Figure 4.

Stria vascularis as a neutrophil-free region during cochlea inflammation. A three-dimensional image of cochlear lateral wall using two-photon intravital microscopy shows middle turn of the untreated cochlea (A), middle turn of the inflamed cochlea with middle ear inoculation with LPS 2 days before euthanization (B), basal turn of the untreated cochlea (C), and basal turn of the inflamed cochlea with LPS middle ear inoculation 2 days before euthanization (D). In each cochlea image, the X-Y plane is presented on the left side, and the Y-Z plane of the sagittal reconstructed image is presented on the right side. The region of the stria vascularis is marked with a dotted line. After sagittal reconstruction, neutrophils were quantified in the spiral ligament adjacent to the stria vascularis (~6000 µm²) (E) and in the stria vascularis (~6000 µm²) (F). Notably, neutrophils were absent in the stria vascularis at any time point. The contralateral cochlea was obtained from the mouse after intravital imaging performed after i.v. injection of Texas Red-dextran. The green region shows LysM-GFP positive cells. The red region shows blood vessels stained with Texas Red-dextran. The blue region shows the second harmonic generation of cortical bone by lasers. All images were stacked at 30 µm. Scale bar = 100 µm.