Brain areas affected by intranasal oxytocin show higher oxytocin receptor expression

Neuroimaging studies suggest that intranasal oxytocin (IN‐OXT) may modulate emotional and social processes by altering neural activity patterns. The extent of brain penetration after IN‐OXT is unclear, and it is currently unknown whether IN‐OXT can directly bind central oxytocin receptors (OXTRs). We investigated oxytocin pathway gene expression in regions affected by IN‐OXT on task‐based fMRI. We found that OXTR is more highly expressed in affected than unaffected subcortical regions; this effect did not vary by task type or sex. Cortical results revealed higher OXTR expression in regions affected by IN‐OXT in emotional processing tasks and in male‐only data. No significant differences were found in expression of the closely related vasopressin receptors. Our findings suggest that the mechanism by which IN‐OXT may alter brain functionality involves direct activation of central OXTRs.