Sensory and motor nerves are differently damaged in toxic peripheral neuropathies. Recent evidence indicates that the spinal cord components of these nerves are also affected. It is proposed to systematically evaluate physiological function of peripheral sensory and motor nerves, and their spinal cord connections, to determine the pathophysiological basis of the movement disorders that are the prominent features of peripheral neuropathies. Spinal reflex mechanisms will be assessed for degree and nature of dysfunction in cats with neuropathies induced by acrylamide and doxorubicin. Assessment of function in the component parts of the reflex arcs will then permit a determination to be made of the relative contributions made to neurological impairment by each of impaired peripheral nerve function and compromised spinal cord integration of proprioceptive information. Ultrastructural studies of the involved nerves will provide morphological corroboration of observed neurophysiological dysfunction.