Paternal Deprivation Alters Neural Stem Cells Proliferation and Epigenetic Histone Modifications in the Neurogenic Niches of Adult Prairie Voles

Paternal deprivation has behavioral, neurochemical, and neuroendocrine consequences in adulthood. Socially monogamous prairie voles (<i>Microtus ochrogaster</i>) raised only by the mother (monoparental care, MP) showed low levels of alloparental behavior and delayed pair bonding formation in adulthood compared to those raised by both parents (biparental care, BP). However, the effects of paternal deprivation on adult neurogenesis and the epigenetic mechanisms involved remain to be elucidated. Here, we focused on the impact of MP rearing on neural stem cells (NSCs) proliferation under basal conditions and in response to cohabitation with the sexual partner during pair bonding formation. At basal conditions, we found a significant decrease in the number of new proliferative NSCs (BrdU⁺/SOX2⁺) in male and female MP voles compared to BP animals in the subventricular (SVZ) and subgranular zone (SGZ). After 24 h of cohabitation, in MP males, there was an increase in the number of newborn cells in the SVZ but not in the SGZ. However, this increased proliferation was lower than in BP males. In females, we did not observe significant differences compared to controls. Finally, we evaluated the enrichment of H3K4me3 (activation) and H3K27me3 (silencing) epigenetic marks in the new cells, finding differences between rearing systems and sexes.