Researchers studied the lateral stripes on zebra fish. These stripes contain sensing cells which allow the fish to sense its surroundings and have recently been known to have much in common with the human inner ear cells, and unlike human or mouse hearing cells, the sensing cells on zebra fish are accessible and easy to study.
The study discovered that the Tmie protein, or transmembrane inner ear protein, has a crucial role in our ability to hear.
Scientists observed profound hearing loss and balance disorders in a group a zebra fish. Morphologically, no difference was found when compared to fish with normal hearing ability. The cause of their hearing loss was exclusively found in a mutation of the gene encoding the Tmie protein.
The cells in the inner ear transform the sound stimuli into electrical signals which travel throughout the neurons to be processed by the brain. This transduction process, from stimuli to electrical signals, is carried out thanks to some proteins. In the case of the Tmie protein, this protein crosses the cellular membrane and controls the mechanotransduction ability of the hearing cell, explained the researchers. When there is a mutation which affects the protein the process cannot be appropriately completed.
Suggests a new approach
This research suggests a new approach to the study of profound hearing loss in humans, since it has been found that damage in the Tmie protein causes hearing problems and balance disorders both in humans and mice.
“This study will provide us with a lot of useful information to detect and develop new methods to treat hearing loss and balance disorders in humans in the future,” states Hernán López-Schier, head of the research team.
About the study
The research was carried out by the Genomic regulation center in Barcelona, Spain in cooperation with researchers from the Howard Hughes Institute and Rockefeller University in US. The conclusions were published in the scientific journal Proceedings of the National Academy of Sciences.