Fig 7. Placement of lens and measurement of glial scar.

A. Coronal slice containing the track of an implanted GRIN lens is outlined with a dotted yellow line. The implant depth was 935 μm below the pial surface. B. Coronal slice stained with anti-GFAP antibody. The white dashed lines denote the mean thickness of the glial scar under the lens, which was 45.9 ± 4.2 μm (mean ± SEM, 40 areas, 3 mice). The working distance of the GRIN lens, which was 125 μm, is much longer than the thickness of the scar. Therefore, the cells within 125 μm of the lens are too close for inclusion in any in vivo images. A solid light yellow line denotes the region that can be visualized with the GRIN lens and multiphoton microscopy (imaging region). The GFAP+ cells in the imaging region were relatively few and exhibited only weak immunoreactivity compared with the scar. The inset is an enlargement of this area (inset was brightened and contrast was increased to show relatively faint staining). C. An area in the ventrolateral cortex of the contralateral hemisphere was used as a negative control. A solid light yellow line denotes the region which is at the same depth and size as the imaging region and in the same orientation with respect to the pial surface. The inset is an enlargement of this area (inset was brightened and contrast was increased to show relatively faint staining). The number of GFAP+ cells were not significantly different for the imaged region and the negative control region (p = 0.36). Scale bars are 200 μm for A and 100 μm for B and C.