Expression of Na/K-ATPase subunits in the human cochlea : a confocal and super-resolution microscopy study with special reference to auditory nerve excitation and cochlear implantation

• Background: For the first time the expression of the ion transport protein sodium/potassium-ATPase and its isoforms was analyzed in the human cochlea using light- and confocal microscopy as well as super-resolution structured illumination microscopy. It may increase our understanding of its role in the propagation and processing of action potentials in the human auditory nerve and how electric nerve responses are elicited from auditory prostheses.Material and methods: Archival human cochlear sections were obtained from trans-cochlear surgeries. Antibodies against the Na/K-ATPase beta 1 isoform together with alpha 1 and alpha 3 were used for immunohistochemistry. An algorithm was applied to assess the expression in various domains.Results: Na/K ATPase beta 1 subunit was expressed, mostly combined with the alpha 1 isoform. Neurons expressed the beta 1 subunit combined with alpha 3, while satellite glial cells expressed the alpha 1 isoform without recognized association with beta 1. Types I and II spiral ganglion neurons and efferent fibers expressed the Na/K-ATPase alpha 3 subunit. Inner hair cells, nerve fibers underneath, and efferent and afferent fibers in the organ of Corti also expressed alpha 1. The highest activity of Na/K-ATPase beta 1 was at the inner hair cell/nerve junction and spiral prominence.Conclusion: The human auditory nerve displays distinct morphologic features represented in its molecular expression. It was found that electric signals generated via hair cells may not go uninterrupted across the spiral ganglion, but are locally processed. This may be related to particular filtering properties in the human acoustic pathway.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Neurovetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Neurosciences (hsv//eng)

Keyword

Auditory nerve

cochlea

human

Na

K-ATPase

structured illumination microscopy

Publication and Content Type

ref (subject category)

art (subject category)