Formation of neural tube:

1. Ectoderm over notochord thickens – forms neural plate (from primitive node to buccopharyngeal membrane)
2. Neural groove appears and deepens
3. Neural folds grow towards each other medially and fuse at the 4th somite
4. Fusion continues cranially and caudally forming neural tube
5. Edges of neural tube form neural crests
6. Cranial neural pore closes at 20th somite stage
7. Caudal neural pore closes at 25th somite stage

Neural tube forms brain and spinal cord