Figure 3

The accumulation of dextran-FITC fluorescence (40 kDa) in noise-traumatized organs of Corti. A, A schematic drawing showing the three structural zones in the reticular lamina: the inner zone, the middle zone, and the outer zone. Each zone has a unique set of intercellular junctions. BC: Border cells. IHC: Inner hair cells. PC: Pillar cells. OHC & OPC: Outer hair cells and outer pillar cells. OHC & DC: Outer hair cells and Deiters cells. DC: Deiters cell. HC: Hensen cells. B, Inner zone. To better illustrate the structure of the tissue, the image showing dextran-FITC fluorescence (green) is superimposed over the DIC view of the reticular lamina. Sporadic dextran-FITC fluorescence is present in the junctions between pillar cells and outer hair cells (arrows). C, Middle zone. Arrows indicate dextran-FITC fluorescence in the spaces between the hair cells and pillar cells. C1 and C2 on the right are the magnified views of the inset in C. The schematic plot between C1 and C2 illustrates the optical levels from which the images C1 and C2 were derived using confocal microscopy. C1 shows an absence of dextran-FITC fluorescence in the junctions between the outer hair cells and pillar cells (arrows) at the level of the reticular lamina. C2 shows the same region, but at a level that is a few microns beneath the reticular lamina, where the dextran-FITC fluorescence is present in the spaces between the outer hair cells and the pillar cells and between the outer hair cells and Deiters cells (arrows). D, Outer zone. The image shows the intercellular junctions between the Hensen cells (arrows) and between the Deiters cells (double-arrows). E, Weak fluorescence is present at the level of the Deiters cell bodies (arrows). Bar: 20 μm.