P2RX2 and P2RX4 receptors mediate cation absorption in transitional cells and supporting cells of the utricular macula.

Purinergic receptors protect the cochlea during high-intensity stimulation by providing a parallel shunt pathway through non-sensory neighboring epithelial cells for cation absorption. So far, there is no direct functional evidence for the presence and type/subunit of purinergic receptors in the utricle of the vestibular labyrinth. The goal of the present study was to investigate which purinergic receptors are expressed and carry cation-absorption currents in the utricular transitional cells and macula.

Gene therapy for hereditary hearing loss by SLC26A4 mutations in mice reveals distinct functional roles of pendrin in normal hearing.

: Mutations of that abrogate pendrin, expressed in endolymphatic sac, cochlea and vestibule, are known to cause autosomal recessive sensorineural hearing loss with enlargement of the membranous labyrinth. This is the first study to demonstrate the feasibility of gene therapy for pendrin-related hearing loss. We used a recombinant viral vector to transfect cDNA into embryonic day 12.

Tmc2 expression partially restores auditory function in a mouse model of DFNB7/B11 deafness caused by loss of Tmc1 function.

Mouse Tmc1 and Tmc2 are required for sensory transduction in cochlear and vestibular hair cells. Homozygous Tmc1 mice are deaf, Tmc2 mice have normal hearing, and double homozygous Tmc1; Tmc2 mice have deafness and profound vestibular dysfunction. These phenotypes are consistent with their different spatiotemporal expression patterns.

Claudin expression during early postnatal development of the murine cochlea.

Background: Claudins are major components of tight junctions, which form the paracellular barrier between the cochlear luminal and abluminal fluid compartments that supports the large transepithelial voltage difference and the large concentration differences of K, Na and Ca needed for normal cochlear function. Claudins are a family of more than 20 subtypes, but our knowledge about expression and localization of each subtype in the cochlea is limited.

Results: We examined by quantitative RT-PCR the expression of the mRNA of 24 claudin isoforms in mouse cochlea during postnatal development and localized the expression in separated fractions of the cochlea.

Molecular architecture underlying fluid absorption by the developing inner ear.

Mutations of are a common cause of hearing loss associated with enlargement of the endolymphatic sac (EES). expression in the developing mouse endolymphatic sac is required for acquisition of normal inner ear structure and function. Here, we show that the mouse endolymphatic sac absorbs fluid in an SLC26A4-dependent fashion.