The diverse neural crest: from embryology to human pathology

The diverse neural crest: from embryology to human pathology

The capacity of NC cells to migrate all over the developing embryo and to settle in defined sites is unique in the vertebrate embryo.

NC cells turned out to be a population of highly multipotent, flexible, proliferative cells that migrate to various sites and are largely influenced in their terminal differentiation by environmental cues.

Multipotent NC progenitors and stem cells are not only present at early stages of migration and during the formation of NC derivatives, but they later persist in an astonishing number of tissues and organs of the adult.

Crucial to this wide distribution of NC-derived progenitors in time and space is the role of the vast network of PNS nerves, which convey and store multipotent NC cells of pre-glial identity (the SCPs).

The recently discovered broad distribution and versatility of NC-derived stem cells will spur future exploration of their molecular properties and responses to environmental signals. Multi-omics approaches, particularly those that have been recently developed at single cell resolution, will likely afford important novel insights into these questions in the near future.

After they have settled in their destination, NC cells fulfil multiple functions. By providing the body with the cells of the PNS, they play a major role not only in the coordination of organ functions, but also in adaptation of the organism to environmental conditions. One example of the role of the PNS is the vasoactive reactions to outside temperature; another is the efficient screen against UV radiation provided by melanocytes, a cell type of NC origin that expands, mainly in the skin. Moreover, NC-derived neuro-endocrine cells, such as those in the adrenal medulla and carotid body, enable response to environmental stress and further contribute to the maintenance of physiological homeostasis.

One of the most profound discoveries in NC research was that of its paramount role in building the vertebrate head. Among multi-cellular organisms, it is in vertebrates and, in particular, in humans that the brain has reached its most complex differentiation and acquired higher-level capacities. This has coincided with the development of sense organs and the elaboration of complex facial structures to enable and protect them, a function that has been accomplished by the cells of the NC.