BRATISLAVA, Slovakia, 18 March 2025 – A pioneering peer-reviewed research study published in Brain Medicine provides compelling evidence that maternal infections during pregnancy can have lasting effects on offspring brain function. Researchers from the Slovak Academy of Sciences investigated the impact of maternal immune activation (MIA) on hippocampal pyramidal neurons in newborn rat offspring and found that prenatal inflammation significantly impairs neuronal excitability. These changes in brain function may underlie the increased 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, corresponding author of the study. "Our research shows that early-life alterations in hippocampal neuron function could be a key mechanism linking prenatal inflammation to these disorders."
How Maternal Inflammation Impacts Brain Development
During pregnancy, infections trigger an immune response that releases cytokines—chemical messengers that can cross the placenta and impact fetal 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. They then examined the hippocampal neurons of newborn offspring to assess 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 Dr. Lucia Moravcikova, lead author of the study. "This suggests a disruption in glutamatergic neurotransmission, which plays a critical role in learning, memory, and emotional regulation."
Key Findings: Altered Neuronal Excitability and Reduced Firing Rates
The study's electrophysiological analysis revealed several major changes in hippocampal neuron function in newborns exposed to MIA:
- Increased threshold potential – Neurons required a stronger stimulus to activate, suggesting impaired excitability.
- Delayed action potential latency – Neurons took longer to respond to stimulation, affecting signal transmission.
- Reduced peak potential and firing rates – Both spontaneous and evoked activity were significantly decreased, indicating lower neurotransmitter release.
- Sex-specific effects – Male offspring showed a greater reduction in spontaneous neuronal activity, which may have implications for the higher prevalence of certain neurodevelopmental disorders in males.
"One of the most striking aspects of our findings is the sex-specific vulnerability to prenatal inflammation," noted Dr. Moravcikova. "This could help explain why conditions like autism and schizophrenia are more commonly diagnosed in males."
Implications for Autism, Schizophrenia, and Depression
The hippocampus is a crucial brain region involved in memory, emotion, and cognition, and its dysfunction has been implicated in multiple neurodevelopmental disorders. The study's results support the hypothesis that prenatal immune challenges can disrupt early brain wiring, leading to long-term cognitive and behavioral impairments.
"Our findings align with human epidemiological studies linking maternal infection to an increased risk of psychiatric disorders," said Dr. Dremencov. "Understanding how prenatal inflammation alters brain function could open the door to new preventative or therapeutic approaches."
Potential Therapeutic Interventions
With growing evidence that prenatal inflammation affects brain function, researchers are now exploring strategies to mitigate these effects. Potential interventions include:
- Anti-inflammatory treatments during pregnancy – Carefully administered medications that reduce excessive immune responses.
- Neuroprotective therapies – Targeting disrupted neurotransmitter pathways to restore normal brain function.
- Early-life interventions – Techniques like transcranial magnetic stimulation (TMS) to enhance neuronal excitability and connectivity.
"If we can identify ways to prevent or reverse these changes in early development, we may be able to reduce the long-term burden of neurodevelopmental disorders," said Dr. Dremencov.
Key Questions Moving Forward
- Can prenatal anti-inflammatory treatments reduce the risk of neurodevelopmental disorders?
- How do these findings translate to human brain development?
- Are there specific time windows during pregnancy when interventions would be most effective?
The peer-reviewed Research Article "Maternal immune activation impairs hippocampal pyramidal neuron excitability in newborn rat offspring: Implications for neurodevelopmental disorders" appears online on 18 March 2025 in Brain Medicine (Genomic Press) and is freely accessible at https://doi.org/10.61373/bm025a.0029 .
About Brain Medicine: Brain Medicine (ISSN: 2997-2639) is a high-quality medical research journal published by Genomic Press, New York. Brain Medicine is a new home for the cross-disciplinary pathway from innovation in fundamental neuroscience to translational initiatives in brain medicine. The journal's scope includes the underlying science, causes, outcomes, treatments, and societal impact of brain disorders across all clinical disciplines and their interface.
