# Optimizing Factors in Murine Whole-Organ Cochlea Culture

## TL;DR

Researchers optimized a method to culture cochleae from 10-day-old mice, preserving all cell types using neurotrophins and mild hypothermia.

## Contribution

The study introduces neurotrophins and mild hypothermia to extend cochlea culture methods to older mice.

## Key findings

- Adding Bdnf and Ntf3 to the culture medium ensures survival of all cochlear cell types in 10-day-old mice.
- Culturing at 32 °C preserves cochlear cell viability and structure similar to in vivo conditions.
- The modified method allows successful 3D cochlea culture beyond early postnatal stages.

## Abstract

In 2008, Hahn et al. presented a method for cultivating a 3D organ culture of the cochlea. Although this method is well established, it is currently only applied to early postnatal animals. Given the known differences in regeneration and repair abilities between early postnatal and adult mammalian cochleae, our goal was to further develop and optimize this method to extend it beyond early postnatal animals to include adult mammalian cochleae. After rapidly dissecting the cochlea, it is opened and placed in a neurotrophin-containing culture medium. The culture is then maintained at 32 °C in a rotating bioreactor for 24 h. The combination of mild hypothermia (32 °C), quick cochlea dissection, and the addition of 10 ng/mL of Brain-derived neurotrophic factor (Bdnf) and 5 ng/mL of Neurotrophin 3 (Ntf3) to the culture medium ensures the complete cell survival of all cochlear cell types in 10-day-old mice. The modifications to the established method include the incorporation of neurotrophins (Bdnf and Ntf3) into the culture medium and cultivation under mild hypothermic conditions (32 °C). By introducing neurotrophins and cultivating at 32 °C, a 3D organ culture of the cochlea can also be established with 10-day-old mice. This in vitro model preserves all cochlear cell types under conditions similar to those found in vivo.