Comparative Three-Dimensional Fine Structures of the Maculae Flavae of the Rat Vocal Fold Using the Correlative Light and Electron Microscopy.

Abstract

Objectives: The comparative fine structures of the maculae flavae of the rat vocal fold (VF) were investigated using the correlative light and electron microscopy (CLEM) technique combined with transmission electron microscopy (TEM).

Methods: Seven normal adult Sprague-Dawley rats were examined using the CLEM technique and TEM to investigate their fine structures.

Results: Cobblestone-like polygonal cells (CPCs), vocal fold stellate cell-like cells (VFSCs), and fibroblast-like spindle cells (FSCs) were identified in the anterior and posterior maculae flavae of the rat VF under CLEM and TEM. The VFSCs had lipid droplets in their cytoplasm under TEM. Microfibrils, collagen fibrils, and amorphous material were observed surrounding the periphery of the cytoplasm of the VFSCs, indicating that they synthesize extracellular matrices. Cell aggregations with CPCs were identified in the maculae flavae, indicating there is a complex cross-talk between the adhesion machinery and chemical signaling pathways.

Conclusion: The comparative fine structures of the cells in the maculae flavae suggested heterogeneity among the cells in the maculae flavae of the rat VF. The cellular components in the maculae flavae of the rat vocal folds (VFs) are similar to those in human maculae flavae, suggesting that rat VFs serve as a suitable model for animal experiment studies. The CLEM technique combined with TEM is a valuable tool for evaluating the fine structures of the VFs in small species and holds promise for future applications in animal studies of VF morphology and function.

Level of evidence: NA.