Overactive Immune System May Impact Brains of Unborn Male Children

A recent study looks at how immune system "overdrive" can put some pregnant women's male children at risk for certain brain disorders.

According to researchers from the Johns Hopkins University School of Medicine, they found that part of the hippocampus-the brain region primarily responsible for regulating memory and spatial navigation-was typically smaller for male offspring who were exposed in the womb of women who suffered from overactive immune systems. The study also showed that these children had fewer nerve cells located in their brains and could even contain an unnecessary and potentially dangerous brain cell.

"Our research suggests that in mice, males may be more vulnerable to the effects of maternal inflammation than females, and the impact may be life long," said study leader Irina Burd, M.D., Ph.D., an assistant professor of gynecology/obstetrics and neurology at the Johns Hopkins University School of Medicine and director of the Integrated Research Center for Fetal Medicine, via a press release. "Now we wonder if this could explain why more males have diseases such as autism and schizophrenia, which appear to have neurobiological causes."

For the study, researchers studied mice models to try and mimic the effects of a maternal infection and what the causes of inflammation might be for a pregnant mother.

In one group of mice, researchers injected saline solution into the womb. In another group, they injected lipopolysaccharide (LPS), a toxin that generates inflammation similar to the effects of E. coli bacteria.

Shortly following birth, the LPS group demonstrated poor motor skill signs as well as behavior problems, including hyperactivity. Sixty days after birth, or the equivalent to adulthood for mice, these mice still showed signs of hyperactivity and had difficulties walking as well. This suggests that while the motor problems may have been resolved possibly due to brain rewiring, the behavioral ones could not be.

Researchers hope to later zero on the sex-specific differences that play a role in the smaller hippocampus and chronic inflammation. They believe that more information regarding this research could be critical to help develop interventions and potentially new drug therapies.

More information regarding the study can be found via the journal Brain, Behavior and Immunity.