TRP channels as candidates for hearing and balance abnormalities in vertebrates.
In this review, we summarize the potential functional roles of transient receptor potential (TRP) channels in the vertebrate inner ear. The history of TRP channels in hearing and balance is characterized at great length by the hunt for the elusive transduction channel of sensory hair cells. Such pursuit has not resulted in unequivocal identification of the transduction channel, but nevertheless revealed a number of candidates, such as TRPV4, TRPN1, TRPA1, and TRPML3. Much of the circumstantial evidence indicates that these TRP channels potentially play significant roles in inner ear physiology. Based on mutations in the corresponding mouse genes, TRPV4 and TRPML3 are possible candidates for human hearing, and potentially also balance disorders. We further discuss the role of the invertebrate TRP channels Nanchung, Inactive, and TRPN1 and how the functional analysis of these channels provides a link to vertebrate hearing and balance. In summary, only a few TRP channels have been analyzed thus far for a prospective role in the inner ear, and this makes the search for additional TRPs associated with inner ear function quite a tantalizing endeavor.
Cuajungco
Math P
MP
Department of Otolaryngology, Head and Neck Surgery, Stanford University School of Medicine, 801 Welch Road, Stanford, CA 94305, USA.
Grimm
Christian
C
Heller
Stefan
S
D000818:Animals; D015220:Calcium Channels / Q000502:physiology; D006198:Hair Cells, Auditory / Q000502:physiology; D006309:Hearing / Q000502:physiology; D006311:Hearing Disorders / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D007448:Invertebrates / Q000502:physiology; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000502:physiology; D010802:Phylogeny; D004856:Postural Balance / Q000502:physiology*; D012678:Sensation Disorders / Q000209:etiology* / Q000503:physiopathology; D015398:Signal Transduction; D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels / Q000502:physiology*; D029961:Zebrafish Proteins / Q000502:physiology
D015220:Calcium Channels; C510642:MCOLN3 protein, human; D009419:Nerve Tissue Proteins; D000074025:TRPA1 Cation Channel; C473350:TRPA1 protein, human; D050051:Transient Receptor Potential Channels; D029961:Zebrafish Proteins; C475465:trpn1 protein, zebrafish