Lucifer yellow uptake in developing rat retina: selective staining of horizontal cells

We have examined the uptake of Lucifer yellow CH by developing rat retina. We find that selective dye uptake occurs in retina incubated in vitro in the absence of external Ca2+. The pattern of uptake appears to depend on the developmental stage examined. Although little uptake is seen before postnatal day 5, between days 6 and 9, the dye selectively stains putative horizontal cell bodies and their process. Later, other cell bodies located deeper in the INL begin to show staining until day 21, when the uptake pattern becomes analogous to that seen in adult retina. By nearest neighbor analysis of labeled cell bodies in wholemounts of D-9 retina, we have shown that the labeled cells are distributed in a quasi-regular mosaic in the retina. Upon proteolytic dissociation of labeled retina, individual cells with Lucifer yellow fluorescence could be readily identified in the cell suspensions.