Synthesis of glycocalyx and associated structures in vestibular sensory cells

Abstract

The ultrastructure of the glycocalyx with special reference to the synthesizing process was studied in the guinea pig vestibular sensory cells using the tannic acid staining technique. The glycocalyx emerged from the outer layer of the plasma membrane covering the entire length of the cilia. This glycocalyx also interconnected the ciliary structures tightly, such that a structural continuity was established between actin-membrane links and the glycocalyx. Interconnections between the actin filaments themselves were also noticed in the stereocilia as well as interconnections between individual actin filaments and the plasma membrane. These findings indicate that the glycocalyx and the ciliary interconnections may be closely related to the sensory hair transduction system. In the cellular cytoplasm, vesicles seemingly related to the synthesis of the glycocalyx were observed. These coated vesicles, which were synthesized by the Golgi complex and endoplasmic reticulum, interacted with the plasma membrane forming a coated pit. The lysosomal-like bodies also observed in the cell were closely related to the glycocalyx as well. Thus the glycocalyx seems to be synthesized by the endoplasmic reticulum and Golgi complexes and transferred through the coated vesicles or lysosomal-like bodies to the apical plasma membrane.