Sniffing oxytocin: Nose to brain or nose to blood?

This study investigated the routes by which intranasally administered oxytocin (OXT) exerts its effects on the brain and behavior. Using vasoconstrictor pretreatment to prevent OXT from entering the peripheral circulation, the researchers measured effects on resting-state neural activity (EEG) and physiological responses. Results showed that intranasal OXT alone increased delta-beta cross-frequency coupling (CFC), an effect largely abolished by vasoconstrictor pretreatment. Positive correlations were found between plasma OXT concentrations and increases in delta-beta CFC, suggesting a critical role of peripheral vasculature-mediated routes on the neural effects of exogenous OXT administration.

Shuxia Yao, Yuanshu Chen, Qian Zhuang, Yingying Zhang, Chunnie Lan, Siyu Zhu, Benjamin Becker, Keith M. Kendrick