The developing brain

The brain is one of the most fascinating organs in the human body. It not only enables us to interact with our environment by integrating the information we gain through our senses, but also allows for creativity and the creation of things which have not existed before.

In particular in the early stages during development, the brain undergoes significant changes. The brain is considered to form when the neural plate closes and becomes the neural tube at around 3 weeks of post-menstrual age (PMA). After this point, three principal enlargements form, namely the forebrain (proencephalon), the midbrain (mesencephalon) and the hindbrain (rhombencephalon). Each of these enlargements will form an important part of what is called the adult human brain. The individual parts of the brain and what they develop into is shown in the next figure.

Early brain division and development

As we can see, the forebrain is split up into two parts, the diencephalon, which is the basis, for example, for our eyes, and the telencephalon, which forms the largest part of the human brain, the cerebral hemispheres. It is in the telencephalon, where most of our higher cognitive functions take place.

So far we have talked about what scientists call grey matter, the set of neural cells which are responsible for processing information. The name "grey matter" stems from the colour of the cell bodies. However, in order for the individual cells to communicate, white matter is necessary. These connections appear white due to the fatty material (myelin) that is used to insulate them and which increases their efficacy with respect to information transport. The development of both grey and white matter are described in more detail in their own sections (Grey matter and White matter). The following figure summarises the key parts of brain development during pregnancy.

Overview of human brain development

Sometimes babies are born too early (premature). One important question is how this event influences the development of the baby's brain. Prematurity and its effects are described in more detail in its own section.