Advances in understanding the development of the nervous system.

Over the past several years remarkable progress has been made towards unraveling the complex mechanisms that regulate neuronal development. Because the end results of abnormalities in brain development are often developmental disabilities, it is timely to review several recent advances in the field of neurobiology. This review, with contributions from several co-authors, provides a synopsis of breakthroughs from the fields of embryology, cell biology, and molecular genetics that hold promise for exciting clinical application. This article is arranged to reflect the stages of normal development. Understanding the mechanisms underlying neuronal induction, regional specification, neuronal specification, migration, axonal growth, neurotrophic factors, and myelination should clarify the pathophysiology of numerous neurological disorders, and provide new insights into their treatment.