Possible brain regions involved in parturition in mice

Parturition is a vital physiological process in the reproduction of female mammals, regulated by neurohumoral mechanisms coordinated by the central nervous system. The uterus is essential for this process; however, the neural pathways connecting the brain to the uterus remain poorly understood. In this study, we combined the pseudorabies virus (PRV) tracing tool with c-Fos immunofluorescence staining to identify brain regions that may regulate uterine muscle activity during parturition. We observed that the paraventricular nucleus (PVN), periaqueductal gray (PAG), and locus coeruleus (LC) were colabeled with PRV and c-Fos. Subsequently, we focused on the PVN to determine whether its activity correlated with parturition behavior. We used fiber photometry to record Ca²⁺ activity in the PVN during parturition in freely behaving mice and found a strong correlation between PVN activity and parturition behavior. Our results demonstrate that this method is both accessible and reliable for studying the roles of central-peripheral neural pathways involved in parturition behavior and suggest that PVN may be a key brain node for parturition.NEW & NOTEWORTHY Parturition is a vital physiological process in the reproduction of female mammals. Here, the authors established a method that combined retrograde tracing, c-Fos immunofluorescence staining, and fiber photometry to study the roles of central-peripheral neural pathways involved in parturition. Our method is simple and reliable to investigate the roles of central-peripheral neural pathways involved in a range of physiological processes in freely moving animals.