Gap junction systems in the mammalian cochlea

  title={Gap junction systems in the mammalian cochlea},
  author={Toshihiko Kikuchi and Robert S. Kimura and David L. Paul and Tomonori Takasaka and Joe C. Adams},
  journal={Brain Research Reviews},
Recent findings that a high proportion of non-syndromic hereditary sensorineural hearing loss is due to mutations in the gene for connexin 26 indicate the crucial role that the gene product plays for normal functioning of the cochlea. Excluding sensory cells, most cells in the cochlea are connected via gap junctions and these gap junctions appear to play critical roles in cochlear ion homeostasis. Connexin 26 occurs in gap junctions connecting all cell classes in the cochlea. There are two… Expand
Gap Junction Organization in the Mammalian Cochlea
Gap junctions play a critical role in hearing and mutations in connexin genes cause a high incidence of human deafness. Pathogenesis mainly occurs in the cochlea, where gap junctions form extensiveExpand
Gap Junctions and Cochlear Homeostasis
These studies elucidate gap junction functions in the cochlea and provide insight for understanding the pathogenesis of this common hereditary deafness induced by connexin mutations and functional studies of mutant channels that cause human deafness. Expand
Potassium ion recycling pathway via gap junction systems in the mammalian cochlea and its interruption in hereditary nonsyndromic deafness
The association of sensorineural hearing loss with genetic disorders provides strong evidence for the necessity of gap junction systems for the normal functioning of the cochlea and mutations of connexin genes that result in human nonsyndromic deafness cause dysfunction of cochlear gap junctions. Expand
Connexins in the Inner Ear
This chapter summarizes current knowledge about the molecular and functional properties of inner ear gap junctions and the inner ear pathologies associated with connexin mutations. Expand
Inner Ear Connexin Channels: Roles in Development and Maintenance of Cochlear Function.
  • F. Mammano
  • Medicine, Biology
  • Cold Spring Harbor perspectives in medicine
  • 2018
Reducing connexin 26 expression by Cre/loxP recombination in the inner ear of adult mice results in a decreased endocochlear potential, increased hearing thresholds, and loss of >90% of outer hair cells, indicating that this connexIn is essential for maintenance of cochlear function. Expand
Gap junctions and connexins in the inner ear: their roles in homeostasis and deafness
Despite recent advances, a better understanding of the complexity of gap-junctional communication in the inner ear and the structure–function relationships of connexin proteins is required for the development of mechanism-based treatments of Connexin-associated hearing loss. Expand
Connexins and gap junctions in the inner ear – it’s not just about K+ recycling
The current knowledge about the molecular and functional properties of inner ear gap junctions, and about tissue pathologies associated with connexin mutations, is summarised. Expand
Cell-cell junctions: a target of acoustic overstimulation in the sensory epithelium of the cochlea
This study employed graded dextran-FITC, a macromolecule tracer that is impermeable to the organ of Corti under physiological conditions, to evaluate the barrier function of cell junctions in normal and noise-traumatized cochlear sensory epithelia and revealed a general spatial correlation between the site of sensory cell damage and the sites of junction disruption. Expand
Compartmentalized and Signal-Selective Gap Junctional Coupling in the Hearing Cochlea
Data are supportive of the appearance of signal-selective gap junctions around the onset of hearing, with specific properties required to support auditory function, and suggest that separate medial and lateral buffering compartments exist in the hearing cochlea, which are individually dedicated to the homeostasis of inner hair cells and outer hair cells. Expand
Gap-junction channels dysfunction in deafness and hearing loss.
It is proposed that connexin channels (gap junctions and hemichannels) may be targets for age-related hearing loss induced by oxidative damage. Expand


Gap junction systems in the rat vestibular labyrinth: immunohistochemical and ultrastructural analysis.
The distribution of gap junctions within the vestibular labyrinth was investigated using immunohistochemistry and transmission electron microscopy. Connexin26-like immunoreactivity was observed amongExpand
Differentiation of inner ear fibrocytes according to their ion transport related activity
Findings point to cooperativity in fluid and ion transport between epithelial cells and neighboring fibrocytes and demonstrate functional diversity of fibracytes of the inner ear providing a basis for classifying those in the spiral ligament. Expand
Connexin 26 mutations in hereditary non-syndromic sensorineural deafness
To the authors' knowledge, this is the first nonsyndromic sensorineural autosomal deafness susceptibility gene to be identified, which implicates Cx26 as an important component of the human cochlea. Expand
Comparison of ion transport mechanisms between vestibular dark cells and strial marginal cells
Evidence is collected that ion transport mechanisms and their regulation are similar in vestibular dark and strial marginal cells and the present review compiles evidence in support of this hypothesis. Expand
Immunohistochemical Localization of the Na-K-Cl Co-transporter (NKCC1) in the Gerbil Inner Ear
The co-expression of NKCC1 and Na,K-ATPase in highly specialized subpopulations of cochlear and vestibular fibrocytes provides further evidence for their role in recycling K+ leaked or effluxed through hair cells into perilymph back to endolymph, as postulated in current models of inner ear ion homeostasis. Expand
Connexin-26 mutations in sporadic and inherited sensorineural deafness
Mutations in the GJB2 gene are a major cause of inherited and apparently sporadic congenital deafness and 35delG is the most common mutation for sensorineural deafness, which should facilitate diagnosis and counselling for the mostcommon genetic form of deafness. Expand