Florian Christov1,2, Erik G Nelson1, Lucy J Xu3, Ivan A Lopez4, Akira Ishiyama4, Michael B Gluth1. 1. Section of Otolaryngology-Head and Neck Surgery, University of Chicago, Chicago, Illinois, USA. 2. Department of ENT-Head and Neck Surgery, University Hospital RWTH Aachen, Aachen, Germany. 3. The University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA. 4. Department of Head and Neck Surgery, University of California Los Angeles, Los Angeles, California, USA.
Abstract
HYPOTHESIS: Outer sulcus cell features and distribution are hypothesized to differ throughout regions of the human cochlea and between diseased and normal specimens. BACKGROUND: Outer sulcus cells play a role in inner ear fluid homeostasis. However, their anatomy and distribution in the human are not well described. METHODS: Temporal bone specimens with normal hearing (n = 10), Menière's disease (n = 10), presbycusis with flat audiograms (n = 4), and presbycusis with sloping audiograms (n = 5) were examined by light microscopy. Outer sulcus cells were assessed quantitatively and qualitatively in each cochlear turn. One specimen was stained for tubulin immunofluorescence and imaged using confocal microscopy. RESULTS: Outer sulcus cells interface with endolymph throughout the cochlea, with greatest contact in the apical turn. Mean outer sulcus cell counts in the upper apical turn (8.82) were generally smaller (all p < 0.05) than those of the upper basal (17.71), lower middle (18.99) upper middle (18.23), and lower apical (16.42) turns. Mean outer sulcus cell counts were higher (p < 0.05) in normal controls (20.1) than in diseased specimens (15.29). There was a significant correlation between mean cell counts and tonotopically expected hearing thresholds in the upper basal (r = -0.662, p = 0.0001), lower middle (r = -0.565, p = 0.0017), and upper middle (r = -0.507, p = 0.0136) regions. Other differences in cell morphology, distribution, or relationship with Claudius cells were not appreciated between normal and diseased specimens. Menière's specimens had no apparent unique features in the cochlear apex. Immunofluorescence staining demonstrated outer sulcus cells extending into the spiral ligament in bundles forming tapering processes which differed between the cochlear turns in morphology. CONCLUSION: Outer sulcus cells vary throughout the cochlear turns and correlate with hearing status, but not in a manner specific to the underlying diagnoses of Menière's disease or presbycusis.
HYPOTHESIS: Outer sulcus cell features and distribution are hypothesized to differ throughout regions of the human cochlea and between diseased and normal specimens. BACKGROUND: Outer sulcus cells play a role in inner ear fluid homeostasis. However, their anatomy and distribution in the human are not well described. METHODS: Temporal bone specimens with normal hearing (n = 10), Menière's disease (n = 10), presbycusis with flat audiograms (n = 4), and presbycusis with sloping audiograms (n = 5) were examined by light microscopy. Outer sulcus cells were assessed quantitatively and qualitatively in each cochlear turn. One specimen was stained for tubulin immunofluorescence and imaged using confocal microscopy. RESULTS: Outer sulcus cells interface with endolymph throughout the cochlea, with greatest contact in the apical turn. Mean outer sulcus cell counts in the upper apical turn (8.82) were generally smaller (all p < 0.05) than those of the upper basal (17.71), lower middle (18.99) upper middle (18.23), and lower apical (16.42) turns. Mean outer sulcus cell counts were higher (p < 0.05) in normal controls (20.1) than in diseased specimens (15.29). There was a significant correlation between mean cell counts and tonotopically expected hearing thresholds in the upper basal (r = -0.662, p = 0.0001), lower middle (r = -0.565, p = 0.0017), and upper middle (r = -0.507, p = 0.0136) regions. Other differences in cell morphology, distribution, or relationship with Claudius cells were not appreciated between normal and diseased specimens. Menière's specimens had no apparent unique features in the cochlear apex. Immunofluorescence staining demonstrated outer sulcus cells extending into the spiral ligament in bundles forming tapering processes which differed between the cochlear turns in morphology. CONCLUSION: Outer sulcus cells vary throughout the cochlear turns and correlate with hearing status, but not in a manner specific to the underlying diagnoses of Menière's disease or presbycusis.
Authors: A Eckhard; A Dos Santos; W Liu; M Bassiouni; H Arnold; C Gleiser; B Hirt; C Harteneck; M Müller; H Rask-Andersen; H Löwenheim Journal: Pflugers Arch Date: 2015-07-25 Impact factor: 3.657
Authors: Natalia Trpchevska; Maxim B Freidin; Linda Broer; Berthe C Oosterloo; Shuyang Yao; Yitian Zhou; Barbara Vona; Charles Bishop; Argyro Bizaki-Vallaskangas; Barbara Canlon; Fabio Castellana; Daniel I Chasman; Stacey Cherny; Kaare Christensen; Maria Pina Concas; Adolfo Correa; Ran Elkon; Jonas Mengel-From; Yan Gao; Anne B S Giersch; Giorgia Girotto; Alexander Gudjonsson; Vilmundur Gudnason; Nancy L Heard-Costa; Ronna Hertzano; Jacob V B Hjelmborg; Jens Hjerling-Leffler; Howard J Hoffman; Jaakko Kaprio; Johannes Kettunen; Kristi Krebs; Anna K Kähler; Francois Lallemend; Lenore J Launer; I-Min Lee; Hampton Leonard; Chuan-Ming Li; Hubert Lowenheim; Patrik K E Magnusson; Joyce van Meurs; Lili Milani; Cynthia C Morton; Antti Mäkitie; Mike A Nalls; Giuseppe Giovanni Nardone; Marianne Nygaard; Teemu Palviainen; Sheila Pratt; Nicola Quaranta; Joel Rämö; Elmo Saarentaus; Rodolfo Sardone; Claudia L Satizabal; John M Schweinfurth; Sudha Seshadri; Eric Shiroma; Eldad Shulman; Eleanor Simonsick; Christopher Spankovich; Anke Tropitzsch; Volker M Lauschke; Patrick F Sullivan; Andre Goedegebure; Christopher R Cederroth; Frances M K Williams; Andries Paul Nagtegaal Journal: Am J Hum Genet Date: 2022-05-16 Impact factor: 11.043