Cells from your mother likely infiltrated your brain in the womb, and they could survive for decades, study reveals - Live Science

What the report says

Live Science reported that a new study posted June 10 to the preprint server bioRxiv found evidence that cells carrying a mother’s DNA can be present in her children’s brain tissue and may remain there for decades. The work focuses on microchimerism, the exchange and long-term persistence of cells between mother and fetus during pregnancy. The study has not yet been peer reviewed.

According to Live Science, a team led by Sami Kanaan of Fred Hutchinson Cancer Center analyzed brain tissue surgically removed from 37 children with severe epilepsy, ranging in age from 28 days to 19 years, and compared it with DNA samples provided by their mothers. Using quantitative PCR, the researchers detected maternal cells in 26 of the 37 children, or about 70%. These cells appeared in several brain regions, including parts of the outer brain and the hippocampus, though the amount varied widely and some samples showed no maternal DNA.

The researchers also used single-nucleus RNA sequencing to examine what roles the maternal cells seemed to be performing. Live Science reported that the cells had features of multiple brain cell types, including neurons, astrocytes, oligodendrocytes, microglia and endothelial cells. In a separate analysis of autopsy brain data from people without known neurodevelopmental conditions, foreign cells were found in 25 of 32 individuals, including one man in his 90s, though maternal origin could not be confirmed without mothers’ DNA.

Experts not involved in the study told Live Science the findings add to evidence that microchimerism is a common biological process and may have significance for brain development or function. They also cautioned that larger, more consistent datasets will be needed to understand what these cells do and whether they affect health.