Amelioration of cochlea with light waves is expected to benefit hearing impaired people

At present, there are about 500 thousand severely impaired people in the world, and one of the cochlear cochlear is the use of electronic devices to restore a bit of hearing. Led by Tobias Moser, a hearing neuroscientist at the German University of song Ting root, researchers will improve the light in the hope of breaking through the limitations of existing cochlear cochlear.

The cochlea is a spiral structure of the inner ear that can be used to analyze the frequency of the sound. The different frequencies in the speech cause the membrane of the cochlea to vibrate, and the vibrations will activate the cells similar to the "hair", stimulate the hearing neurons, and transmit the related information of the sound through the auditory nerve to the brain.

People with sensorineural deafness, because they lose hair like cells, stimulate neurons through the cochlear electrode. However, because the current produced by the electrode is not a straight line to the hearing neuron, it will be dispersed through the process, so if the electrode is too close, the crosstalk interference will occur. Therefore, the current cochlear cochlea limits the number of electrodes to avoid interference, but also limits the user's hearing performance.

The Moser team used optical genetics technology (Optogenetics) to replace the electrodes with light. Optical genetic technology is usually used in animal research, which stimulates genes to produce photosensitive proteins into neurons and stimulate neurons through light.

The research team took gerbil as the experimental object to transform the rat gene into a mouse, shorten the recovery time needed for the two activation of retina protein, then injected the bacteria into the gerbils cochlea, and then put the retina protein gene into the hearing neuron, and then use the optical fiber to enter the cochlea through the round window in the ear. The results were similar to those in the brain stem of gerbil that were responsible for hearing.

At present, the research team uses only one light wave, and the next step will develop a device that can produce multiple light waves. The device may be designed to use Micro LED array or waveguide technology to guide the light produced by optical fiber. Because the optical fiber will consume a lot of electricity, the device is expected to be very heavy. Daniel Lee, an ear doctor at Harvard Medical School, points out that LED is a better choice, but the light is relatively blurred, so it needs a breakthrough technology.

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