Tyramine immunofluorescence in the lamina and medulla.

<p><b>A–C</b>: Single horizontal optical sections through the lamina (La, thickness = 1 µm), stained with anti-tyramine (magenta in A,C), the nuclear marker DAPI (blue in B,C), and anti-synapsin (green in A–C). About one fourth of LMCs were double-labeled with anti-tyramine and DAPI (arrowheads), whereas others were exclusively labeled with DAPI (arrows). <b>D–F</b>: Horizontal section of the medulla (Me), double-labeled with anti-tyramine (magenta in D,F) and anti-synapsin (green in E,F). The proximal part of layer 2 exhibits moderate tyramine immunoreactivity (arrow in D), which is attributable to terminals of tyramine-positive LMCs. Layers 4 and 5 are supplied with widely branching tyramine-positive fibers. Thin fibers in layers 6–8 (arrowheads in D) are axons derived from the cell bodies in the first optic chiasma (see also Fig. 6E,F). Numbers in E indicate medulla layers. Scale bar = 50 µm in C (applies to A,B),F (applies to D,E).