Journal article

Infrared neural stimulation fails to evoke neural activity in the deaf guinea pig cochlea

Alexander C Thompson, James B Fallon, Andrew K Wise, Scott A Wade, Robert K Shepherd, Paul R Stoddart



At present there is some debate as to the processes by which infrared neural stimulation (INS) activates neurons in the cochlea, as the lasers used for INS can potentially generate a range of secondary stimuli e.g. an acoustic stimulus is produced when the light is absorbed by water. To clarify whether INS in the cochlea requires functioning hair cells and to explore the potential relevance to cochlear implants, experiments using INS were performed in the cochleae of both normal hearing and profoundly deaf guinea pigs. A response to laser stimulation was readily evoked in normal hearing cochlea. However, no response was evoked in any profoundly deaf cochleae, for either acute or chronic deaf..

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Awarded by Australian Research Council

Funding Acknowledgements

The authors thank C.-P. Richter of Northwestern University for the loan of the Aculight laser and helpful discussions. S. Irving of the Bionics Institute kindly assisted with aspects of the in vivo experiments. This work was supported by Cochlear Ltd and the Australian Research Council under grant LP120100264. The Bionics Institute acknowledges the financial support it receives from the Victorian State Government.