The Plastic and Functional Changes in Hippocampal Neurons During Pregnancy, Delivery, and Postpartum Are Reversed by Offspring Deprivation

The study aimed to evaluate the changes in neurotrophic factors, synaptic plasticity, and neurogenesis in the hippocampus of rats during pregnancy, lactation, and after being deprived of their pups. The study found that Brain-Derived Neurotrophic Factor (BDNF), Activity-regulated Cytoskeletal (Arc) protein expression, and dendritic spine density (DSD) significantly increased after 21 days of pregnancy and lasted for 21 days during lactation. These changes were associated with a dramatic reduction of neurosteroid content. However, these effects were abolished by physiological weaning (21 days after delivery). An increase in cell proliferation was observed after 21 days of pregnancy, but decreased during the first three weeks of postpartum. The drugs Finasteride and Clomiphene did not modify these changes. Deprivation of pups induced a rapid reduction in BDNF, Arc, and DSD while increasing cell proliferation. The study concluded that these changes in the plastic properties of hippocampal neurons may play a crucial role in the modulation of maternal care in rats.