The nervous system is made up of different cell populations. These diverse cells interact to create a functioning brain. Understanding this cellular diversity and how they relate to each other is one of the major challenges of modern neuroscience. The biochemical and molecular specialization of the nervous cells defines function at different developmental stages. In other words, the micro-anatomy of the brain provides the basis for its biochemical and molecular properties, which can vary depending on the age of the child. In this section you will find information about the major components of the nervous system and how they change during neurodevelopment and in relation with different neuropaediatric disorders.