Figure 6. Effects of Reproductive State and Acute Antenatal Immune Activation on Inflammatory Gene Expression in the Medial Prefrontal Cortex and Hippocampus Immediately Postpartum.

Between Embryonic (E) day 21 and 22, rats received an injection of either lipopolysaccharide (LPS) (100μg/kg) or its saline vehicle at equal volume. Animals were euthanized on day of birth (P0) or at least 24 hours after the injection for non-pregnant animals. A. In the mPFC, analysis of CD11b expression revealed an interaction of pregnancy and immune activation. Post hoc analysis indicated the Postpartum, LPS-treated group had significantly lower expression than the Non-pregnant, LPS-treated group. B. IL-1β analysis revealed a significant interaction of pregnancy and immune activation. Post hoc analysis revealed trends that the Pregnant, LPS-treated group had lower expression than the Non-pregnant, LPS-treated and Postpartum, Saline-treated groups (p < 0.08). C. Analysis of IL-6 showed a significant main effect of pregnancy and an interaction of pregnancy and immune activation such that the Postpartum, Saline-treated animals and the Non-pregnant, LPS-treated animals had significantly higher expression compared to Non-pregnant, Saline-treated controls. D, E. IL-4 and BDNF analysis revealed a significant main effect of reproductive state in that only postpartum females showed higher gene expression relative to non-pregnant rats. F. In the HP, analysis of IL-1β showed a main effect of treatment. Only the Non-pregnant, LPS-treated group showed significantly higher gene expression compared to the other three groups (p < 0.05). G, H. IL-6 and IL-4 showed a main effect of pregnancy such that postpartum rats showed higher gene expression relative to the non-pregnant groups. No significant differences were found for CD11b or BDNF in the HP (not shown). *: p < 0.05; **: p < 0.001, #: p < 0.08