Figure 1.

Light micrographs of plastic-embedded P23H transgenic rat retinas taken at P130 (A and B) or P240 (C and D) from the posterior inferior region along the vertical meridian of the eye. (A) Uninjected eye from a rat at P130, which shows 3–4 rows of photoreceptor nuclei in the ONL, reduced from the normal 8–9 at this age. Photoreceptor inner segments (IS) and outer segments (OS) are shorter than normal, although still intact. RPE, retinal pigment epithelium. (B) Retina from the opposite eye from the same rat as in A, which was injected subretinally injected with Hh13 ribozyme at P15. About 6–7 rows of photoreceptor nuclei are present, and the photoreceptor inner and outer segments are about 70–80% of normal length. (C) Uninjected eye from a rat at P240, which shows only 1–2 rows of photoreceptor nuclei surviving, and only remnants of inner and outer segments present. (D) Retina from the opposite eye from the same rat in C, which was injected subretinally injected with Hh13 ribozyme at P15. About 4–5 rows of photoreceptor nuclei are still present and the inner and outer segments are almost as long as at P130 (B). Toluidine blue stain. (Bar = 20 μm.)