Related Experiment Video
Updated: Sep 23, 2026
Dissection of the Endolymphatic Sac from Mice
Published on: March 29, 2021
Vestibular morphology in the mutant mix-mouse
Harushiro Sato1, Dan Bagger-Sjöbäck, Malou Hultcrantz
1Institute for Hearing and Communication Research, Karolinska Institutet, Karolinska Hospital, Stockholm, Sweden. haruent@hotmail.com
Abstract:
Mix-mice, a new strain of mice with inner ear dysfunction, and their littermates were used in the present study in order to investigate vestibular morphology, visualised by light microscopy (LM) and transmission electron microscopy (TEM). Contrary to the mix-mice, their littermates showed less stained nerve chalices and it was possible to detect that hair cells showed surface herniations and so-called 'blebs' in the apical portion of the epithelium. Sensory hairs showed a disarrayed pattern. The mix-mice had severe microscopical abnormalities: collapse of the membranous cell layer, cavities inside the neuroepithelium, severe loss of hair cells, herniations of the few remaining hair cells and increased supporting cells were evident. In the utricle and saccule, hair cells were missing and the epithelial surface was covered by a single layer of smooth, flattened epithelial cells of hitherto unknown origin.
Insights
Mix-mice exhibit severe inner ear abnormalities, including hair cell loss and epithelial collapse. Their littermates show milder hair cell defects, indicating distinct vestibular morphology differences.
Area of Science:
- Vestibular system morphology
- Inner ear dysfunction research
- Comparative microscopy
Background:
- Inner ear dysfunction can lead to balance and hearing issues.
- Understanding the cellular basis of vestibular disorders is crucial for developing treatments.
- The mix-mouse strain presents a novel model for studying genetic inner ear abnormalities.
Purpose of the Study:
- To investigate and compare the vestibular morphology of mix-mice and their littermates.
- To identify specific cellular and structural differences associated with inner ear dysfunction in mix-mice.
- To utilize light microscopy (LM) and transmission electron microscopy (TEM) for detailed ultrastructural analysis.
Main Methods:
- Comparative analysis of vestibular tissues from mix-mice and control littermates.
- Light microscopy (LM) for visualizing overall tissue structure.
- Transmission electron microscopy (TEM) for high-resolution ultrastructural examination of hair cells and epithelial layers.
Main Results:
- Mix-mice displayed severe abnormalities: membranous layer collapse, neuroepithelial cavities, significant hair cell loss, and herniations.
- Control littermates showed fewer stained nerve chalices and exhibited hair cell surface herniations and apical blebs.
- Sensory hairs in littermates were disorganized; mix-mice utricles and saccules lacked hair cells, replaced by flattened epithelial cells.
Conclusions:
- Mix-mice possess distinct and severe inner ear morphological defects compared to their littermates.
- The observed abnormalities in mix-mice suggest a profound disruption of vestibular sensory epithelium development and maintenance.
- Further research into the genetic basis of these abnormalities in mix-mice is warranted.
