Locomotion is a basic motor behavior, crucial for everyday function. The neural control of locomotion is highly conserved amongst the different vertebrate species, where the spinal cord contains the neural networks that generate the basic muscle synergies and supraspinal structures initiate and control locomotion. One such supraspinal structure, the Mesencephalic Locomotor Region (MLR), is located in the brainstem, from where it controls swimming in fish, flying in birds, and walking in limbed animals. Twenty years ago, we identified the MLR in the lamprey, one of the most basal, extant vertebrates. This conference deals with the inputs and outputs of the vertebrate MLR based on what we learned from the lamprey.