[Locomotor control by the brainstem and spinal cord].

One of the fundamental characteristics of animal is locomotion. Although not visually apparent, goal-directed locomotor movements are always accompanied by automatic adjustment of muscle tone and postural reactions. Because the basic and essential mechanisms that control postural muscle tone and locomotion are located in the brainstem and spinal cord, a variety of locomotor behaviors are achieved by the projections from the forebrain structures (cerebral cortex, basal ganglia, and limbic-hypothalamic systems) and cerebellum to the brainstem-spinal cord. In this short review, we particularly focus on the role of the brainstem and spinal cord in the control of postural muscle tone and generation of locomotor rhythm. Abnormalities in the convergence inputs from the forebrain structures to the brainstem-spinal cord are further discussed in relation to the pathogenesis of disturbances in locomotor control.