Brain development

Brain development

1. Dorsal induction

   • Takes place from 18 to 26 days of gestation. On day 18 the developing embryo (still only a small clump of cells)
     • During this phase there is further folding, thickening and stretching out of the neural tube.

2. Ventral induction

   • Takes place from 4 to 10 weeks of gestation. This is the second stage of CNS development.
     • A number of brain structures are formed during this phase.

3. Proliferation

   • Is the third stage of CNS development. Proliferation is a two-phase process consisting of neuroblasts and glioblasts.

4. Migration

   • Begins at 6 to 8 weeks of gestation through 8 months gestation. This is the movement of nerve cells from the proliferation zone
     • Children who are born prematurely are delivered during the later part of the migration period.

5. Organization

   • Begins at 6 months of gestation and continues well after birth.
     • Once formed and in place, neurons begin to sprout branches referred to as axons and dendrites

6. Myelination

   • Begins at 6 months of gestation and continues into adulthood
     • The glial cells produce myelin. Myelin is a fatty covering that eventually coats and insulates many axons to provide for rapid impulse transmission.