Age-dependent Shifts in Spiral Ganglion Neuron Subtypes Are Associated with Interphase Gap-dependent Modulation of Electrically Evoked Compound Action Potentials in Mice

Older adults with profound hearing loss can derive substantial benefit from cochlear implants (CIs), yet outcomes are more variable than in younger recipients. Degeneration of spiral ganglion neurons (SGNs) is a major determinant of CI performance, and age-related hearing loss (ARHL) is accompanied by subtype-specific SGN alterations....

No immediate practice change, but this preclinical mouse study suggests that age-related shifts in spiral ganglion neuron subtypes may partly explain variable cochlear implant outcomes in older recipients — a hypothesis that warrants follow-up in human studies.

Understanding how aging alters the neural substrate of electrical hearing could eventually guide age-tailored cochlear implant programming strategies to optimise outcomes in older patients.

1. 01Aging in mice causes measurable shifts in the distribution of spiral ganglion neuron (SGN) subtypes.
2. 02These SGN subtype changes correlate with altered electrically evoked compound action potentials (ECAPs).
3. 03Interphase gap manipulation of electrical stimuli revealed age-dependent differences in neural responses.
4. 04Findings are from a mouse model — direct translation to human cochlear implant patients requires further study.
5. 05Results may help explain why elderly cochlear implant users sometimes show different audiological outcomes.

PMID

42270924

DOI

10.1007/s10162-026-01059-7.

Journal

Journal of the Association for Research in Otolaryngology (JARO)

Publication type

research_article

Evidence level

4

Population

Mice of varying ages with assessed spiral ganglion neuron subtypes

Intervention

Electrically evoked compound action potentials with interphase gap manipulation across age groups

Comparator

Younger mice (age-matched controls)