Molecular Basis of Axon Growth and Nerve Pattern Formation

Since the last Taniguchi Symposium on Brain Science dealt with the subject of developmental neurobiology in 1982 and again in 1985, the field has greatly advanced in several respects. Twelve years ago, our knowledge on the segmentation or compartmentalization of the vertebrate nervous systems was extremely fragmental. Today through a combination of transcription factors and cell-cell signaling molecules and their receptors, we can explain how regional specification of vertebrate brains is accomplished, and how the neuraxis is established in development. We also have several sets of molecules which play roles in the directional growth of axons and specification of neuron wiring. Advances in technology, particularly in gene manipulation techniques in mice, have enabled us to explore the exact functions of molecules or genes in the development of vertebrate nervous systems. Finally, the development of new experimental animal models, in particular zebrafish, has opened a way for genetic approach even to the vertebrate nervous systems. This timely publication presents a broad spectrum of developmental mechanisms on vertebrate nervous systems at molecular and cellular levels.