Expression of myelin basic protein in the human auditory nerve—An immunohistochemical and comparative study

Liu, Wei; Boström, Marja; Kinnefors, Anders; Linthicum, Fred; Rask-Andersen, Helge

doi:10.1016/j.anl.2011.04.007

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Volume 39, Issue 1 , Pages 18-24, February 2012

Expression of myelin basic protein in the human auditory nerve—An immunohistochemical and comparative study

Wei Liu
- Dept. of Otolaryngology, Uppsala University Hospital, 75185 Uppsala, Sweden
- Corresponding author at: Department of Surgical Sciences, Section of Otolaryngology, Uppsala University Hospital, SE-75185 Uppsala, Sweden. Tel.: +46 18 6115456; fax: +46 18 500979.
Marja Boström
- Dept. of Otolaryngology, Uppsala University Hospital, 75185 Uppsala, Sweden
Anders Kinnefors
- Dept. of Otolaryngology, Uppsala University Hospital, 75185 Uppsala, Sweden
Fred Linthicum
- House Ear Institute, Los Angeles, CA, USA
- Otolaryngology/Head and Neck Surgery, The Keck School of Medicine of the University of Southern California, USA
Helge Rask-Andersen
- Dept. of Otolaryngology, Uppsala University Hospital, 75185 Uppsala, Sweden
- Corresponding author at: Department of Surgical Sciences, Section of Otolaryngology, Uppsala University Hospital, SE-75185 Uppsala, Sweden. Tel.: +46 18 6119445; fax: +46 18 500979.

Received 25 October 2010; accepted 22 April 2011.

Abstract

Objective

The aim of this study is to analyse the expression and distribution of myelin basic protein (MBP or Myelin A1 protein) in the human spiral ganglion and auditory nerve.

Materials and methods

Cryostat sections were made from freshly fixed human cochlear specimens removed at surgery in patients with life-threatening petro-clival meningiomas compressing the brain stem. The sections were subjected to immunohistochemistry using antibodies against MBP, S-100 and Tubulin. The immunoreaction was documented using laser confocal microscopy.

Results

Type I spiral ganglion nerve somata (SGN) were surrounded by so-called “satellite glial cells” (SGCs) that lacked expression of MBP consistent with earlier light and electron microscopic findings indicating that these cells are non-myelinating. S-100 labeling showed that the SGCs form a continuous network in the apical region.

Conclusions

The pattern of myelination in human spiral ganglion is different from that in other species’ spiral ganglion. The striking differences in myelin outline should be investigated further in combination with its influence on signal coding and preservation properties in man.

Abbreviations: SGN, spiral ganglion neurons, SGC, satellite glial cells, SG, spiral ganglion, HSG, human spiral ganglion, Type II SGN, spiral ganglion neurons innervating outer hair cells. These cells have been referred to as “small ganglion cells” in human, Type I SGN, spiral ganglion neurons innervating inner hair cells, MBP (or Myelin A1 protein), myelin basic protein, SC, Schwann cell, OC, organ of Corti