Interplay between the oxytocin and opioid systems in regulating social behaviour

The influence of neuromodulators on brain activity and behaviour is undeniably profound, yet our knowledge of the underlying mechanisms, or ability to reliably reproduce effects across varying conditions, is still lacking. Oxytocin, a hormone that acts as a neuromodulator in the brain, is an example of this quandary; it powerfully shapes behaviours across nearly all mammalian species, yet when manipulated exogenously can produce unreliable or sometimes unexpected behavioural results across varying contexts. While current research is rapidly expanding our understanding of oxytocin, interactions between oxytocin and other neuromodulatory systems remain underappreciated in the current literature. This review highlights interactions between oxytocin and the opioid system that serve to influence social behaviour and proposes a parallel-mechanism hypothesis to explain the supralinear effects of combinatorial neuropharmacological approaches.This article is part of the theme issue 'Interplays between oxytocin and other neuromodulators in shaping complex social behaviours'.

Automated summary

The influence of neuromodulators on brain activity and behavior is significant, but our understanding of the mechanisms and ability to reproduce effects is still lacking. Oxytocin, a neuromodulator in the brain, has powerful effects on behavior but can produce unreliable or unexpected results when manipulated. Current research is expanding our understanding of oxytocin, but interactions with other neuromodulatory systems are underappreciated in the literature.