Oxytocin is a well known nonapeptide synthesized in the hypothalamus, acting as neurohormone during parturition and the milk ejection reflex. Animal studies have found that descending pathways for oxytocin synthetizing neurons project to the lamina I-II of the spinal cord, where they activate a subpopulation of glutamatergic and GABAergic interneurons. In addition to GABAergic hyperpolarisation, models of oxytocin selectively blocking A-delta and C-fibers have been published. Intrathecal administration of oxytocin prevents long-term potentiation in the dorsal horn, which is thought to be an important mechanism of enhanced central pain processing.