Fig. 5
mCherry reporter immunolabeling resolves subpopulations of cochlear spiral ganglion neurons (SGN) and vestibular ganglion neurons (VGN) in the intact adult mouse inner ear. Intact adult Prphp-mCherry mouse inner ear tissue cleared with CUBIC/PEGASOS, imaged using Zeiss Z1 Lightsheet microscopy, rendered and analyzed with Imaris (v.9.1). Distribution of mCherry + ve (red) SGN and VGN, with co-immunolabeling against peripherin (Prph, white). Prph is a marker for cochlear type II SGN (innervating outer hair cells), and VGN whose afferents terminate as boutons on type II hair cells. mCherry + ve SGN are biased to the base, particularly the hook region (highest frequency). In contrast, mCherry + ve VGN are broadly distributed across both the superior (SUP) and inferior (INF) regions. Prph + ve peripheral VGN neurites project to all vestibular end-organs (saccule (SA), utricle (UT), semicircular canals (anterior (AC), lateral (LC), posterior (PC)). Two large Prph + ve bipolar neurons of undetermined significance were located outside of Rosenthal’s canal in the cochlear modiolus (*). Geniculate ganglion neurons (GGN; facial nerve VII) reside above the VGN; most of the GGN in this sample were outside the volume rendering. This image has removed non-specific puncta with segmentation, to aid in visualization of elements of interest. A characteristic frequency map of the tonotopically-organized cochlea is shown.
