Development of spiral ganglion neurons as revealed with Mmp-24 in situ hybridization.
The metalloproteinase Mmp-24 is an early marker for sensory neurons of the ear (A–D) and also labels the organ of Corti at later stages (C, D). This marker reveals that developing spiral ganglion neurons are differently distributed inside the developing cochlea from E14.5 (A, B) to E18.5 (C, D): Instead of dispersing along the cochlea (A, C) neurons lump together in the center of the cochlea (B, D). Whereas spiral ganglion neurons are in control mice at a nearly constant distance from the cochlea (C’) all spiral ganglion neurons aggregate in the center of the basal turn in the Wnt1-cre;Sox10f/f littermates (D’). Abbreviations: OC, organ of Corti; PC, posterior crista; AC, anterior crista; HC, horizontal crista; U, utricle; S, saccule; SPG, spiral ganglion; VG, vestibular ganglion. Bar indicates 100 μm.
