradiography at 1 hr after the injection of l,2–³H-testosterone. Radioactivity is found to be selectively concentrated and retained in specific neurons in the nucleus (n.) arcuatus and the n. ventromedialis hypothalami, the n. preopticus medialis, the n. interstitialis striae terminalis, the n. septi lateralis, the hippocampus and the amygdala. The topographic distribution of androgenconcentrating neurons agrees well with areas in the brain that have been associated with the regulation of gonadotropin secretion and male sex behavior. The autoradiographic data are consistent with the hypothesis that androgen feedback occurs at hypothalamic and extrahypothalamic sites in the central nervous system. (Endocrinology92: 251, 1973)