Use of robotics in assessing the adaptive capacity of the rat lumbar spinal cord.

We have developed a robotic device that can record the trajectory of the hindlimb movements in rats. The robotic device can also impose programmed forces on the limbs during stepping. In the present paper we describe experiments using this robotic device, i.e. the rat stepper, to determine whether step training improves the locomotor capacity of adult rats that received complete spinal cord transections as neonates. We also determined to what extent the locomotor patterns can be maintained when the step cycle is physically perturbed by the robotic device. The results of the present study demonstrate that a robotic device can be used effectively to quantify the improvements in the locomotor capacity of spinal transected rats that occurs over a period of step training. The present results also demonstrate that when an external force is imposed to disrupt the step cycle, the spinal cord has the neural control elements necessary to normalize the kinematics over a number of steps, in the face of the disrupted forces.