Simultaneous rather than retrograde spiral ganglion cell degeneration following ototoxically induced hair cell loss in the guinea pig cochlea.

Simultaneous rather than retrograde spiral ganglion cell degeneration following ototoxically induced hair cell loss in the guinea pig cochlea. Hear Res. 2020 Feb 24;390:107928 Authors: Ramekers D, Klis SFL, Versnel H Abstract Severe damage to the organ of Corti leads to degeneration of the spiral ganglion cells (SGCs) which form the auditory nerve. This degeneration starts at the level of synaptic connection of the peripheral processes (PPs) of SGCs with the cochlear hair cells. It is generally thought that from this point SGC degeneration progresses in a retrograde fashion: PPs degenerate first, followed by the SGC soma with a delay of several weeks to many months. Evidence for this course of events, both in animals and in humans, is not unambiguous, while this knowledge is important since the presence or absence of the different neural elements may greatly influence the response to electrical stimulation with a cochlear implant (CI). We therefore aimed to provide a comprehensive account of the course of SGC degeneration in the guinea pig cochlea after ototoxic treatment. Histological analysis of eighteen healthy and thirty-three deafened cochleas showed that the degeneration of SGCs and their peripheral processes was simultaneous rather than sequential. As the site of excitation for electrical stimulation with a CI may depend on the course of degeneration of the various neural elements, this finding is relevant both for understandi...
Source: Hearing Research - Category: Audiology Authors: Tags: Hear Res Source Type: research