Spotlights

[Research News] Non-Invasive Optical Stimulation for Induction of Auditory Perception

Hearing loss affects communication, learning, independence, and social well-being. While cochlear implants have transformed treatment for severe hearing impairment, they require surgery and are often associated with post-operative complications. They also rely on electrical stimulation, which can limit their precision. Researchers are therefore exploring whether applying optical neural stimulation through brain-machine interfaces can mitigate these limitations. However, the effect of laser stimulation applied through the tympanic membrane is largely understudied.A research team led by Prof. Kohta I. Kobayasi of the Faculty of Life and Medical Sciences and Dr. Yuta Tamai of the Acoustic Navigation Research Center, Doshisha University, demonstrated for the first time that trans-tympanic infrared laser stimulation of the cochlea evokes reliable auditory-guided behaviour in awake Mongolian gerbils without the need for genetic modification or invasive surgical implantation.

Reference

Yuta Tamai, Miku Uenaka, Aya Okamoto, Yuki Ito, Kaito Fukada, Ayase Kawasaki, Takaki Shintani, Riko Nakagawa, Koji Toda, Shizuko Hiryu, Kohta I. Kobayasi, Optical induction of auditory perception via cochlear stimulation in Mongolian gerbils without genetic modification,iScience, 2026 
https://doi.org/10.1016/j.isci.2026.116588

This achievement has also been featured in “EurekAlert!”
https://www.eurekalert.org/news-releases/1136516

Image title: Trans-tympanic Infrared Laser Stimulation Evokes Auditory-Like Perception in Mongolian Gerbils 
Image caption: Top: Gerbils learned that both sound (blue) and laser stimulation (red) predicted a water reward, with similar learning curves. Middle: Loud background noise weakened responses driven by both sound (blue) and laser stimulation (red), suggesting that the laser signal was linked to hearing. Bottom: Gerbils trained with sound also responded to laser stimulation, suggesting that laser stimulation created a sound-like sensation.
Image credit: Dr. Yuta Tamai and Professor Kohta I. Kobayasi from Doshisha University, Japan 
Image source link: https://www.cell.com/iscience/fulltext/S2589-0042(26)01963-2?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2589004226019632%3Fshowall%3Dtrue
License type: CC BY 4.0
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