Quantitative Brain-wide Map of the Oxytocin Receptor in mice during postnatal development

Oxytocin receptor (OTR) plays critical roles in the development of social behavior. Despite its significance, brain-wide quantitative understanding of OTR expression remains limited in postnatally developing brains. Here, we validated and utilized fluorescent reporter mice (OTRvenus/+) to examine OTR positive cells across postnatal periods. We developed postnatal 3D template brains to register cellular resolution whole brain images to systematically quantify OTR cell densities. We found that cortical regions showed temporally and spatially heterogeneous patterns with transient postnatal OTR expression without cell death. Cortical OTR cells were largely not GABAergic neurons with exception in layer 6b. Subcortical regions showed similar temporal regulation except the hypothalamus with sexually dimorphism. Lastly, we created a website to easily share our imaging data as resource. In summary, we established a quantitative mapping method in postnatally developing mouse brains and provide comprehensive data to understand postnatal OTR expression in the mouse brain.