Detailed Morphology and Distribution of Gap Junction Protein Associated with Cells from the Intra-Articular Disc of the Rat Temporomandibular Joint

Abstract

The present study details structural aspects of the cells of the rat intra-articular disc (IAD) of the temporomandibular joint. At the light and electron microscope level, the outline of the cells varied, although a number appeared oval/rounded. Ultrastructurally, the cells contained moderate amounts of the intracellular organelles associated with protein synthesis. Cell processes were not a prominent feature seen using these techniques. However, using confocal microscopy, phalloidin staining revealed the presence of numerous, actin-rich, long, thin, branching processes emanating from the cell membranes. Double staining for connexin 43 revealed that the cell processes showed dense, punctate positive staining for this gap junction protein along their whole length. These observations provide the basis for a transport mechanism for nutritive molecules from the periphery of the IAD (where blood vessels are present) to the central portions of the disc (where blood vessels are absent).

• Confocal Microscopy
• Fibroblasts
• Gap Junctions
• Meniscus
• Ultrastructure