Three-Dimensional Distribution and Analysis of Gerbil Spiral Ganglion Cells

The cochlea converts physical sound waves into neural code transmitted through the auditory to the brain via spiral ganglion cells (SGCs). A better understanding of cochlear anatomy and physiology, particularly the three-dimensional anatomy and functions of different types and subtypes of SGCs, is necessary for improving cochlear implant technology, understanding sensorineural hearing loss and deafness, and other potential clinical methods to address hearing impairments (Stakhovskaya et. al, 2007). Light-sheet fluorescence microscopy (LSFM) was used to study SGCs in Mongolian gerbil (Meriones unguiculatus) cochleae with anatomical relationships preserved. Cochleae were immunofluorescence stained for type I; subtypes IA, IB, and IC; and type II SGCs, followed by counting and location analysis in Imaris software. We found a higher than previously stated average number of cells and a novel number of cells located outside of Rosenthal’s canal. Future work to characterize these cells would yield a better understanding of cochlear physiology, with the goal of improving and expanding treatment for hearing impairments.