Chapter 1 – Brain Development

The human brain has been described as the most complicated biological object in existence. Yet the brain is the substrate for sophisticated human behavior, so perhaps it’s complexity is predictable. The development of the brain follows a genetic blueprint and this blueprint organizes basic structures and connections in the brain. But brain development is also sensitive to the environment. An individual’s experiences can dictate connections to be dismantled or retained in the wiring circuitry of the brain. Two main cell types, neurons and glia, comprise the brain and they appear in various forms at different phases of brain development. In maturity, the brain has approximately 86 billion neurons and about the same number of glial cells. The process of transforming the embryonic neural plate to the exquisitely complex and fully developed brain, is the topic of discussion in this chapter.