Abstract
Oxytocin-mediated milk ejection (ME) is pivotal to effective breastfeeding and reproductive health, yet behaviorally decoding and revealing neural mechanisms of ME remains challenging. Here, we combined in vivo calcium imaging and intramammary pressure recording to uncover the temporal connections between episodic activity of oxytocin neurons and ME in conscious lactating rats. Leveraging the coordinated behavioral responses of dams and pups, we developed a supervised machine learning framework (ME Decoder) to enable automated analyses of ME. Inspired by its interpretable features, we defined the activity-coupled dam-pup interactions (ADPI), manifested by pronounced kyphosis in dams, followed by pup treading and stretching, as the behavioral signatures of ME. By ME Decoder and ADPI analyses, we detected reduced ME but unaffected activity of oxytocinergic neurons after systemic blockade of oxytocin receptors. Our study uncovers the oxytocinergic and behavioral signatures of ME and provides a generalizable approach for further investigation.