Offspring exposed to an overactive maternal immune system during pregnancy — either from an infection or another illness — exhibit lasting signs of brain damage into adulthood, says a new study published in the journal Brain, Behavior, and Immunity.
Previous research has indicated that inflammation between 18 and 32 weeks of gestation in humans as the result of overactivity in the maternal immune system is linked to premature birth, an imbalance of immune cells in the brains of offspring, and even nerve cell death in the brains of offspring.
For the present study, researchers from Johns Hopkins Medicine in Baltimore, Maryland used a rodent model to investigate the effects of prenatal intrauterine infection or inflammation on the brains of offspring. Using two groups of mice, the researchers injected saline injections into the womb of one group and lipopolysaccharide (LPS) injections into the womb of the second group. LPS is a toxin meant to generate the kind of inflammatory effects of E. coli bacteria.
The male offspring exposed to LPS in the womb had smaller hippocampuses, the part of the brain responsible for memory and spatial navigation, over the long term. The expose mice also had fewer nerve cells in the brain. Additionally, the brains of the exposed mice contained a type of immune cell not normally present.
The differences between the two groups of mice persisted into adulthood.
Comments 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:
“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. Now we wonder if this could explain why more males have diseases such as autism and schizophrenia, which appear to have neurobiological causes.”
Based on the present findings, the researchers believe that chronic inflammation inhibits brain development, thus keeping the hippocampus small.
The researchers also believe that the findings could be relevant to neurologic diseases such as schizophrenia and autism in humans.
Additional research is still needed to investigate the sex differences in response to inflammation in the womb. Males tend to fair worse than females.
The results of this study may help develop interventions and new drug therapies to treat the inflamation associated with an overactive maternal immune system during pregnancy and may provide the knowledge that helps solve the problem of neurologic diseases such as schizophrenia and autism.
Immune System ‘Overdrive’ in Pregnant Women Puts Male Offpsring at Special Risk for Adult Brain Disorders, Mouse Study Suggest: http://www.hopkinsmedicine.org/news/media/releases/immune_system_overdrive_in_pregnant_women_puts_male_offspring_at_special_risk_for_adult_brain_disorders_mouse_study_suggests_
Mouse Model of Intrauterine Inflammation: Sex-specific Differences in Long-term Neurologic and Immune Sequelae: http://www.sciencedirect.com/science/article/pii/S0889159114000154
Pregnancy: Overactive Immune System Linked to Offspring Brain Damage: http://www.medicalnewstoday.com/articles/272372.php
Overactive Immune System Linked to Offspring Brain Damage: http://www.sxc.hu/photo/844705