According to a study out of the Weizmann Institute of Science and published in the journal Science, new research findings in mice may help explain how viral infection during pregnancy raises the risk of autism and schizophrenia in their offspring. The study may explain, among other things, how the mother’s infection with the cytomegalovirus (CMV) during pregnancy, which affects her own and her fetus’s immune system, increases the risk that her offspring will develop autism or schizophrenia, sometimes even years later.
“Previous studies had shown that the timing of the disruption in the mother’s immune system during pregnancy affects the type of brain damage her child may develop. For example, a viral infection in early pregnancy raises the risk of autism, whereas an infection later in pregnancy raises the risk of schizophrenia,” said one researcher. “We’ve set out to examine the mechanisms behind these phenomena, while focusing on the role the immune system plays in brain development.”
One researcher focused on the microglia, which contributes to the brain’s development and maintenance. They discovered that the development of these cells in the mouse fetus and in newborn mice proceeds in three distinct stages, parallel to those of the developing brain. The second of these three stages appeared to be the most sensitive to disruptions. This stage takes place close to birth and shortly afterward. During this time, the pre-microglia play an important role in pruning, helping remove the superfluous neuronal networks, and shaping and strengthening the connections among the remaining neurons.
When the scientists exposed the brains of pregnant mice to synthetic materials that mimic a CMV infection, they found that the development of the pre-microglia was disrupted. These offspring later exhibited abnormal behavior, including disturbances in social interaction and behaviors similar to those of people with schizophrenia.
“We’ve discovered that it’s essential for the development of immune cells in the brain to be synchronized with the development of the brain itself,” said one researcher. “Premature shift of the microglia in mice to the adult stage leads to brain malfunction later on.”
They note that “Our research has paved the way for studying the effects of other viruses on the mother’s immune system in general, and on her offspring’s brain development. It can also advance the study of neurodevelopmental disorders and their connection to the immune system.”
Razi Berry, Founder and Publisher of Naturopathic Doctor News & Review (ndnr.com) and NaturalPath (thenatpath.com), has spent the last decade as a natural medicine advocate and marketing whiz. She has galvanized and supported the naturopathic community, bringing a higher quality of healthcare to millions of North Americans through her publications. A self-proclaimed health-food junkie and mother of two; she loves all things nature, is obsessed with organic gardening, growing fruit trees (not easy in Phoenix), laughing until she snorts, and homeschooling. She is a little bit crunchy and yes, that is her real name.
