Neural Crest Flashcards
What do neural crest cells become?
Peripheral nervous system, endocrine cells, pigment cells, facial cartilage and bones, connective tissues
When are the neural crest cells specified? Where do they come from?
Very early on in the ectoderm. They come from the edge between the neural tube and the epidermis
What happens to the neural crest cells as the neural tube forms?
They undergo an EMT, delaminate, and migrate to become various cell types
What determines what cell type a neural crest cell will become?
Where it came from and which migration path it’s following
What are the 4 types of neural crest cells?
Cranial, cardiac, trunk, vagal/sacral
What types of cells do the cranial neural crest cells become?
Neurons, glia, melanocytes, facial cartilage
What are the two migratory pathways trunk neural crest cells can take?
Dorsal and ventral
Which of the two migratory pathways is the default for the trunk neural crest cells?
Dorsal
What features arise from the trunk neural crest cells that went through the dorsal pathway?
Melanocytes - skin pigment cells
What features arise from the trunk neural crest cells that went through the ventral pathway?
Sensory neurons in the dorsal root, sympathetic nervous system, adrenal medulla
How are pigmentation patterns created?
Migration or death of melanoblasts
What are the 3 steps required for trunk neural crest cells to take the ventral pathway?
- Cells are blocked from taking the dorsal pathway
- First set of NCC migrate between the somites then are blocked
- Second set of NCC migrate through the anterior parts of the somites
What is the sclerotome?
Anterior side of somites
How do the somites keep the neural crest cells out of the posterior end of the somite?
They express ephrin and semaphorin-3F, which repulses the NCCs
Why do the neural crest cells need to migrate through the anterior end of the somite?
Keeps all the motor neuron axons in one place