Abstract
Purpose: :
3D-reaggregates from embryonic chicken retina are histotypically structured, presenting rosettes with photoreceptors and areas comparable to the inner retina, which surround cell-free neuropil spaces. Here we have analysed the cell-by-cell development of these areas resembling the formation of an inner plexiform layer (furtheron called IPLareas). In particular, roles of Müller cells and of FGF-2 were investigated.
Methods: :
Retinal spheroids were reaggregated in rotation culture from dissociated retinal cells of six days old chicken embryos. Cells were treated without/with 25 ng/ml FGF-2 for the whole culture period of up to 10 days. Sizes and shapes of spheres were analysed and quantified by light microscopy of sphere whole-mounts. Formation of IPLareas was investigated by immunohistochemistry of sphere cryosections, including antibodies to vimentin, transitin and glutamine synthetase (GS) to follow the development of immature and mature Müller cells, and several antibodies for amacrine cells, but also BrdU uptake and RT-PCR studies.
Results: :
IPLareas
Conclusions: :
Retinal spheroids are suitable to analyse basic constraints of IPL formation of the chicken retina. MCs have an active role in spatially organising the space of IPLareas. FGF-2 appears to stimulate these processes by acting directly upon MCs. It should be noted, that these processes occur in almost complete absence of ganglion cells, showing that IPL formation does not depend on GCs.
Keywords: retinal development • Muller cells • growth factors/growth factor receptors