DNA from male babies can enter the mother’s brain. And it remains there for decades. The baby’s DNA becomes a part of the mother’s brain. The foetal cells carry the DNA inside the mother’s brain. Theses foetal cells travel through the placenta to the mother’s body. This phenomenon is called as foetal microchimerism. Microchimerism means presence of genetically different cells in the body of an individual.
Female’s DNA is harder to distinguish in a mother as both the mother and the female foetus carry two X chromosomes each. While as in, it is easy to detect a male foetus’s Y chromosome in the mother’s brain. The scientists detected male DNA by searching for Y chromosome.
The brain is protected from drugs and various organisms by a layer known as blood brain barrier. Blood brain barrier is a layer which is selectively permeable that is it allows very few substances to travel across it and gain entry into the brain. During pregnancy the permeability of this layer increases. Hence, cells from the baby can enter the brain of the mother. Scientists found that women with Alzheimer’s disease are less likely to have the male DNA in their brains. This suggests that the baby DNA in mother’s brain could be beneficial for the mother.
Researchers hope to confirm whether the presence of baby’s DNA is good or bad for the mother’s brain and its usefulness in future treatment of Alzheimer’s disease.