Neonatal inflammatory pain increases hippocampal neurogenesis in rat pups

► An animal model was used to investigate how an early painful experience affects the generation of new neurons in the dentate gyrus region of the hippocampus. ► Compared to control animals, rat pups injected with the painful inflammatory agent complete Freund's adjuvant (CFA) on postnatal day 8 showed an increase in dentate gyrus neurogenesis, evidenced by a greater number of BrdU+ cells and a higher density of doublecortin+ cells in the subgranular zone. ► The increase in dentate gyrus neurogenesis following CFA injection suggests that early painful experiences may shape hippocampal development and thereby influence behavioral outcome.