Author Interviews, Infections, OBGYNE, Pediatrics / 14.03.2016
Bacterial Infections in Pregnancy May Lead To Brain Changes in Baby
MedicalResearch.com Interview with:
Elaine Tuomanen, MD
Chair and Full Member
Dept of Infectious Diseases
St Jude Children’s Research Hospital
262 Danny Thomas Place
Memphis, TN 38105
MedicalResearch.com: What is the background for this study? What are the main findings?
Dr. Tuomanen: While investigating mechanisms of brain repair during infection in a mouse model system, we found that components from the surfaces of bacteria could traffic from the mother to the fetus. The bacterial components moved across the placenta and into the fetal brain. To our surprise, the fetal brain did not respond with neuronal death like we see in children with meningitis. Rather, fetal neurons proliferated. This response involved the innate immune system (TLR2) inducing the neuronal transcription factor, FoxG1, which is known to drive proliferation. The newly born neurons migrated appropriately to the cortical plate, the area on the surface of the fetal brain that forms the cortex, a major part of the adult brain. Although the neurons moved to the right place in the brain, there were too many and they crowded together in the cortex, changing the architecture of the brain. At birth, affected mice seemed to have no abnormalities. However, when we tested if this change in architecture would affect brain function after birth, mice were shown to progressively develop defects in learning, memory and other cognitive functions. This indicates there is a window during pregnancy where components of bacteria from the mother can change fetal brain architecture and subsequent postnatal behavior
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