Strong Roots

We hear sounds thanks to specialist hair cells in our inner ear: vibrations bend microscopic hair-like stereocilia attached to these cells, triggering chemical changes and ultimately producing electrical signals, forwarded to the brain. Stereocilia are anchored to hair cells by rootlets, structures that support them so they can bend repeatedly without breaking. Using sophisticated imaging techniques, scientists recently identified an essential protein, known as spectrin, which encircles the rootlets, providing strength and flexibility. Without spectrin in their inner hair cells, mice have seriously impaired hearing. At the cellular level (pictured, in healthy inner hair cells above, and ones lacking spectrin below), the organisation of other crucial proteins is disrupted, including actin (in blue), of which stereocilia are made, and taperin (in purple). Mice with poor hearing due to ageing or sound damage also display depleted spectrin rings, suggesting that this protein is involved in many forms of hearing loss.

Written by Emmanuelle Briolat

Emmanuelle Briolat

Writer

A researcher specialising in visual signals in Lepidoptera, camouflage and the effects of light pollution, Emmanuelle’s writing covers a range of topics, from biomedical research to children’s books about moth defences.

Website

• Image adapted from work by Yan Liu, Jieyu Qi, Xin Chen and Mingliang Tang, and colleagues
• ShanghaiTech University, Shanghai, China
• Image originally published under a Creative Commons Licence (BY-NC 4.0)
• Published in Science Advances, April 2019