Our (adopted) children's cells live on in our brains

 "Maternite" by Mary Cassatt

"The profound psychological and physical bonds shared by the mother and her child begin during gestation when the mother is everything for the developing fetus, supplying warmth and sustenance, while her heartbeat provides a soothing constant rhythm," according to a recent article in Scientific American. This is nothing new to first mothers who well know that a piece of paper signed by a judge cannot destroy the connection constructed by nature. "The link between a mother and child is profound, and new research suggests a physical connection even deeper than anyone thought," writes Robert Martone.

It's reassuring to have what we know instinctively reaffirmed by science. The Journal article is reporting on research from the Fred Hutchinson Cancer Research Center in Seattle that found that cells from a developing fetus migrate through the placenta and end up in the mother's brain--as well as many other organs, such as the lung, thyroid muscle, liver, heart, kidney and skin. Male cells were found in the brains of women and had been living there, in some cases, for several decades. We think of ourselves as individual and
distinct human beings, acting on our own, but if we now think about having cells in our brains that originated with say, your mother-in-law through her grandson that you carried, the connectedness of us all becomes a very real concept and easier to grasp. The connection exists at the cellular level.

THE DANCE OF THE CELLS 

Lorraine

The study also notes that there is evidence that cells may transferred from mother to child through nursing, between twins in utero, and from an older sibling to a younger sibling during gestation--after all, they shared the same space in the womb and the elder child left some cells behind. Women may have cells from both their mother, as well as from their own pregnancies--which is how male cells show up in female organs. It would appear--we note with bemusement--that then the commonly noted and age-old feuding that goes on between sons' mothers and their daughters-in-law has in fact a basic biological connection, for the study further found that there is even evidence for competition between cells from grandmother (the mother-in-law) and infant within the mother.

Reading this we were reminded of a study heard the other evening on the nightly news, which we mused over at the time: one study found that men who had good marriages where likely to get on well with their mothers-in-law, but the opposite was not true: women in strong marriages did not necessarily show the same affinity for their husbands' mothers. After hearing the study on the news, Lorraine recalled the old saying: A daughter is a daughter all of her life; a son is a son until he takes a wife.

ADOPTED OR NOT, OUR CHILDREN LIVE ON IN US
We know this is a long stretch here--we are talking about a few cells duking it out--but the more we learn about life, the more we see psychological patterns having biological underpinnings. We both have written numerous times--as Jane did just the other day--about the biological connection between ourselves, and our children, adopted or not, and here we have an example of our children's cells living for decades in our brains. Is it any wonder we can't just put behind the loss of our children that adoption was to us and move on? Fascinating to ponder, but we digress.

Jane

The scientific name for this dance of the cells, or the persistent presence of a few genetically distinct cells in an organism, is microchimerism. As Martone notes, it was first noticed in humans many years ago when cells containing the male “Y” chromosome were found circulating in the blood of women after pregnancy. Since these cells are genetically male, they could not have been the women’s own, but most likely came from their babies during gestation.

What's the value of these migrating cells which the scientists call fetal microchimeric cells? They are similar to stem cells, cells able to grow into a variety of different kinds of cells, and may aid in tissue repair in all parts of the body. They may also stimulate the immune system to stem the growth of tumors.

The report did not discuss the cellular impact, or transfer of cells, when a woman carries a child who does not carry her genes, as in the case of surrogacy with eggs from another woman. Now that is a study we would like to see done. If a fetus naturally sloughs off cells, it is hard to imagine that the process would be any different with a fetus developed with eggs from a stranger. --lorraine and Jane
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SOURCES
*Robert Martone, "Scientists Discover Children's Cells Living in Mothers' Brains: The Connection between mother and child is even deeper than thought" 12/4/1
 Effect of parity on fetal and maternal microchimerism: interaction of grafts within a host?

From FMF
Can feminism be hereditary?
Biology is irrelevant, judge rules in gay custody battle

FURTHER READING
The Agile Gene: How Nature Turns on Nurture "In the follow-up to his bestseller, Genome, Matt Ridley takes on a centuries-old question: is it nature or nurture that makes us who we are? Ridley asserts that the question itself is a "false dichotomy." Using copious examples from human and animal behavior, he presents the notion that our environment affects the way our genes express themselves."--Amazon.

And from Publisher's Weekly: "Nature versus nurture" sums up in a nutshell one of the most contentious debates in science: Are people's qualities determined by their genes (nature) or by their environment (nurture)? The debate has only grown louder since the human genome has been found to comprise only 30,000 genes. Some scientists claim that we don't have enough genes to account for all the existing human variations. Ridley...says that not only are nature and nurture not mutually exclusive, but that 'genes are designed to take their cue from nurture.'"

Lorraine adds: I find the nature/nurture discussion fascinating. This is a book I'm going to get. As for how did microchimerism get its name? Think of Chimera, the creature in Greek mythology that was part serpent, part lion, part goat. Some combo, eh? But truly in nature, the mixing of cells from genetically distinct creatures is not at all uncommon. Called chimerism, it biologically includes corals and, er, slime mold. And now, us.