Fig. 2. Chicken horizontal cells are classified into three subtypes based on their morphology. (A-C) Confocal images of three types of horizontal cells. Projection images and optical vertical sections are shown in upper and lower panels, respectively. (A) Type I horizontal cell with a small, bushy dendritic field and a single long axon (arrow). (B) Type II horizontal cell with large and highly branched dendritic arbors. (C) Type III horizontal cell with simple, less branched dendrites that contains bulge-like terminals (arrows). (D) The three subtypes of horizontal cell are shown in the same scale. (E) Expression of N-cadherin mRNA in the E16 retina. Chicken N-cadherin (cNcad, arrowheads) is expressed in all the horizontal cells that strongly express Prox1 (green, arrows). Scale bars: 10 µm in A-D; 20 µm in E.