Interactions of Segmental and Suprasegmental Inputs with the Spinal Pattern Generator of Locomotion

An important question in the field of motor control is how the neural networks responsible for generating movements integrate the sensory inputs produced by these movements, so that the resulting feedback does not disrupt their progression but instead serves in their regulation. One way in which this question can be approached is to study the characteristics of the feedback signal by recording the discharge of specific types of peripheral afferents, or of central neurones, in relation to the various movement parameters. This approach is usually based on the assumption that the resulting effects of the recorded activiby on the motor output can be derived from the effects that these particular neurones are known to have on motor neurones in motionless animal preparations. What if these effects are augmented, blocked or rerouted through pathways which are operative only in certain types of movements? Indeed, “what the cat’s hindlimb tells the cat’s spinal cord” and what the cat’s spinal cord listens to may be different.