Pubertal maternal presence reduces anxiety and increases adult neurogenesis in Kunming mice offspring

Puberty is a critical period of emotional development and neuroplasticity. However, most studies have focused on early development, with limited research on puberty, particularly the parental presence. In this study, four groups were established, and pubertal maternal presence (PMP) was assessed until postnatal days 21 (PD21), 28 (PD28), 35 (PD35), and 42 (PD42), respectively. The social interaction and anxiety behaviors, as well as the expression of oxytocin (OT) in the paraventricular nucleus (PVN) and supraoptic nucleus (SON), and the number of new generated neurons and the expression of estrogen receptor alpha (ERα) in the dentate gyrus (DG) were assessed. The results suggest that there is a lot of physical contact between the mother and offspring from 21 to 42 days of age, which reduces anxiety in both female and male offspring in adulthood; for example, the PMP increased the amount of time mice spent in the center area in the open field experiment and in the bright area in the light-dark box experiment. PMP increased OT expression in the PVN and SON and the number of newly generated neurons in the DG. However, there was a sexual difference in ERα, with ERα increasing in females but decreasing in males. In conclusion, PMP reduces the anxiety of offspring in adulthood, increases OT in the PVN and SON, and adult neurogenesis; ERα in the DG may be involved in this process.