FIGURE 1. Glutamate induced retinal cell apoptosis and cell proliferation in adult mice.

(A) The number of TUNEL⁺ cells in vertical sections of the adult mouse retina prepared 1 day after subretinal injection of 1 µL of saline (Cont), L-glutamate (L-glu, 0.1–50 µg), or α-AA (1 µg). Apoptotic cells were significantly increased only after treatment with 50 µg of L-glutamate. ***P < 0.001 (two-tailed t-test). (B–D) BrdU⁺ cells in retinal sections 1 day after subretinal injection of (B) saline (Cont), (C) L-glutamate (L-glu; 1 µg), or (D) α-AA (1 µg), followed by retinal injection of BrdU (32.5 µM). Numerous BrdU⁺ cells were present in the ONL of retinas treated with L-glutamate or α-AA (1 µg) but not in saline-treated control retinas. Arrows: BrdU⁺ cells in the INL or OPL. GCL, ganglion cell layer. (E–I) BrdU labeling and pHisH3-immunoreactivity in retinal sections 1 day after subretinal injection of α-AA (1 µg) (E–H) or saline (I). Arrowheads: nuclei double-labeled with BrdU and pHisH3. (J–L) Photomicrographs of a retinal section taken at 24 hours after α-AA injection and labeled by TUNEL (green) and anti-BrdU (red). TUNEL (arrow) did not colocalize with anti-BrdU labeling. Scale bar: (B–G, I–L) 40 µm; (H) 16 µm.