The effects of long-term lead intoxication on the nervous system of the chicken

In order to study the possible etiologic role of lead in human motor neuron disease we produced chronic lead intoxication in the chicken by daily administration of lead acetate. Control animals received sodium acetate. During life, periodic measurements were made of motor function, motor nerve conduction velocity and response amplitude. After sacrifice, histologic analysis was performed on spinal cord, peripheral nerve and muscle. A syndrome was produced characterized by a fall in motor response amplitude, spinal motor neuron degeneration, motor axonal loss and atrophy of muscle, similar to that seen in human motor neuron diseases.