The effects of diphtheria toxin on developing peripheral myelin in culture

Abstract

Whilst diphtheria toxin exerts its major effect upon myelin sheaths, nerve cells, Schwann cells and axis cylinders are also affected in varying degree in young immature cultures. Nerve cell changes indeed occur early at the electron microscopic level and only spread to axis cylinders, but a considerable proportion of these, especially when thin and not encompassed by damaged Schwann cells, are quite resistant to the action of the toxin. Diphtheria toxin holds back the further development of myelin once this has begun.