Localization of binding sites for oxytocin in the brain of the golden hamster.

Using a radioiodinated ligand and autoradiography on film, specific binding sites for oxytocin were detected in the brain of the golden hamster. Sites were present in the endopiriform nucleus, the cingulate cortex, the islands of Calleja, the lateral septum, the dorsal hippocampus and the amygdala. The distribution of these binding sites was similar in males and females and was independent of the photoperiod. No binding sites were detected in the ventromedial hypothalamic nucleus or in the dorsal motor nucleus of the vagus nerve; areas which were labelled in the rat and where oxytocin is thought to participate in the control of sexual and autonomic functions. These data suggest that the role of oxytocin in the brain may differ among mammalian species.