Inhibitory interneuronal spinal cord network: organization and control of human voluntary movement and locomotion

Any locomotor or arbitrary movement is basically the result of the convergence of simultaneous descending and ascending commands into the motor centers of the spinal cord. An important link in the processing of incoming signals are the so-called «segmental interneurons» or «local interneurons», whose high concentration at the spinal level forms an inhibition interneuronal network. The role of this interneuronal network is to filter signals from muscle spindles, tendons, joints, skin, as well as signals coming from the higher parts of the central nervous system. In the presented review, based on the experimental data obtained so far, special attention is paid to the population of interneurons that are part of reflex arcs and their role in the implementation of inhibitory processes at the motor and premotoneuronal levels of neuroaxis, as well as the participation of the inhibition interneuronal network in the formation of motor output parameters. The role of supraspinal and suprasegmental mechanisms of neuromodulation of inhibitory interneuronal networks of the spinal cord in providing motor control is revealed.