Abstract

Evidence is presented which indicates that the initial site of action of the pathogen of motor neurone disease (MND) is the nucleus, and its prime effect is to cause the progressive inhibition of DNA directed mRNA synthesis by the slow condensation of chromatin from a metabolically active diffuse form to an inactive form. The other pathological changes observed follow as part of a nonspecific cell atrophy which leads eventually to dysfunction, death, and disappearance of cells.