Experimental autoimmune motoneuron disease.

An animal model of disease of the lower motoneurons has been developed by inoculating guinea pigs with bovine motoneurons. Four of 9 immunized female animals and 4 of 5 immunized male animals developed symptoms of neuromuscular degeneration marked by weakness, evidence of denervation by electromyographic and morphological criteria, and a loss of motoneurons within the spinal cord. No inflammatory foci were noted within parenchyma or meninges of the central nervous system. The immunized guinea pigs developed high serum titers of IgG class antibodies to motoneurons. Immunohistochemical studies demonstrated the presence of IgG within spinal cord motoneurons and at the end-plates of immunized animals. This experimental autoimmune motoneuron disease may provide important insights into the cause and pathogenesis of amyotrophic lateral sclerosis, a human motoneuron disease.