Pathological changes in stria vascularis and normal position of Reissner's membrane.

<p><b><i>A,B</i></b> In semi-thin sections (P28), the position of Reissner's membrane is not changed (bold arrow). Hair cells and supporting cells of the most basal turn have degenerated (open arrow). The neural dendrites in Rosenthal's canal appeared reduced (arrow). Scale bar: 100 µm. <b><i>C</i></b> and <b><i>D</i></b> are expanded views of the areas framed in <b><i>A</i></b> and <b><i>B</i></b> and display similar morphology of fibrocytes in mutants and controls. Scale bar 20 µm. By transmission electron microscopy (P28, <b><i>E–I</i></b>), the normal scallop-shaped (bold arrow) luminal boundary of marginal cells in control mice (<b><i>E</i></b>) was not found in the <i>Spns2^tm1a/tm1a</i> mice (<b><i>F</i></b>). Abnormalities were seen in nuclei of endothelial cells (EC) and pericytes (PC) in strial capillaries of <i>Spns2^tm1a/tm1a</i> mice (<b><i>G,H</i></b>), which were not seen in the capillaries of spiral ligament (<b><i>I</i></b>) and control strial capillaries (<b><i>E</i></b>). Scale bars: 10 µm in <b><i>E,F</i></b>, 2 µm in <b><i>G–I</i></b>.