Fig. 1.

Loss of ganglion cells in LXRβ^−/− mice. The ganglion cells appear normal in both 6-mo-old WT and LXRβ^−/− mice, and the nerve layer (arrow) is visible in both (A–D). In 16-mo-old WT mouse eyes, the ganglion cells are still normal, and the nerve fiber layer is visible (E and F). In 16-mo-old LXRβ^−/− mouse eyes, the number of ganglion cells is markedly reduced (***P < 0.001) as is the nerve fiber layer (G–I). n = 4. (Scale bars: A, C, E, and G, 200 μm; B, D, F, and H, 50 μm.)