Advective mass transport along the cochlear coil.

Mammalian auditory epithelium (the organ of Corti) stands out among different inner-ear epithelia in that it has large extracellular fluid spaces such as the tunnel of Corti, Nuel's space, outer tunnel, and spacing between outer hair cells. We tested the hypothesis that advective flow facilitates mass transport in the cochlear fluids, using computational simulations of cochlear fluid dynamics and ex vivo experiments to investigate mass transport in extracellular fluid spaces of the cochlea. Three model simulations were performed in series-cochlear mechanics, nonlinear fluid dynamics, and mass transport. In nonlinear fluid dynamics, we incorporated convection terms for more accurate computation of drift flow. For mass transport, both diffusion and advection were considered. For experiments, we measured vibrations of excised cochlear turns using optical coherence tomography. The excised OoC was subjected to acoustic and electrical stimulations.