Optical path of infrared neural stimulation in the guinea pig and cat cochlea

Suhrud M. Rajguru, Margaret Hwang, Laura E. Moreno, Agnella I. Matic, Stuart R. Stock, Claus Peter Richter

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations


It has been demonstrated previously that infrared neural stimulation (INS) can be used to stimulate spiral ganglion cells in the cochlea. With INS, neural stimulation can be achieved without direct contact of the radiation source and the tissue and is spatially well resolved. The presence of fluids or bone between the target structure and the radiation source may lead to absorption or scattering of the radiation and limit the efficacy of INS. To develop INS based cochlear implants, it is critical to determine the beam path of the radiation in the cochlea. In the present study, we utilized noninvasive X-ray microtomography (microCT) to visualize the orientation and location of the optical fiber within the guinea pig and cat cochlea. Overall, the results indicated that the optical fiber was directed towards the spiral ganglion cells in the cochlea and not the nerve fibers in the center of the modiolus. The fiber was approximately 300 μm away from the target structures. In future studies, results from the microCT will be correlated with physiology obtained from recordings in the midbrain.

Original languageEnglish (US)
Title of host publicationPhotonic Therapeutics and Diagnostics VII
StatePublished - Apr 12 2011
Externally publishedYes
EventPhotonic Therapeutics and Diagnostics VII - San Francisco, CA, United States
Duration: Jan 22 2011Jan 24 2011

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


OtherPhotonic Therapeutics and Diagnostics VII
Country/TerritoryUnited States
CitySan Francisco, CA


  • auditory
  • cat
  • cochlea
  • cochlear implants
  • deafness
  • guinea pig
  • Infrared neural stimulation
  • laser

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Radiology Nuclear Medicine and imaging


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