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An Isolated Semi-intact Preparation of the Mouse Vestibular Sensory Epithelium for Electrophysiology and High-resolution Two-photon Microscopy
Published on: June 13, 2013
Gap junction systems in the rat vestibular labyrinth: immunohistochemical and ultrastructural analysis
T Kikuchi1, J C Adams, D L Paul
1Department of Otolaryngology, Harvard Medical School, Boston, Massachusetts.
Insights
This study maps gap junctions in the vestibular system. Supporting cells form an epithelial network, while fibrocytes and melanocytes create a continuous connective tissue network.
Area of Science:
- Neuroscience
- Cell Biology
- Otolaryngology
Background:
- Gap junctions are crucial for intercellular communication.
- Their distribution in the vestibular labyrinth is not fully understood.
Purpose of the Study:
- To investigate the distribution and network formation of gap junctions in the vestibular labyrinth.
- To identify cell types involved in vestibular gap junction systems.
Main Methods:
- Immunohistochemistry using connexin26 antibody.
- Transmission electron microscopy for ultrastructural analysis.
Main Results:
- Connexin26-like immunoreactivity found in vestibular supporting cells, transitional epithelium, and planum semilunatum.
- No immunoreactivity in vestibular dark cells or thin wall epithelial cells.
- Fibrocytes and melanocytes show gap junctions, forming a continuous connective tissue network with the cochlea.
Conclusions:
- Two distinct gap junction systems exist in the vestibular system: an epithelial system and a connective tissue system.
- These networks may play significant roles in vestibular function and homeostasis.
Abstract:
The distribution of gap junctions within the vestibular labyrinth was investigated using immunohistochemistry and transmission electron microscopy. Connexin26-like immunoreactivity was observed among supporting cells in each vestibular sensory epithelium. Reaction product was also present in the transitional epithelium of each vestibular endorgan and in the planum semilunatum of crista ampullaris. No connexin26-like immunoreactivity was observed among thin wall epithelial cells or among vestibular dark cells. In addition, fibrocytes within vestibular connective tissue were positively immunostained. Reaction product was also detected in the melanocyte area just beneath dark cells. Ultrastructural observations indicated that a gap junction network of vestibular supporting cells extends to the transitional epithelium and planum semilunatum and forms an isolated epithelial cell gap junction system in each vestibular endorgan. In contrast, no gap junctions were found among wall epithelial cells or among dark cells. Fibrocytes and melanocytes were coupled by gap junctions and belong to the connective tissue cell gap junction system, which is continuous throughout the vestibular system and the cochlea. The possible functional significance of these gap junction systems is discussed.
