Fig. 4.

Confocal micrographs of vertical frozen sections through mouse retina that were doubly labeled for the calcium-binding protein CaB5 and protein kinase Cα (PKCα; A–D) or for CaB5 and glycine (E–G). A: CaB5 immunoreactivity is found in many bipolar cell perikarya, in their descending axons, and in three distinct bands of axon terminals. B: PKCα labels rod bipolar (RB) cells, their descending axons, and their axon terminals in the innermost IPL. Comparison with A shows that RB axon terminals also express CaB5. C: High-power micrograph showing the CaB5-immunolabeled cell bodies from the boxed area in A. D: PKCα-immunolabeled cell bodies from the corresponding area in B. The asterisks indicate the double-labeled RB cell perikarya. E: CaB5-labeled section. F: Same section as in E labeled for glycine (GLY). The three arrows indicate bipolar cells expressing both CaB5 and glycine. The arrowheads indicate bipolar cells that express CaB5 but not glycine. G: Superimposition of E and F. Scale bar = 25 μm for A,B,E,F,G, 11.4 μm for C,D.