Hippocampal 3α,5α-THP May Alter Depressive Behavior of Pregnant and Lactating Rats

This study explored the role of 3α,5α-THP, a metabolite of progesterone, in influencing depressive behavior in pregnant and lactating rats. It was found that higher levels of 3α,5α-THP in the hippocampus were associated with reduced depressive behavior, as observed in pregnant rats compared to postpartum rats. The administration of finasteride, which inhibits the conversion of progesterone to 3α,5α-THP, resulted in increased depressive behavior, supporting the hypothesis that 3α,5α-THP plays a significant role in mood regulation. Additionally, the study examined the effects of prenatal stress (PNS) on depressive behavior and found that PNS rats exhibited altered responses to hormonal changes, potentially due to lower hippocampal 3α,5α-THP levels. These findings suggested that 3α,5α-THP might mitigate depressive symptoms by modulating the hypothalamic-pituitary-adrenal (HPA) axis and promoting neurogenesis in the hippocampus.