ABSTRACT
The neural crest has an important role in the development of the neuroendocrine-immune network. The development of the interdependent elements is accomplished through an exquisitely timed series of differentiative steps, migrations, and interactions. This chapter discusses the salient features of the differentiation of these elements, including the interactive features which control them. It considers clinical observations which have been interpreted as the result of failures in proper development of the neural crest, and experimental studies in which developmental defects have been induced as a means of trying to understand the interactive mechanisms involved. The thymus is a central lymphoid organ which is necessary for the full development of the immune system. The neural crest, with contributions from neural placodes, provides much of the peripheral nervous system. Direct evidence of the importance of the neural crest in the development of thymus, thyroid, and parathyroids has come from experimental studies using chick embryos.
