Prenatal Inflammation Dampens Neurogenesis and Enhances Serotonin Transporter Expression in the Hippocampus of Adult Female Rats

Abstract

Background/Aims: Prenatal exposure to lipopolysaccharide (LPS) dampens hippocampal neurogenesis. This effect is associated with increased anxiety-like behavior in adult offspring. Furthermore, blocking serotonin transporters (SERT) promotes adult neurogenesis. Previous studies were performed largely in males. Therefore, we explored the impact of prenatal LPS on neurogenesis, SERT expression in the hippocampus, and anxiety-like behavior in female rats during prepubertal and adulthood stages. Materials and Methods: Timed pregnant rats were injected with either saline or LPS (100 µg/kg, i.p.) on gestational days 15, 17, and 19. Newly born neurons were monitored by immunohistochemistry, and anxiety-like behavior was monitored using the elevated plus maze and open-field test. SERT expression in the hippocampus was assessed by Western blot and immunofluorescence. Results: Prenatal LPS led to reduced hippocampal neurogenesis in adult but not in prepubertal female offspring. This reduced neurogenesis was associated with enhanced hippocampal expression of SERT protein. However, there was no significant impact of prenatal LPS on anxiety-like behavior. Conclusions: Prenatal LPS-induced reduction in neurogenesis was dissociated from anxiety-like behavior in adult female rats. Furthermore, the long-lasting impact of prenatal LPS on neurogenesis in female offspring was age-dependent.