A team of researchers has revealed that fetal mice- especially males- show signs of brain damage that lasts into their adulthood when they are exposed in the womb to a maternal immune system kicked into high gear by a serious infection or other malady.

The findings suggest that some neurologic diseases in humans could be similarly rooted in prenatal exposure to inflammatory immune responses.

The investigators said that the part of the brain responsible for memory and spatial navigation (the hippocampus) was smaller over the long term in the male offspring exposed to the overactive immune system in the womb.

The males also had fewer nerve cells in their brains and their brains contained a type of immune cell that shouldn't be present there.

"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," study leader Irina Burd, M.D., Ph.D., an assistant professor of gynecology/obstetrics and neurology at the Johns Hopkins University School of Medicine, said.

"Now we wonder if this could explain why more males have diseases such as autism and schizophrenia, which appear to have neurobiological causes," the researcher said.

For the study, researchers sought to mimic the effects of a maternal infection or other condition that causes inflammation in a pregnant mother.

Burd and her colleagues used a mouse model to study what happens to the brains of those offspring as they age into adulthood to see if the effects persisted.

Chronic inflammation, Burd said, may play a role in keeping the hippocampus small, potentially because it inhibits proper brain development. But why males and females respond differently to the same insult in utero remains a question.

The study was published in the journal Brain, Behavior and Immunity.