Forelimb movements in cats with complete or partial bulbar pyramid lesions.

Adult cats were trained to use a forelimb to open a hinged door against resistance for a food reward. Normal cats performed the task with only toe or wrist motions. Cats with unilateral complete bulbar pyramid section showed persistent deficits in distal limb movements with toe fanning, wrist stiffness and pulling from elbow and shoulder. Partial medial or lateral pyramid lesions produced similar but less severe effects. These results suggest a significant role of the corticospinal system in distal limb movements and a lack of topographical localization of pyramid fibers related to these movements in cats.