neurulatie

Neurulation, known in Dutch as neurulatie, is the developmental process that forms the neural tube, the precursor to the brain and spinal cord. It begins with the neural plate, a specialized region of the ectoderm induced by signals from the underlying notochord and mesoderm. The plate folds to create the neural groove, with neural folds on each side, and the folds fuse to produce a closed neural tube.

In many vertebrates, the anterior portion of the neural tube forms primarily through primary neurulation, while the posterior portion develops through secondary neurulation, which involves canalization of a cell mass. Concurrently, neural crest cells arise at the border of the neural plate and migrate to form a diverse array of tissues, including peripheral neurons and glia, melanocytes, craniofacial cartilage, and parts of the adrenal medulla.

Molecularly, neurulation involves a balance of signaling pathways. Inhibition of BMP signaling in the dorsal ectoderm allows neural fate; SHH signaling from the notochord and floor plate patterns ventral identities; and WNT and FGF pathways contribute to posterior identity and neural crest formation.

Clinical relevance includes neural tube defects that can arise from failed closure, such as anencephaly and spina bifida. Periconceptional folate supplementation and maternal health optimization reduce risk. There is evolutionary conservation of the basic mechanism, though timing and the extent of secondary neurulation vary among species.