Brain Rules for Baby Read Online Free PDF Page A

creating the placenta and the water balloon in which the embryo will float, the amniotic sac. Certain cells are assigned the duties of constructing the embryo, creating a knot of internal tissues termed the inner cell mass.

    We need to stop right here and contemplate something: The inner cell mass at this stage possesses a cell whose entire offspring will form the human brain. The most complex information-processing device ever constructed is on its way. And it starts out a fraction of the size of the period at the end of this sentence.
    I have been studying this stuff for more than 20 years. I still find it amazing. As scientist Lewis Thomas put it in Lives of a Cell: “The mere existence of such a cell should be one of the great astonishments of the earth. People ought to be walking around all day, all through their waking hours, calling to each other in endless wonderment, talking of nothing except that cell”. Go ahead, call your neighbor; I’ll wait.
    The miracle continues. If you could see it in action, this embryo floating in seawater, you would notice that the inner cell mass is actually swarming with cells, scurrying around the embryo like busy short-order cooks at the county fair. The cells arrange themselves into three living layers, looking for all the world like a cheeseburger. The bottom bun, called the endoderm, will form most of the cell systems that line your baby’s organs and vessels. The burger layer, the mesoderm, forms his muscles, respiratory systems, digestive systems, and bones. The top bun is the ectoderm. It will create your baby’s skin, hair nails, and nervous systems. It is within the ectoderm that his miraculous little pre-brain cell resides.
    Looking closer, you would see the tiniest line of cells forming atop the bun’s center. Below that line, a log-shaped cylinder begins to form, elongating itself by using the overhead line as a guide. This cylinder is the neural tube. It will give rise to the spinal column—the far end of the log becoming your baby’s butt, the near end becoming your baby’s brain.
When something goes wrong
    It’s vital that this neural tube develop properly. If it doesn’t, the baby could have a protruding spinal cord or even a tumor near
his lower back, a condition known as spina bifida. Or the baby could grow without a complete head, a rare condition known as anencephaly.
    This is why every pregnancy book strongly recommends taking the B-complex vitamin folic acid: It helps shape the proper neural tube—both the near and far ends. Women who take it around conception and during the first few weeks of pregnancy are 76 percent less likely to create a fetus with neural tube defects than those who don’t take the supplement. It is the first thing you can do to aid brain development.
    Parents-to-be throughout history have worried about whether all of this is developing properly. In 1573, French surgeon Ambroise Paré catalogued the events to which prudent young pregnant couples should be alerted to avoid a child with birth defects. “There are several things that cause monsters, he wrote in On Monsters and Marvels. “The first is the glory of God. The second, His wrath. The third, too great a quantity of sperm. The fourth, too little a quantity of sperm”. Paré hypothesized that a birth defect could be caused by indecent posturing of mom (she sat too long with her legs crossed). Or it could be due to the narrowness of the uterus; demons and devils; or the wicked spittle of beggars.
    We can perhaps forgive Paré’s pre-scientific misunderstanding of in utero brain development. Even to the modern mind, it is scary, hopelessly complex, and mostly mysterious.
    Researchers today are at a complete loss to explain nearly two-thirds of all birth defects. Indeed, only a quarter of all known birth defects have been tied to an isolable DNA problem. One of the reasons we know so little is that mom’s body appears to have a fail-safe component. If something goes wrong