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Abstract

This chapter discusses the migration of neural crest cells. The neural crest cell population of vertebrate embryos, starting from discrete origins, undergoes an ordered pattern of morphogenetic movements that result in the widespread distribution of these cells to form a complex pattern of derivatives. The onset of this cell dispersion seems to be permitted by the loss of cell–cell adhesions (including N-CAM and uncharacterized Ca2+-dependent mechanisms) and the ability of the cells to interact with their surroundings (e.g., cell surface receptors for appropriate extracellular matrix [ECM]). The process of dispersion of neural crest cells is partly due to passive carriage (where apparent displacement is actually due to growth and morphogenesis of the surroundings), to passive displacement (where true cell displacement occurs but is due to activity of the surroundings), and to active displacement. The chapter discusses patterns of migration for aves, mammals, and amphibia. The cells of the neural crest lineage eventually localize at defined positions and differentiate into a variety of cell types. The extent of dispersion of these cells is shown by their derivatives, which include not only sensory ganglion cells but also autonomic ganglion cells, Schwann cells, several endocrine and paracrine cell types, integumentary pigment cells, and in the head and neck, cells of connective, skeletal, and muscular tissues.