# Hyperosmotic Sisomicin Infusion: A Mouse Model for Hearing Loss

## TL;DR

A new mouse model for hearing loss was developed using a hyperosmotic sisomicin infusion, causing rapid and consistent damage to cochlear hair cells.

## Contribution

A novel surgical method for inducing synchronized outer hair cell death in mice with high consistency.

## Key findings

- Hyperosmotic sisomicin infusion caused rapid outer hair cell death within 14 hours.
- Inner hair cells remained intact for three days before deteriorating by day seven.
- The model enables consistent ototoxic damage for studying hearing loss and regenerative therapies.

## Abstract

Hearing impairment arises from the loss of either type of cochlear sensory hair cells. Inner hair cells act as primary sound transducers, while outer hair cells enhance sound-induced vibrations within the organ of Corti. Established models, such as systemic administration of ototoxic aminoglycosides, yield inconsistent and variable hair cell death in mice. Overcoming this limitation, we developed a method involving surgical delivery of a hyperosmotic sisomicin solution into the posterior semicircular canal of adult mice. This procedure induced rapid and synchronous apoptotic demise of outer hair cells within 14 hours, leading to irreversible hearing loss. The combination of sisomicin and hyperosmotic stress caused consistent and synergistic ototoxic damage. Inner hair cells remained intact until three days post-treatment, after which deterioration in structure and number was observed, culminating in cell loss by day seven. This robust animal model provides a valuable tool for otoregenerative research, facilitating single-cell and omics-based studies toward exploring preclinical therapeutic strategies.