Synaptic specificity: development of locomotor rhythmicity

The basic neural networks that generate rhythmic locomotor movements in vertebrates are present in the spinal cord at very early stages in ontogeny, and these pre-existing circuits are then modified during development to perform more complex adult locomotor functions. Current research on the mechanisms responsible for the maturation of early locomotor circuits suggests that the descent of modulatory brainstem control systems may be particularly important for restructuring immature spinal networks so that they impart greater flexibility and control of their motor output.