Figure 2.

Morphology, dendritic stratification and melanopsin immunoreactivity of the two ganglion-cell types encountered among GFP-positive RGCs in Cdh3-GFP mice. Cells were targeted for dye filling based on GFP fluorescence. (a-c) Morphology of the preponderant cell type, a bistratified cell with a relatively small arbor of spiny dendrites. a: a pseudocolored view of the bistratified type as viewed en face ; green and cyan dendrites are in the ON sublayer, magenta in the OFF sublayer. Cyan dendrites are recurrent, returning to the ON sublayer having traveled at least a small distance in the OFF sublayer. Scale bar (50 μm) applies to (a) and (e). (b-c) Side view projections of this filled cell in relation to the two strata of melanopsin-immunopositive dendrites (blue) or the cholinergic bands, revealed by anti-VAChT immunolabeling (magenta). (d) Example of the somatic anti-melanopsin immunoreactivity observed in a fraction of the somas of cells of this type. Scale bar: 10 μm. (e-f) Morphology of the monostratified GFP-positive RGC type in the Cdh3-GFP mouse, apparently equivalent to the M5 ipRGC type (Stabio et al., 2018). (e) An en face view color coded as in (a); all dendrites stratify in the ON sublayer (green). (f) Side view projection, showing stratification almost entirely below the ON cholinergic band.