Microglia/macrophages proliferated after crush injury.

<p>Immunohistochemistry against BrdU, IBA1 and GFAP were performed in longitudinally sectioned optic nerves. A1–4. Contralateral control, no BrdU-IR was detected. B1–4. 1 week after crush, BrdU-IR colocalized with IBA1-IR. Arrowheads point at the crush site. C1–3. Magnified views of the three outlined regions in B4. C1 is the ONH, C2 is the crush site, and C3 is distal optic nerve. D1–3. Transvers sections of the ONH at the three locations indicated in C1. D1 is pre-lamina, D2 is the glial lamina, and D3 is post-lamina. Arrowheads in C1–3 and D1–3 point at colocalized BrdU-IR and IBA1-IR. The insert in D2 shows one microglia/macrophage with elongated BrdU-IR positive nuclei, indicating active cell division. Scale bars are 200 microns in A and B, 50 microns in C and D, and 20 microns in D2 insert.