💊Oxytocin
Nonapeptide governing social bonding, trust, pair bonding, arousal, and reproductive function. Primary research tool for social neuroscience, ASD, PTSD, and attachment biology.
Cys-Tyr-Ile-Gln-Asn-Cys-Pro-Leu-Gly-NH₂What Is Oxytocin?
Oxytocin is synthesised in the hypothalamic PVN and SON, released both peripherally (posterior pituitary) and centrally (axonal projections). One of the most evolutionarily conserved peptides in vertebrate neuroscience, with roles spanning uterine contraction (peripheral) to social bonding, trust, and sexual reward (central).
Key Mechanisms
- OTR / Gq / PLC / IP3 — primary intracellular cascade: Ca²⁺ release and PKC activation
- Mesolimbic dopamine — OTR in NAc potentiates D2 signalling; basis of social reward
- Amygdala CRF suppression — PVN→CeA projections reduce fear conditioning and anxiety
- Serotonin cross-talk — bidirectional 5-HT feedback in dorsal raphe
Key References
- Kosfeld M et al. "Oxytocin increases trust in humans." Nature, 2005;435:673–676.
- Insel TR, Young LJ. "The neurobiology of attachment." Nat Rev Neurosci, 2001;2:129–136.
Frequently Asked Questions
Peripheral (IV/SC) oxytocin has limited BBB penetration, which is part of why intranasal delivery routes are frequently used in social-neuroscience research aiming for central effects — the two routes aren't pharmacokinetically equivalent.
No — it also has well-characterised peripheral roles (uterine contraction, milk ejection) and central roles beyond bonding, including anxiety/fear circuit modulation via amygdala CRF suppression, which is why it's studied across reproductive, psychiatric, and social-neuroscience domains.
It should be kept refrigerated and used within a limited window after reconstitution — oxytocin is comparatively prone to degradation in solution, so many protocols prepare fresh working solutions rather than storing long-term.