Further data on experimental Creutzfeldt--Jakob disease (spongiform encephalopathy) in the guinea pig.

Intracerebral inoculation to guinea pigs of cerebrospinal fluid or brain suspensions from 6 patients with Creutzfeldt--Jakob disease was followed in 4 cases by the appearance, after a long incubation period, of a serially transmissible experimental disease. The disease was characterized by tremor, discrete ataxia and convulsions and led to a fatal outcome within several days. Microscopic lesions in the brain of guinea pigs with the experimental disease consisted in glial proliferation, spongiform change and vacuolation of neuron cytoplasm. Electron microscopy proved that the vacuoles were situated in the endoplasmic reticulum and in the cytoplasmic processes.