Neural crest, ectodermal placodes and their derivatives

What does the neural plate border become?

the presumptive neural crest and placodes

The different neural crests all have different fates

Cranial or cephalic neural crest, Vagal neural crest, sacral neural crest, trunk neural crest

(Vagal) Neural crest cells give rise to

the valves and septa of the heart, the smooth muscle of the great vessels

Neural crest cell migration, through what?

Epithelial to Mesenchymal Transition (EMT)

Neural crest cell migration, important?

Lose contact, Establish polarity

Delamination

Neural crest cells loose their adhesive junctions and separate from the epithelium

contact inhibition

When neural crest cells contact one another, they experience contact inhibition, during which they will stop, turn and migrate away in the opposite direction

Neural crest cells as a model for ..., why?

tumor cells dissemination and cancer, they both migrate

similarities -> Cancer metastasis and neural crest cell migration

- Signalling pathways / molecules activated
- Transcription factors they initiate
○ E.g. Snail-2 - inhibits adhesion molecules
- Cadherin switches
- Cadherin shedding matrix remodelling
○ Creating a path
○ Done with proteases - cleaving proteins
○ Whatever they encounter - they shred to make path
- Make use of pre-existing structures to spread

Placode ?

local and temporary thickenings of the non-neuronal ectoderm

temporary structures that form mostly sensory cells (exception lens)

(Non-neuronal ectoderm origin)

Cranial placodes

-epidermal thickenings -produce delaminating sensory cells

(exception is the lens and adenohypophysal placode)

Cranial placodes and neural crest cells ?

coordinated and closely associated

The NC (neural crest) is?

an embryonic cell population characteristic of vertebrates

Do invertebrates have neural crests?

no, ONLY VERTEBRATES HAVE NEURAL CRESTS

How do the NCC (neural crest cells) exit from the dorsal neural tube?

by EMT, Epithelial Mesenchymal Transition

NCC migrate into the whole body along ..

stereotypic pathways. Have different routes

What do the Gene regulatory networks determine ?

the fate of the NCC

NCC share many characteristics with..

tumour cells

NCC share many features with ..

stem cells