In vivo auditory nerve stimulation with visible light

Journal of Innovative Optical Health Sciences

Yonghong He¹  Tian Guan¹  Muqun Yang² 

[1] Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, P. R. China;Tsinghua-Berkeley Shenzhen Institute, Tsinghua University, Shenzhen 518055, P. R. China;

关键词: Pulsed laser;    optical stimulation;    cochlear implant;    optical compound action potentials;   

DOI  :  10.1142/S1793545817430040

来源: DOAJ

【 摘 要 】

Background: Infrared laser stimulation has been proposed as an innovative method to elicit an auditory nerve response. Most studies have focused on using long-wavelength infrared (>980nm) pulsed lasers with high water absorption coefficients. This paper sought to assess whether a short-wavelength laser (465nm) with an absorption coefficient as low as 10−3cm−1 would activate the auditory nerve and studied its potential mechanism. Method: Optical compound action potentials (OCAPs) were recorded when synchronous trigger laser pulses stimulate the cochlea before and after deafening, varying the pulse durations (from 800μs to 3600μs) and the amount of radiant energy (from 18.05mJ/cm2 to 107.91mJ/cm2). A thermal infrared imager was applied to monitor the temperature change of the guinea pig cochlea. Results: The results showed that pulsed laser stimulation at 465nm could invoke OCAPs and had a similar waveform compared to the acoustical compound action potentials. The amplitude of OCAPs had a positive correlation with the increasing laser peak power, while the latency of OCAPs showed a negative correlation. The imager data showed that the temperature in the cochlea rose quickly by about 0.3∘C right after stimulating the cochlea and decreased quickly back to the initial temperature as the stimulation ended. Conclusions: This paper demonstrates that 465-nm laser stimulation can successfully induce OCAPs outside the cochlea, and that the amplitude and latency of the invoked OCAPs are highly affected by laser peak power. This paper proposes that a photothermal effect might be the main mechanism for the auditory nerve response induced by short-wavelength laser stimulation.

【 授权许可】

Unknown