The ultimate question: why do axons degenerate? A tribute to the work and mentorship of John W. Griffin, MD.

Axonal degeneration is a common pathological feature of neurodegenerative diseases. The underlying mechanisms for axonal degeneration, as well as for day to day maintenance of axonal integrity are just now coming to light. This short review outlines some of the historical landmarks in axonal degeneration research, focusing on the contributions of the late John W. Griffin. The importance of axonal degeneration in the pathogenesis of neurodegenerative disorders of the central and peripheral nervous systems is emphasized.