FIG. 2.

Tools for weight supported overground and treadmill locomotion. In (A), the Circular Body weight supported Ambulatory Rat Trainer (CBART) 1 device, is shown. The rat is attached to one end of a lever arm. The lever arm pivots around a fulcrum. The rat is lifted (see vertical white arrows) by the weight on the opposite end of the lever arm. The amount of weight support is adjusted by moving the location of the weight on the lever arm. A small camera on the arm is used to video record the rat during locomotion. The lever arm also rotates around a vertical axis indicated by the white arrow. This allows the rat to walk in a circular path indicated by the black, dashed line and arrow. In (B), a second CBART device is shown. This CBART 2 device uses the same mechanical principles as the device in (A), but is made from parts (i.e., PVC pipe, caster) obtained from a hardware store. The inset shows a spinally contused rat undergoing treadmill training using the CBART 2 device (Supplementary Video 1; see online supplementary material at www.liebertpub.com).