Plasticity of Oxytocin Receptors in the Postpartum Period Using a Hamster Model

Abstract

The deleterious consequences of postpartum depression and anxiety (PPD) on the mother-child dyad has greatly incentivized more research in the neurobiological mechanisms during the peripartum period. Several studies have stipulated that neurobiological and hormonal components may lead to the etiology of PPD. However, a greater understanding of the complexities of PPD will not unfold until knowledge on the typical patterns of puerperium is prioritized. In the current study, we simulated pregnancy in a hamster model to investigate changes in oxytocin receptor density in the efferents of the paraventricular nucleus (PVN). For the four regions of interest, we predicted a decrease in oxytocin receptors density for the estrogen-withdrawn hamsters within the postpartum period. The raphe nucleus (RN) was the only region of interest that attained statistical significance. Contrary to our hypothesis, the estrogen-withdrawn group exhibited a significant increase of oxytocin receptors compared to the control group in this region. Utilizing an open field test and elevated plus maze, we also expected to observe less anxiety-like behaviors from the estrogen-withdrawn group. However, our results did not reveal any statistical significance for anxiety-like behaviors. Following previous results, this study also investigated the overall neurodegeneration within the PVN, specifically an increase of cell-death in the estrogen-sustained group. After qualitative analysis, we visualized greater fluoro-jade staining, a measure of neurodegeneration, within the estrogen-withdrawn group. By gaining greater comprehension of the estrogen and oxytocin pathway, it will lead to a greater understanding of the typical postpartum period and, thereby, the intricacies involved in the peripartum period.