Figure 2: Process of NTC.

A) NTC begins with a flat sheet of epithelial cells (NE cells shown in green, NNE cells shown in blue) overlaying the notochord (yellow) and mesoderm (pink). B) Convergent extension and proliferation drive the bulging of the mesoderm and formation of neural folds. C) Actomyosin contractions form medial and dorsolateral hinge points as neural folds bend and approach one another. D) Neural folds adhere to partner tissue and fuse, forming intact neural tube covered by NNE