7.1: Introduction

The nervous system develops in an intricately coordinated process from the early embryonic stages through childhood, adolescence, and adulthood. During early developmental stages, the brain develops the ability to dynamically transfer information across billions of interconnected neurons, and to coordinate and control mental and bodily functions, including perception, cognition, and movement.

In this chapter, we cover the stages of development of the human brain and nervous system. We examine prenatal and postnatal development from embryo through old age. We also cover different stages of neuronal development, including neuron growth, migration, and death, as well as adult neurogenesis. Lastly, we examine neuroplasticity—the brain’s ability to reorganize in response to experiences—and how neuroplasticity is strongest during sensitive and critical periods of development. Learning how the nervous system changes across the lifespan provides a more complete understanding of the brain.