Welcome to part VIII of Hearing International’s series honoring the Cochlear Explorers. This week’s explorer is Jean-Pierre Nuel (1847-1920), who was a Luxembourgian–Belgian ophthalmologist and physiologist. Recall that there are lots of cells and other structures within the body named after the researchers who first described them, and these are called Eponyms. Nuel’s name is lent to an area between the innermost hear cell and the outermost pillar of corti now known as The Space of Nuel.
The Space of Nuel
By perfusing perilymphatic compartments of the cochlea with fluorochrome-conjugated dextran, the extracellular spaces were clearly outlined. The staining pattern illustrated the large fluid compartments formed by the tunnel of Corti, the space of Nuel, and the outer tunnel. The dextran solution also indicated the spaces between the outer hair cell rows, the inner hair cells, and the surrounding supporting cells.
The staining pattern demonstrates that the organ of Corti has a loose structure, suggesting a weak mechanical coupling between the cells. Moreover, it is evident that substances applied to the perilymph (e.g., therapeutic drugs) will readily reach all the cells of the hearing organ. In addition to the intraorgan fluid compartments, the spiral limbus was shown to contain significant volumes of perilymph within the intercellular spaces forming the so-called teeth of Huschke between the interdental cells.
An extensive system of bundles following the teeth of Huschke was shown to be completely immersed in perilymph. The bundles were stained by a potentiometric dye, which in the inner ear primarily stains nerve fibers and sensory cells, which may indicate a nervous control of cells in this region.
Who Was Jean-Pierre Nuel?
Nuel was born in the small town of Tétange in Luxemburg in 1847, the third of 11 children. He received his education at the University of Ghent in Belgium established in 1817 by King William I of the Netherlands. After the Belgian revolution of 1830, the university was administered by the newly formed Belgian state. French became the academic language until 1930, when Ghent University became the first Dutch-speaking university in Belgium.
Jean-Pierre Nuel was awarded a medical degree from Ghent in 1870 and was licensed in surgery and in gynecology. He took up private practice, continuing his studies in Utrecht, Vienna, and Bonn. Nuel’s primary area of expertise was Ophthalmology, and he wrote articles and books on the basic aspects of vision and practical guides to surgery. However, he also conducted investigations of the Organ of Corti as a student during an 1871 summer semester at the Anatomical Institute in Bonn. He published a description of these dissections in 1872 in the Arch. Mikrosk Anat. (Archives of Microscopic Anatomy).
In his publication he emphasizes the introduction of two main concerns in cochlear anatomy: the fibers of the canalis cochlearis and the relationship between the hair cells and Dieters Cells. The bulk of his paper is devoted to detailed descriptions of these two topics, and he took issue with Bottcher’s work, which he considered, at least in part, to be decidedly incorrect (his exact words were “entschiden unrichtig”).
Later he turned his attention to the relationship between Dieters Cells and the hair cells, which was described some 10 years earlier, but still disputed. As discussed by Schacht & Hawkins (2004), Nuel grants the Dieters cells more independence or “Selbstständigkeit” than earlier authors did and he reiterates that the conical structures (or the phalanges) of Dieters Cells traverse at an angle reaching the reticular lamina approximately two hair cells to the side. His drawings emphasize the spaces between the pillar cells and the hair cells and also imply spaces between the phalanges of the Dieters Cells and the hair cells.
However, Nuel also uses this sketch to draw the reader’s attention to the bundles of appendages (“Buschel von Anhangen”) on the Corti cells, which he prefers to call the “little rods” (“Stabchen”) rather than hair cells.
Jean Pierre Nuel held professorships in Louvain, Belgium from 1877-1880, then became Chair in Ophthalmology and Physiology of Sensory Organs at the University of Liege, in Allonia, Belgium, where he remained until his retirement.