Maternal infection disrupts newborn brain development: Study

A team of European researchers has in a pioneering study, released on Tuesday, found compelling evidence that maternal infections during pregnancy can have lasting effects on offspring brain function.

The findings, published in the peer-reviewed journal Brain Medicine, may have implications for neurodevelopmental and psychiatric disorders like autism, schizophrenia, and depression.

The team from the Slovak Academy of Sciences in Slovakia investigated the impact of maternal immune activation (MIA) on hippocampal pyramidal neurons in newborn rat offspring.

The hippocampus is a crucial brain region involved in memory, emotion, and cognition. They found that prenatal inflammation significantly impairs neuronal excitability, which increases the risk of neurodevelopmental disorders associated with maternal infections.

“Maternal infections are a known risk factor for conditions like autism, schizophrenia, and depression,” said Dr. Eliyahu Dremencov, from the institute.

“Our research shows that early-life alterations in hippocampal neuron function could be a key mechanism linking prenatal inflammation to these disorders,” Dremencov added.

During pregnancy, infections trigger an immune response that releases cytokines -- chemical messengers that can cross the placenta and impact foetal brain development.

Using a well-established animal model, the researchers induced MIA in pregnant rats with lipopolysaccharide (LPS) -- a bacterial component that stimulates the immune system. The hippocampal neurons of newborn offspring were then assessed to see how prenatal immune activation affected their excitability.

“We observed that neurons from MIA-exposed offspring had a significantly higher threshold for activation, slower response times, and reduced firing rates,” explained lead author Dr. Lucia Moravcikova, of the study.

“This suggests a disruption in glutamatergic neurotransmission, which plays a critical role in learning, memory, and emotional regulation,” Moravcikova added.

Further, the team found major changes in hippocampal neuron function in newborns exposed to MIA.

They found that the neurons required a stronger stimulus to activate, suggesting impaired excitability; the neurons also took longer to respond to stimulation, affecting signal transmission.

Notably, male offspring showed a greater reduction in spontaneous neuronal activity, which may explain why conditions like autism and schizophrenia are more commonly diagnosed in males.