Nervous systems allow human beings to send and receive messages and to process impulses occurring in their bodies. These impulses are sent and received by nerves, which are are bundles of peripheral axons that run to various organs and tissues throughout the human body. The human body’s process of creating its nervous systems is called neural development. Development of the neural system can take place throughout a person’s entire life - from embryonic development to adulthood.
The importance of proper neural development can be seen on a daily basis. Consider, for example, the functions that take place when a person touches a hot stove. When the stove is touched, nerve impulses communicate this interaction by sending signals through the nerve network to the person’s brain. Neurons, also called neural cells, tell the brain that the stove is too painful to touch and that the hand should be moved away from the stove.
Neural development focuses on the central, the peripheral, and the autonomic nervous systems. The central nervous system, which includes the brain and spinal cord, issues nerve impulses and evaluates sensory information. The peripheral nervous system takes nerve impulses to and from the body and its structures, and the autonomic nervous system controls vital organ function. Although the structure of the nervous system appears about 18 days after conception, it usually starts to become functional during the second prenatal month.
At the embryonic stage, several key neural development processes typically take place – neurulation, formation of the spinal cord, and formation of the brain. During neurulation, the neural tube is formed from the embryo’s ectoderm. The spinal cord is then eventually formed from the lower part of the neural tube while the brain is formed from the upper portion.
Scientists who specialize in neuroscience or developmental biology study, among other things, neural development processes. Typically, they seek to shed light on the cellular and molecular mechanisms by which the nervous systems form. They may examine everything from nervous system patterns and regionalization, neural stem cells, and synapse formation to axonal and dendritic development, neuronal migration, and trophic interactions.
Deficiencies in neural development can result in cognitive, motor, and intellectual disabilities. If the defects are severe enough, they can result in neurological disorders like Rett syndrome, mental retardation, epilepsy, and autism. Many neural development problems surface during middle age. Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease are some examples of neurological conditions that manifest themselves later on in life.