Immunohistochemical research on oxytocin in the hypothalamic accessory nuclei.

Immunohistochemical research on the monoclonal antibody, anti-oxytocin, was carried out on hypothalamic accessory nuclei. The nuclei and the accessory neurons were strongly positive in much the same way as the supraoptic and paraventricular nuclei. These results indicate that the accessory nuclei are able to synthesize the neurohormone oxytocin. Based on the present research and on preceding papers, it is possible to affirm that the accessory nuclei synthesize both oxytocin and vasopressin. Therefore the accessory nuclei must be considered an integral part of the magnocellular hypothalamic neurosecretory system.