Lactation showcases the dynamic interplay between neural synchronization and hormonal regulation, crucial for mammalian offspring nourishment. Central to this process is oxytocin (OT), whose release, driven by the synchronized activity of magnocellular OT neurons, facilitates milk let-down. Despite its significance, the underlying neural mechanisms remain to be fully elucidated. Our study advances this understanding by exploring the role of parvocellular OT neurons, previously identified as key modulators of magnocellular neuron activity. Employing advanced opto- and pharmacogenetic techniques, alongside in vivo recordings and behavioral analyses, we investigate these neurons' contributions to lactation in rats. We discovered anisotropic synchronization of OT neurons within key brain regions (the paraventricular and supraoptic nuclei) during lactation, characterized by distinct synchronization patterns in response to suckling. Our experiments established a causal relationship between parvocellular OT neuron activity and magnocellular OT neuron bursting, essential for effective lactation. Activation of parvocellular neurons compensated for lactation deficits caused by sensory deprivation, demonstrating their critical role in this biological process. Furthermore, using a novel OT sensor, we showed that neuronal bursting leads to substantial OT release, highlighting the tight link between neural activity and hormone secretion. These findings reveal new insights into the OT network dynamics governing lactation, emphasizing the importance of neural synchronization and plasticity in regulating physiological states. This study contributes significantly to our understanding of the complex mechanisms that facilitate mammalian parenting behaviors.