Radixin modulates stereocilia function and contributes to cochlear amplification [article]

Sonal Prasad, Barbara Vona, Marta Diñeiro Soto, María Costales, Rocío González-Aguado, Ana M Romero Fontalba, Clara Diego-Pérez, Asli Subasioglu, Guney Bademci, Mustafa Tekin, Rubén Cabanillas, Juan Cadiñanos (+1 others)
2020 bioRxiv   pre-print
The stereocilia of the sensory cells in the inner ear contain high levels of the actin-binding protein radixin, encoded by the RDX gene. Radixin which is associated with mechanotransduction process such as PIP2 is known to be important for hearing but its functional role remains obscure. To determine how radixin influences hearing sensitivity, we used a custom rapid imaging technique to directly visualize stereocilia motion while measuring the amplitude of the electrical potentials produced by
more » ... ntials produced by sensory cells during acoustic stimulation. Experiments were performed in guinea pigs, where upon blocking radixin, a large decrease in sound-evoked electrical potentials occurred. Despite this decrease other important functional measures, such as electrically induced sensory cell motility and the sound-evoked deflections of stereocilia, showed a minor amplitude increase. This unique set of functional properties alterations demonstrate that radixin is necessary to ensure that the inner ear converts sound into electrical signals at acoustic rates. Radixin is therefore a necessary and important component of the cochlear amplifier, the energy-consuming process that boosts hearing sensitivity by up to 60 dB.
doi:10.1101/2020.02.11.944355 fatcat:qol4vs2w7narpex6uoowvbevlq