Neurogenesis and specification of neuronal identity.

Abstract

Neural development unfolds with remarkable speed in zebrafish embryos where early neurons extend axons in a cell-specific pattern by the first day of development and a functional, though still growing, nervous system permits free-living larvae to hatch from their chorion shells by the second day of development. The relative simplicity of the early nervous system in zebrafish make it attractive to explore mechanisms that determine how specific types of neurons and glia are made in the correct number and location. In this chapter, we will first briefly describe the organization of different cell types in the early zebrafist nervous system and then discuss mechanisms responsible for establishing their organization. Since an exhaustive description of the anatomy and neurogenesis in the entire neural tube would be beyond the scope of this book, we will emphasize studies related to the development of the spinal cors.