Neural crest Flashcards
Is the neural crest an ectoderm, mesoderm or endoderm derivative?
Ectoderm
What is the neural crest?
Group of cells that form entire PNS + other stuff
Which tissues can the neural crest give rise to?
- Bone
- Melanocytes (skin cells)
- Cartilage cells
- Neurons
- Support cells of PNS (Glial cells)
When do we start to see the neural crest cells?
When neural tube closes (flat sheet of ectoderm folds up and fuses at its dorsal midline)
These cells come away from dorsal part of neural tube as it’s closing + start to migrate away from ectodermal neural tube (STILL STEM CELLS)
What kind of transition do the neural crest cells do?
Epithelial -> mesenchymal
Where do neural crest cells originate from?
Most dorsal region of neural tube
What kind of morphogen defined the region in what the neural crest cells will produce?
BMP (Bone Morphogenic Proteins)
Neural crest cell derivatives
- Neurons + glia of sensory, sympathetic and parasympathetic nervous systems
- Epinephrine
- Odontoblasts
- Pigment containing cells of epidermis
- Much of head skeleton + connective tissue
Fate of neural crest in the trunk region (Trunk crest)
- Schwann cells
- Sensory neurons of the DRG (remain in sclerotome, somite region)
- Sympathetic ganglia
- Melanocytes (migrate DORSOLATERALLY into ectoderm and continue towards midline)
- Nociceptor (pain)
- Proprioceptor (position and movement)
Why do n.c.c that come away from developping neural tube only migrate though ANTERIOR PORTION of each somite?
They make a receptor for a protein made in POSTERIOR part of somites => causes repulsion action
=> negative signal “get away from me”
Are NC cells multipotent, pluripotent or totipotent?
Multipotent
=> Pluripotency becomes more restricted as NC ages
=> Chick NC that migrate first can form a wide range of derivatives
What do later NC become?
Mostly melonocytes
How does a NC cell become a schwann cell?
Contact with an axon (it gets stimulated)
Why are many axonss coated with a myelin sheath?
This helps with the saltarory conduction of the action potential => increases the speed of propagation of the action potential
What are glial cells?
Support cells of the PNS
