neuralectoderm

Neural ectoderm, also called neuroectoderm, is the portion of the embryonic ectoderm that gives rise to the central nervous system and related structures. It forms during neurulation when the dorsal ectoderm thickens to form the neural plate, which folds to become the neural tube. The neural tube later differentiates to give the brain and spinal cord. The neural ectoderm also gives rise to the retina and optic nerve, the posterior pituitary (neurohypophysis), and various neural structures of the brain.

Development involves neural induction, in which signals from the underlying notochord and mesoderm inhibit BMP signaling in the overlying ectoderm to promote neural fate. Key transcription factors used early in the neuroectoderm include Sox2 and Pax6, with subsequent patterning along the anterior-posterior axis governed by organizers such as the anterior neural ridge and the isthmic organizer, as well as morphogens like Sonic hedgehog, Wnt, and BMP family members. Progenitor cells in the neural epithelium differentiate into neurons and glial cells, with radial glia providing scaffolding during early corticogenesis.

Derivatives of the neural ectoderm include cells of the central nervous system—neurons and glia—derived from the neural tube epithelium. The retina and optic nerve arise from neural ectoderm as part of the visual system, and the posterior pituitary develops from diencephalon neuroectoderm. Some brain regions originate from neural tube vesicles established during early development.

Clinical relevance includes neural tube defects, which result from failure of neural tube closure in early development; maternal folate supplementation reduces risk.