Scanning laser optical tomography for in toto imaging of the murine cochlea

PLoS One. 2017 Apr 7;12(4):e0175431. doi: 10.1371/journal.pone.0175431. eCollection 2017.

Abstract

The mammalian cochlea is a complex macroscopic structure due to its helical shape and the microscopic arrangements of the individual layers of cells. To improve the outcomes of hearing restoration in deaf patients, it is important to understand the anatomic structure and composition of the cochlea ex vivo. Hitherto, only one histological technique based on confocal laser scanning microscopy and optical clearing has been developed for in toto optical imaging of the murine cochlea. However, with a growing size of the specimen, e.g., human cochlea, this technique reaches its limitations. Here, we demonstrate scanning laser optical tomography (SLOT) as a valuable imaging technique to visualize the murine cochlea in toto without any physical slicing. This technique can also be applied in larger specimens up to cm3 such as the human cochlea. Furthermore, immunolabeling allows visualization of inner hair cells (otoferlin) or spiral ganglion cells (neurofilament) within the whole cochlea. After image reconstruction, the 3D dataset was used for digital segmentation of the labeled region. As a result, quantitative analysis of position, length and curvature of the labeled region was possible. This is of high interest in order to understand the interaction of cochlear implants (CI) and cells in more detail.

MeSH terms

  • Animals
  • Cochlea / diagnostic imaging*
  • Mice
  • Tomography, Optical / methods*

Grants and funding

This work was supported by the DFG Cluster of Excellence EXC 1077/1 "Hearing4all" (http://hearing4all.eu/) and the Ministry of Lower Saxony and the VolkswagenStiftung (both BIOFABRICATION FOR NIFE: VWZN2860, http://biofabrication.info/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.