Figure 6. Comparison of immunofluorescence for the calcium binding proteins, calretinin and calbindin-28 kDa, and voltage-gated sodium channel antibodies in the ganglion cell layer (GCL)/nerve fiber layer (NFL) as seen in retinal whole-mounts. A-C: Calcium binding proteins (CBP) in the NFL are extensively colocalized with Pan-NaV. Some Pan-Na_V stained retinal ganglion cell (RGC) somata were also immunopositive for CBPs (arrowhead) while others were not (double arrows). Initial segments of RGCs, (arrow) some of which can be seen emerging from the RGC somata, were immunopositive for Pan-Na_V but not colabeled with CBPs. D-F: Na_V1.1-immunopositive (green) RGC nerve fiber bundles in the nerve fiber layer (NFL) were colabeled with CBPs (red), but the axon initial segments (arrow) were not. G-I: Na_V1.2 immunopositive (green) RGC nerve fiber bundles in the NFL were colabeled with CBPs (red) but not the axon initial segments (arrow). J-K: Na_V1.6 immunopositive (green) axon initial segments (arrow) were not colabeled with CBPs (red). Scale bar equals 20 µm. Abbreviations: bv is blood vessel.