Zebrafish discovery throws new light on human hearing disorders

A study of the genetic make-up of zebrafish has provided brand new insights into the cause of congenital hearing disorders in humans. A team including scientists from Cardiff University has identified how specific genes can dictate the patterns of the tiny cells - so-called hair cells - within our ears that allow us to hear and process sounds. Genetic factors are thought to cause more than 50 per cent of all incidents of congenital hearing loss, with many attributed to the misalignment or damage of tiny hair cells. These hair cells exist in their thousands within the cochlea and are 'tuned' to respond to different sounds based on pitch or frequency. This is due to a collective property called 'planar polarization', or the orientation in which the tiny hairs are laid out. When sound enters the ear, the hairs change the sound vibrations into an electrical signal that is sent to the brain, allowing us to recognise it. Using zebrafish as a proxy, scientists have shed light on how changes to specific genes alter the coordinated direction that these cells are laid out.