bulk RNAseq from the medial amygdala of male and female mice
Sexual dimorphism in the brain is well-documented, yet clear binary features akin to genital differences remain elusive. Using the TRAP2 transgenic mouse line to track cFos-driven neuronal activity, we identified a distinct cluster of neurons (~200?µm) in the posterodorsal medial amygdala—termed the DIMPLE—that exhibited binary activation: consistently labeled in females but absent in adult virgin males. This pattern was unaffected by gonadectomy but was present in juvenile males before weaning and re-emerged in adult males after mating. Public RNA-seq data showed prolactin receptor enrichment in this region, and exogenous prolactin administration activated DIMPLE in virgin males. We propose that DIMPLE may support neural mechanisms related to female-typical behavior or paternal readiness. Overall design: Medial amygdala (MeA) tissue containing the DIMPLE—comprising approximately 18–40% of the extracted area—was collected from TRAP2-Ai9 mice, including 3 adult females and 4 adult males that were labeled with tamoxifen at postnatal day 24 (P24).