Neural Crest Cell Differentiation

neural crest cell differentiation

Neural crest cells

The neural crest cells develop into numerous and varied cell types and migrate to regions far anterior (ventral) from their site of origin

Neural crest cell derivatives

Basic derivatives

Cranial neural crest cell derivatives

Trunk and lumbosacral neural crest cell derivatives include:

neural tube: primary brain vesicles

Primary brain vesicles

From anterior to posterior:

Neural crest cell organization

Neural crest cells originate along the midline of the dorsal aspect of the neural tube.
Somites lie lateral to them.

Placodes

The placodes are areas of thickened surface ectoderm that play an integral role in development of key cranial nerves (CNs 1, 2, and 8 – the solely sensory set) and also contribute to the development of merge the pharyngeal arch cranial nerves along with the neural crest cells.
Examples of placodes:

The olfactory placode forms the olfactory nerves and epithelium.
The lens placode forms the optic nerve.
The geniculate placode contributes to the development of cranial nerve 7 (along with the neural crest cells of the 2nd pharyngeal arch).
The otic placode forms the vestibulocochlear nerve.

neural crest cell development

Superior view

Folding of the neural plate into the neural tube is key to the development of the neural crest cells.

Day 18

Trilaminar germ disc

From top to bottom, the trilaminar germ disc comprises ectoderm, intraembryonic mesoderm, and endoderm.
Mesoderm comprises somites and notochord (which induces the overlying ectoderm to form the neural plate).

Then, draw the underlying endoderm.

Along the floor of the ectoderm lies the neural folds (again the neural crests are the neural fold tips).
The neural groove is the floor of the neural tube.

Day 21

The neural folds abut centrally, first, and remain open at their ends anteriorly and posteriorly.
The neural crest lies along the dorsal neural tube.

Elsewhere we see that this is the roof plate of the neural tube and is biologically influenced by the neural crest cells.

Day 23

The neural tube is folded a long distance along its center but remains open at the anterior (cranial) and posterior (caudal) neuropores.
The somites are visible, centrally, where the neural folds abut.
The somites generate bumps that appear on the surface of the overlying neural tube.
The neural crest cells make their migrations ventrally.

neural crest cell migration

Relevant structures:

Ectoderm
Mesoderm
Neural tube
Notochord
Dorsal aorta
A portion of the Gut Tube
Somites (the paraxial mesoderm), which forms axial musculoskeletal elements, from lateral to medial:

Dermatome (dermis)
Myotome (muscle)
Sclerotome (skeleton): it migrates to form around the neural tube as the spine and posterior basal occipital bone.

Peripheral nervous system derivatives

Portions of Cranial Nerves: 5, 7, 9, and 10 (the Pharyngeal Arch cranial nerves) and portions of CNs 3 and 8, as well.
Dorsal root ganglia
Sympathetic chain ganglia
Adrenal medulla (the chromaffin cells)
Prevertebral ganglia
Enteric nervous system

Additional neural crest cell derivatives

Don't forget, however, that the neural crest cells are responsible for much more than the aforementioned peripheral nervous system derivatives.

Other elements include:

Additional peripheral nervous system cellular structures:, for instance – glial cells and Schwann cells.
Melanocytes
Inner meningeal layers (pia and arachnoid - [the leptomeninges)
Musculoskeletal elements of the head and neck, such as the key cartilages and ear bones (learned elsewhere).