Herbert Mayo’s (1796-1852) Forgotten Legacy: Mapping the Brain’s White Matter in Early 19th Century Neuroscience

Introduction: The early 19th century witnessed the evolution of British anatomical physiology symbolized by Harvey, Willis, and Hunter, into a search for cerebral functional localization. British surgeon and distant relation of the American Mayo brothers, Herbert Mayo (1796-1852) championed this novel fusion of physiology and anatomy, alongside Charles Bell, his teacher. Known for elucidating the motor and sensory functions of the 5th and 7th nerves, Mayo separately developed an intense interest in brain fiber tract anatomy. The impact of his work is significant given the increasing clinical relevance of fiber tract anatomy and imaging to neurosurgery. We review his contributions to neuroanatomy in the context of his professional life as a surgeon and of early 19th century neuroscience.

Methods: We examined Mayo’s Royal College of Surgeons archive, atlases, books, articles, letters, brain atlases of Bell and J.C. Reil. We also studied works of prominent 19th and 20th century scientists who referenced his research.

Results: Mayo translated Reil’s brilliant works from German into English. Mayo refined Reil’s dissection techniques, adding novel means for tissue preservation to better reveal the complexity of white matter tracts. At age 26, he created exquisite illustrations of fiber tract anatomy for his Commentaries (1822-1823) and masterful Engravings (1827). He performed the first accurate dissections of the brainstem, demonstrating the superior, middle, and inferior cerebellar peduncles.

Conclusion : Mayo’s highly skilled and original depictions of white matter tracts from novel dissection and tissue preservation techniques were arguably the best prior to Klingler’s 1930s works. Nevertheless, Mayo’s work has been neglected. Several explanations are possible: his tumultuous relationship with the influential Bell; his controversial application for a second professorship while simultaneously holding another; he later became an advocate of mesmerism and hydrotherapy, which would be discredited. Despite his unusual life, Mayo’s contributions to brain anatomy are vast, and deserve attention and further study.