These filaments then extend in a belt like array of all along the top of the cell. What is the adhesion protein at this junction. Thick fibers loop into a junctional region and the cytoplasm. The next junction in the series is the Gap junction. Recall from Cell Biology that the Gap junction allow cells to communicate with one another.
Small molecules can pass through pore-like transmembrane proteins called connexons.
The following photograph shows this diagrammatically. Note that ions, molecules like fluorescein, and second messengers can pass from cell to cell. The following photograph shows the gap junctions prepared three different ways. Recall that negative staining is the deposition of heavy metal around a structure that is floated on a water surface. The photo on the left shows the donut shape of the connexon molecules.