Thursday 15 December 2005

Pic of the day: Discovering this effect is much easier if your babies are genetically altered to glow in the dark. (Screenshot Sims2.)

Babies on the brain

I read a most awesome article in Scientific American for November 2005. It was shocking, icky and awe-inspiring. Not quite on the level of "New! Earth circles sun instead of the other way around!" but still, I can't understand why I haven't heard of this before. They should teach this in grade school.

Get this: At some time during pregnancy, fetal stem cells migrate from the little parasite to the mother's BRAIN. There, safe inside the blood/brain barrier, they proliferate. In varying parts of the brain they can make up one in 1000 cells or even 1 in 100. Not exactly enough to take over, admittedly, but still a definite presence. And they stick there after the child is born. In humans for up to 27 years. (I strongly suspect that this is simply the longest interval in the few mothers they have tested, there is hardly any scientific reason why the cells should suddenly commit collective suicide after 27 years. So make that "27 to life".)

Evidently this was entirely comme il faut, even though nobody had told me. The new news was that when the brain was damaged, the baby cells invaded the damaged area and multiplied to up to six times their normal number.

There is good reason for this, of course. Whether you believe in evolution or intelligent design (or intelligent evolution or something), the fact that babies depend on their mothers makes it a highly worthwhile investment to export some stem cells to her brain. The cells don't all remain stem cells either, but become quite normal brain cells only with a different genome. (For instance, baby boy stem cells retain their y chromosome. In mice, you can make them glow in the dark which makes it much easier to observe.)

Luckily the cells seem to be merely assisting. Even though they are more common in some parts of the brain, they are scattered and don't seem to form separate structures. So there is no reason to believe they are actually taking over the brain and rewiring the mother's behavior. (Although when confronting the mothers of some brats, they certainly seem a bit possessed...)

I guess the mothers deserve some compensation when you see what happens to their brain activity during pregnancy. No offense, but many women slow down noticeably intellectually as well as physically, and sometimes exhibit unusual behavior. I don't think this is caused by the fetal stem cells; evidently it is a mix of hormones partly from their own body and partly from the fetus. Intriguingly, they even secrete pheromones that alter the behavior of the male in the household. I guess the placental mode of reproduction must seem quite bizarre to any aliens that might observe us. But at least it now turns out to have some compensation. I can't imagine birds getting stem cells from laying eggs.

There is of course scientific value in this phenomenon, as we get to study the effect of fetal stem cells in the human brain by natural means. (Let's face, if anyone but God had done this, it would have been illegal and roundly condemned by all world religions and most political parties as well.) But most of all I can't shake the emotional impact of knowing that mothers actually physically carry a part of their children in their brain for decades. No matter whether the child is even still alive. That's just ... more awesome than me. I guess I wish I had known this when my mother was still alive, though I don't think I would have acted any differently.

I would even go so far as to say that it may influence the way I play The Sims 2...