Modeling the Spinal Cord Neural Circuitry Controlling Cat Hindlimb Movement During Locomotion

The spinal cord neural circuitry was modeled as a network of interacting neuronal modules (NMs). Each NM includes a network of alpha-motoneurons, Renshaw, Ia and Ib interneurons, and interneurons associated with the central pattern generator (CPG). The CPG was integrated with reflex circuits. Each of two three-joint hindlimbs was actuated by 9 one- and two-joint flexor and extensor muscles. The objective was to find the network architecture within and between the NMs that provides stable locomotion with different gaits, realistic patterns of muscle activation, and limb movement kinematics. The results of modeling are discussed in the context of experimental data on cat locomotion