Lipopolysaccharide injected to pregnant mice affects behavior of their offspring in adulthood.

We studied consequences of maternal immune response on the course of pregnancy and the behavior of adult offspring. Mice in late gestation (day 16-17) were injected with lipopolysaccharide (LPS). Treatment of pregnant mice with high doses of LPS resulted in fetal resorption or stillbirths. Pregnant mice treated with low doses (100 or 300 micrograms/kg) of LPS gave birth to normal numbers of pups. However, behavior of the offspring was altered. Adult offspring of dams injected at a dose of 300 micrograms/kg of LPS traveled longer distances in the open field and spent more time in the central part of the arena, than mice in the control group. Female mice of this group spent more time in open arms of the elevated plus maze, in comparison to female control mice. Results of the Morris water maze test showed impairment of spatial learning and memory in male offspring born to LPS-injected dams. Furthermore, in the nest building test adult mice born from LPS challenged pregnancies constructed worse quality nests, which points to the presence of hippocampal dysfunction. These findings indicate that maternal bacterial infections during pregnancy may alter offspring behavior in adult life.