Oxytocin

What Is Oxytocin?

Oxytocin is a nine-amino-acid neuropeptide synthesised in the hypothalamus and released by the posterior pituitary. It acts on the oxytocin receptor (OXTR), a G-protein-coupled receptor densely expressed in the amygdala, nucleus accumbens, and prefrontal cortex, and in peripheral tissues including the uterus, mammary gland, and cardiovascular system.

Centrally, OXTR activation modulates social behaviour in three documented ways: it dampens amygdala threat response, increases ventral striatum reward signalling in response to social cues, and enhances theory-of-mind processing (recognition of social and emotional cues in others). Peripherally, oxytocin drives uterine contraction in labour and milk ejection in lactation, its approved clinical uses. Research interest centres on the central effects, with trials in social anxiety, autism spectrum conditions, and couples-therapy adjuncts. Systemic half-life is a few minutes, and oxytocin crosses the blood-brain barrier poorly from circulation, which is why the intranasal route dominates the research literature: it reaches the brain via the cribriform plate.