Modeling the spatial variations of the intracochlear fluid pressure based on in vivo mechanical measurements

The mammalian cochlea is a complex system consisting of two fluid-filled ducts separated by a structure known as the organ of Corti. Fluid pressure in the cochlear ducts interact with the organ of Corti to stimulate the mechanoelectrical receptors responsible for hearing. Because, until recently, in vivo dynamic measurements were limited to the basilar membrane, most cochlear models consider only basilar membrane—fluid interactions. Recent measurements of tectorial membrane and reticular lamina motions using optical coherence tomography motivate us to develop cochlear models that takes into account separately coupling of the fluid with all these components of the organ of Corti. In this work, finite element models are used to simulate an apical slice of a mouse cochlea. Using experimentally measured motion of the stapes, reticular lamina, basilar membrane, and tectorial membrane [Lee et al., J. Neurosci. (2016)] as input, spatial variations of pressure in the cochlea are explored. This study investigates fluid dynamics in the cochlear ducts and explores the relationship between the motion of the organ of Corti and spatial pressure variations while providing a basis for future computational models to consider cochlear fluid dynamics in the entire cochlea.