Cochlear implant imaging in the mouse and guinea pig using light-sheet microscopy

Area of Science:

• Otoacoustic emissions
• Neuroscience
• Biomedical engineering

Background:

• Postmortem examination of cochleas with cochlear implants presents significant technical challenges.
• The metallic components of cochlear implants damage traditional microtome blades, hindering histological sectioning.
• Previous methods include specialized sectioning of plastic-embedded cochleas.

Purpose of the Study:

• To describe a non-destructive method for optically sectioning chemically cleared cochleas using light-sheet microscopy.
• To evaluate the utility of light-sheet microscopy for examining implanted cochleas.
• To identify limitations and optimal conditions for imaging implanted cochleas.

Main Methods:

• Chemical clearing of postmortem cochleas.
• Optical sectioning using light-sheet microscopy.
• Comparison of imaging with and without the cochlear implant in situ.

Main Results:

• Light-sheet microscopy provides an alternative to physical sectioning for implanted cochleas.
• Opaque and reflective implant components cause artifacts in 2D optical sections.
• Optimal image quality is achieved when the cochlear implant is removed before imaging.

Conclusions:

• Light-sheet microscopy is a viable non-destructive technique for postmortem cochlear analysis.
• Careful consideration of implant artifacts is necessary when interpreting light-sheet microscopy data.
• Implant removal prior to imaging is recommended for the highest fidelity results in light-sheet fluorescent microscopy.