We seek to understand how neural programs for behavior are established and how these programs adapt to support learning. We use the mouse spinal cord as our model system for three key reasons. First, the mammalian spinal cord is known to contain autonomous circuits for simple behaviors and to be capable of supporting electrophysiological and behavioral examples of learning. Second, the sensory inputs and the motor outputs to the spinal cord can be well defined, providing clear external references for the information in spinal neural circuits. Third, cell-type specific control can be accomplished using a diverse collection of genetic tools generated by us and by other laboratories. The goal of this project is to study both the mechanisms and the roles of plasticity in the mammalian spinal cord, from development through adulthood. A multi-disciplinary approach will allow us to probe the molecular, cellular, circuit, and behavioral levels of plasticity and learning. This work will provide a new basic science perspective on how mammalian neuronal networks adapt and learn. Ultimately, we hope to use this understanding to generate novel strategies to advance the treatment of spinal cord injury and stroke.