Figure 8. Filipin-treated gap junctions. A: A representative cholesterol-rich gap junction with the presence of numerous filipin-cholesterol complexes (FCCs, small arrows) is frequently found in the outer cortical fibers. B and C: Cholesterol-intermediate gap junctions with less number of FCCs (small arrows) are observed in the inner cortical fibers. FCCs (small arrows) are often distributed along patches or parallel rows of crystalline-packed connexons (large arrows). D and E: Cholesterol-free gap junctions are mostly seen in the deeper mature cortical fibers. Note that crystalline-arranged connexons can be visualized more clearly on the E-face (ef) of the membrane. In the images, pf indicates the P-face of the membrane. The scale bars indicate 200 nm.