The major goal in this proposal is to develop an instrument to measure the vibration of the organ of Corti in the living guinea pig. The instrument will use the principles of optical coherence tomography (OCT) and low optical coherence interferometry to visualize the basilar membrane and the internal structures of the organ and to measure their vibratory displacements induced by sound stimulation of the ear, respectively. The OCT interferometer will utilize light from two different super luminescent diodes coupled into a common optical fiber, allowing simultaneous measurement of the vibratory displacement of the basilar membrane and the reticular lamina components of the organ of Corti. The first two aims of the proposal are 1) to develop a dual source (two channels) OCT interferometer for measurements at a single location in the organ and 2) to develop a scanning OCT interferometer to measure organ of Corti motion in three dimensions. OCT interferometry will have the advantage of not requiring any reflective objects (such as mirrors or beads) to be placed on the ear tissues and will have high optical spatial resolution (particularly in the 'z' direction along the optical axis) allowing accurate magnitude and phase measurements of organ of Corti tissue vibration.
The third aim i s to use the OCT instrument to measure the three-dimensional vibration pattern of the basilar membrane and reticular lamina in the guinea pig. The data will give critical new insight into the micro mechanical motion of the organ of Corti and on the mechanism of the cochlear amplification process whereby outer hair cells are thought to be actively enhancing organ of Corti motion.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC006273-02
Application #
6998876
Study Section
Auditory System Study Section (AUD)
Program Officer
Donahue, Amy
Project Start
2004-12-17
Project End
2007-11-30
Budget Start
2005-12-01
Budget End
2006-11-30
Support Year
2
Fiscal Year
2006
Total Cost
$192,455
Indirect Cost
Name
Oregon Health and Science University
Department
Otolaryngology
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239
Wu, T; Song, L; Shi, X et al. (2011) Effect of capsaicin on potassium conductance and electromotility of the guinea pig outer hair cell. Hear Res 272:117-24
Chen, Fangyi; Choudhury, Niloy; Zheng, Jiefu et al. (2007) In vivo imaging and low-coherence interferometry of organ of Corti vibration. J Biomed Opt 12:021006
Choudhury, Niloy; Song, Guiju; Chen, Fangyi et al. (2006) Low coherence interferometry of the cochlear partition. Hear Res 220:1-9