Fig. 1

(A) The physiological structure of the inner ear up to the auditory central system. (B) Typical pathological changes of the SMA damaged by DM. (C) Typical pathological changes of the SV and VSV damaged by DM. (D) Typical pathological changes of the spiral ganglion damaged by DM. (E) A cross-section showing typical pathological changes of cochlear afferent nerve fibers damaged by DM. (F) Typical pathological changes of the OC damaged by DM

DM: diabetes mellitus; SMA: spiral modiolar artery; SV: stria vascularis; VSV: vessels of the stria vascularis; MCs: marginal cells; ICs: intermediate cells; BCs: basal cells; SL: spiral ligament; SGNs: spiral ganglion neurons; OC: organ of Corti; OHCs: outer hair cells; IHCs: inner hair cells; SCs: supporting cells