Role of Renshaw Cells in the Mammalian Locomotor Circuit: A Computational Study

In this study we considered the role of the inhibitory interneurons known as Renshaw cells (RC) in the activity of a simulated locomotor neural network. We used a n integrate-and fire-model to reproduce RCs experimental three-phases responses, consisting of a fast activation, a relaxation time and a slow activation. Simulations of RCs within a model of muscle spindle reflex neural network highlighted multiple roles of Renshaw cells in locomotion. We found that RCs synchronize the pool of motor neurons (MNs) they act on, and regulate the relative duration of the antagonist muscle bursts during the gait cycle. This refined model can be used to simulate the interaction between electrodes and spinal circuits to improve the efficacy of spinal cord stimulation protocols.