The formation of the nervous system during embryonic development is a fascinating topic. The embryo begins as a flat disk with three layers, one of which is the ectoderm from which the skin and nervous system arise.
A part of the ectoderm gives rise to the neural plate. In the neural plate, a groove, called the neural groove forms, whose walls are called the neural folds. These folds fuse and form the neural tube. This is called neurulation.
The entire central nervous system develops from this neural tube.
Neural tube formation is a crucial piece in the development of the nervous system and it occurs only three weeks after conception. Failure of the neural tube to close correctly is a common birth defect, but can be prevented through proper maternal nutrition. The birth defect is linked to something that many women know about: folic acid.
Dietary folic acid supplementation can reduce the incidence of neural tube defects by 90%.
Failure of the anterior, or front, part of the neural tube to close results in anencephaly, which is characterized by a degeneration of the skull and forebrain and is always fatal.
Failure of the posterior, or end, part of the neural tube to close results in spina bifida. Though not fatal, spina bifida requires surgery and expensive medical care.
Good dietary sources of folic acid are spinach, liver, beans, eggs, and oranges.
The neural tube goes through a process of differentiation, or development of specialized parts. The first step in braindifferentiation is at the rostral end of the neural tube: three swellins called the primary vesicles.
The entire brain is derived from these three primary vesicles of the neural tube.
One of the vesicles is called the prosencephalon, also called the forebrain. Behind it is the mesencephalon, or the midbrain. The third vesicle is the rhombencephalon, or the hindbrain. The rhombencephalon connects with the neural tube at the caudal end to form the spinal cord.
It is easy to see how preventing problems with the neural tube is crucial for proper brain and nervous system development in a fetus.
My original article can be found here.