RT Journal Article
SR Electronic
T1 Watching Death in the Gerbil Cochlea Using Optical Coherence Tomography
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.04.29.442005
DO 10.1101/2021.04.29.442005
A1 Nam Hyun Cho
A1 Haobing Wang
A1 Sunil Puria
YR 2021
UL http://biorxiv.org/content/early/2021/04/30/2021.04.29.442005.abstract
AB Because it is difficult to directly observe the morphology of the living cochlea, our ability to infer the mechanical functioning of the living ear has been limited. Nearly all of our knowledge about cochlear morphology comes from postmortem tissue that was fixed and processed using procedures that possibly distort the structures and fluid spaces of the organ of Corti. In this study, optical coherence tomography was employed to obtain in vivo and postmortem micron-scale volumetric images of the high-frequency hook region of the gerbil cochlea through the round-window membrane. The anatomical structures and fluid spaces of the organ of Corti were segmented and quantified in vivo and over a 90-minute postmortem period. The results show that some aspects of the organ of Corti are significantly altered over the course of death, such as the volumes of the fluid spaces, whereas the dimensions of other features change very little. We postulate that the fluid space of the outer tunnel and its surrounding tectal cells form a resonant structure that can affect the motion of the reticular lamina and thereby have a profound effect on outer-hair-cell transduction and thus cochlear amplification. In addition, the in vivo fluid pressure of the inner spiral sulcus is postulated to effectively inflate the connected sub-tectorial gap between the tectorial membrane and the reticular lamina. This gap height decreases after death, which is hypothesized to reduce and disrupt hair-cell transductionCompeting Interest StatementThe authors have declared no competing interest.