Figure 3.

(A) Injection of Po-pro-1 into a single A-type horizontal cell (center) extensively labeled the coupled mosaic of neighboring A-type horizontal cells. Focus is on the processes. (B) Injection of Po-pro-1 into a single B-type horizontal cell (arrow) labeled the soma and the initial processes of the injected cell. Nuclei of several coupled cells were also labeled. Two of these were subsequently injected with Lucifer Yellow to reveal the full B-type horizontal cell characteristic morphology shown to the left and right of the injected cell.