Cochlear implantation in the mouse via the round window: effects of array insertion

Area of Science:

• Otorhinolaryngology
• Biomedical Engineering
• Auditory Neuroscience

Background:

• Animal models are crucial for studying cochlear implantation (CI) at cellular and molecular levels.
• Mouse models of deafness offer opportunities for auditory research, but CI studies in mice are limited.
• Developing a reliable mouse model for CI is essential for advancing auditory research.

Purpose of the Study:

• To establish a reproducible and viable technique for long-term cochlear implantation (CI) in mice.
• To evaluate the mouse cochlea's response to electrode array implantation.
• To assess the feasibility of using mice as a model for studying CI outcomes.

Main Methods:

• Electrode array implantation via the round window in C57Bl/6 mice (3 and 6 months old).
• Auditory brainstem response (ABR) recordings before and after CI.
• Cone beam computed tomography (CBCT) and light microscopy for electrode placement verification.
• Histological examination of cochleae to assess tissue response.

Main Results:

• Surgical technique demonstrated feasibility with correct electrode placement in the scala tympani.
• Auditory brainstem response (ABR) showed threshold shifts in the implanted ear, with significant hearing preservation.
• Histological analysis indicated tissue encapsulation and fibrosis around the implant.

Conclusions:

• Round window cochlear implantation (CI) in mice provides a reproducible model for auditory research.
• This model allows for the investigation of cellular and molecular responses to CI.
• Further research can utilize this model to explore tissue reactions and optimize CI strategies.