The spatial correlation between sensory cell damage and the intercellular accumulation of Dextran-FITC. A, The distribution of sensory cell damage and the retention of dextran-FITC fluorescence (40 kDa) at intercellular junctions along the organ of Corti following exposure to intense noise. The line plot illustrates the distribution of sensory cell damage, and the shaded bar represents the area showing an intercellular accumulation of dextran-FITC. The horizontal bars indicate the size and the location of dextran-FITC fluorescence in the organ of Corti. Each row of the bar(s) represents the data from a single cochlea. B, Double-staining of dextran-FITC (green fluorescence) and propidium iodide (red fluorescence) in a section of the organ of Corti following acoustic overstimulation. The arrows point to damaged outer hair cells exhibiting malformed nuclei with increased propidium iodide fluorescence. Bar: 25 μm. C, A region of the organ of Corti showing an intercellular accumulation of dextran-FITC fluorescence but without propidium iodide fluorescence. D, A typical image of dextran-FITC and propidium iodide double-staining in a control cochlea.