Neuromotor disease and insult negatively affect the lives of millions of people worldwide. In some cases, such as severe spinal cord injury (SCI), a completely functional central nervous system is abruptly disconnected from the completely functional body. Currently, there is no therapy capable of promoting recovery after complete spinal cord injury. While our understanding of the organization of the brain has advanced dramatically in recent years, there have been few successes building a complete system to enable people in such states to regain the ability to interact with and control their environment. Two clinical approaches to treatment have been used: one where brain scientists and engineers have developed cortical implants to record and decode the intended movement for prosthetic control, and one where robotic assisted rehabilitation of the damaged area is driven by coordinated electrochemical stimulation. These two neural interface technologies paint the background of the proposed research. Expertise in the design of brain machine interfaces combined with the advanced spinal neuroprosthesis developed in the host laboratory open the intriguing possibility to merge both approaches, and pioneer a brain spinal interface (BSI) system capable of restoring movement in severely paralyzed subjects. Consequently, this project addresses two critical and clinically applicable hypotheses for the fusion of population decoding in the brain and electrochemical stimulation of the spinal cord after complete or partial SCI. First, after complete SCI, a BSI may re-establish cortical control over a library of spinal cord stimulation paradigms, thus restoring a range of voluntary locomotor functions in paralyzed rats. Second, training enabled by a newly developed BSI in rats with a severe spinal cord contusion may enhance remodeling of supraspinal and spinal neural systems, thus leading to significantly improved recovery compared to training with electrochemical stimulation alone.