of OXTR (coupling to Gq or Gi/Go) most likely results in opposite effects on cell excitability (Gravati et al., 2010). One possible hypothesis is that the local concentration reached by OXT may engage different signaling pathways to allow for more finely tuned signaling mechanisms and behavioral responses (Grinevich et al., 2016). Further, due to high structural homology OXT can also bind to and activate the related vasopressin receptor subtypes (V1a, V1b and V2) (Knobloch and Grinevich, 2014). Under some conditions, this may constitute alternative targets for OXT, especially at pharmacological concentrations and in brain regions that have little or no OXTR expression (Grinevich et al., 2016).
