Oxytocin (OXT), a neuropeptide synthesized in the hypothalamic paraventricular (PVN) and supraoptic nuclei (SON), is traditionally known for its roles in parturition and lactation. However, accumulating evidence indicates that OXT also functions as an endogenous analgesic modulator acting through central and peripheral pathways. In this review, we summarize recent advances in the understanding the role of OXT for pain modulation, focusing on descending hypothalamo-spinal projections, peripheral neuroendocrine mechanisms, and novel experimental approaches using transgenic and chemogenetic rat models. We also discuss new findings on the OXT-mediated analgesic effects of the traditional Kampo medicine Kamikihi-to and chemogenetic activation of OXT neurons in fibromyalgia models. Together, these studies establish OXT as a multi-level modulator of nociception, bridging neuroendocrinology and pain research.
Maruyama et al. (Fri,) studied this question.