Herbert Major on the insula: An early depiction of von Economo neurones?

Abstract

Herbert Major (1850–1921) undertook histopathological studies of human and non-human primate brains at the West Riding Lunatic Asylum in Wakefield, England, during the 1870s. Two of his papers specifically investigated the structure of the island of Reil, or insula, “with the view of ascertaining its exact structure”. In addition to describing and illustrating its lamination as six-layered, Major also identified “spindle-shaped” cells in the lower layers of human brains, but not in non-human primates. His written description, including measurements of cell body size, and illustration are suggestive that these were the neurones later described in the frontoinsular and anterior cingulate cortex by Constantin von Economo and Georg N. Koskinas and which were subsequently given the eponym “von Economo neurones”. von Economo noted that this special neuronal type had been previously seen by Betz (1881), Hammarberg (1895), and Ramón y Cajal (1899-1904), but he did not mention Major’s works. Major also ascribed linguistic functions to the insula. Hence, with respect to both anatomical and physiological features, Major may have pre-empted the findings of later research on this structure.