Developmental regulation of motor function: an uncharted sea

The field of developmental neurobiology is entering a very exciting phase, in which the application of new techniques promises to lead to major advances in our understanding of basic developmental processes. There is a need to apply much of this new knowledge to problems of spinal cord and muscle development, about which little is known at present. An understanding of the development of muscle fiber types and the spinal circuitry controlling locomotion would have a major impact on fundamental problems in motor control and exercise physiology. Significant progress is likely to be made in these areas in the next few years, but only if researchers interested in motor control and related areas take an interest in development. Among the most immediate problems that need to be addressed are: the lineage analysis of spinal neurons; identification of the factors controlling neuron differentiation; identification of the molecular basis for directed axon growth; and analysis of the factors controlling network assembly in the spinal cord. In muscle development, an understanding of how fiber type proportions are generated would have great significance for disciplines related to motor performance. The interaction and exchange of ideas between developmental biologists and exercise scientists promises to accelerate understanding and progress in both fields of endeavor.