Figure 5

Amacrine tyrosine hydroxylase (TH)-positive cells express c-fos in response to light and localize mainly in the peripheral retina. (A) In situ hybridization against c-fos of a central retinal section from a Stage 42 tadpole exposed to light (2500 lux, 30 minutes) followed by immunohistochemistry against TH. Insets show higher magnification of a c-fos+ / TH + cell. (B) Percentage of TH + cells relative to the total number of c-fos + cells in each central retinal section is indicated by a dot; the horizontal line represents the mean (n = 10). (C) Percentage of TH + cells exhibiting c-fos induction by light. The number of cells counted is indicated. (D) Transverse section of the eye from a Stage 42 tadpole showing a representative in situ hybridization label for opn4m and immunohistochemistry results for TH. Merge image is shown in the right panel. mHC (arrowheads) and mRGC (arrows) are indicated. (E) Distribution of TH + cells counted in consecutive sections throughout the whole eye, divided into two peripheral areas and one central area. The percentage of the cells located in each region and the total numbers of cells counted (mean ± SD; n = 3 eyes) are indicated. (F) Morphology of the TH + cells. Stage 28 embryos were electroporated with a GFP construct. At Stage 42, Double-positive cells (TH + and GFP+) were revealed by immunohistochemistry. Examples of two cells are shown, with the merged image shown on the left, and the higher magnification of the TH + (red) and GFP (green) cells shown in the right panels. Neurite extensions (TH+ / GFP+; arrow) oriented to the inner plexiform layer (IPL), and neurites (TH− / GFP+; arrowhead) oriented to the outer plexiform layer (OPL), are indicated. The IPL and OPL are shown by dots. INL, inner nuclear layer; ONL, outer nuclear layer; RGC, retinal ganglion cell layer.