ABSTRACT
Neural development is the process by which the nervous system with all its components comes into existence. It entails the cellular basis and the underlying mechanism that guide the developmental process, including neural induction, cellular differentiation, migration, axonal guidance, and synapse formation. This process starts during the third week of gestation, when the neural ectoderm forms the neural plate, which eventually becomes the neural tube. The neural tube is the origin of most of the neurons and glial cells. Dorsolateral to the neural tube, the neuroectodermal cells constitute a distinct group of cells, the neural crest cells, which give rise to the autonomic and sensory ganglia as well as other structures. Closure of the neuropores initiates the development of the brain vesicles, leading to the formation of various compartments of the central nervous system (CNS). Failure of closure of the neuropores results in variety of malformations ranging from anencephaly to spina bifida. Further differentiation of the primitive neural tube leads to the formation of the ependymal, mantle, and marginal layers. Division of the mantle layer into alar and basal plates accounts for the selective pattern of localization of the sensory and motor nuclei in the developed CNS. The neural canal converts into various parts of the ventricular system. Developmental defects of the nervous system can lead to motor, sensory, and cognitive dysfunctions.
