In this project we built a special behavioral environment to study the contribution of the cortex in motor learning. The set up consisted of a treadmill combined with a virtual reality that can generate different sensory environments. We are monitoring how mice learn to run on the treadmill (its velocity, speed, start and stop) and we perform simultaneous recordings of the neuronal activity using two-photon microscopy. We hope to answer a long standing question regarding the necessity of the motor cortex in acquisition, generation and retention of new motor skills.