Creutzfeldt-Jakob disease. Light micrograph of a section through human brain showing Creutzfeldt- Jakob disease (CJD). Cell bodies of brain neurones (dark red) are surrounded by many white gaps or vacuoles. These vacuoles, as well as numerous starchy plaques (not seen here) are caused by a virus-like particle known as a prion. As CJD prog- resses, brain tissue becomes spongy and nerve cells are destroyed. Symptoms include dementia and sudden muscle contractions, leading to death. There is concern that eating beef from mad cows" may cause CJD in humans. Haematoxylin & Eosin stained cells."