[Reconstruction of the neuroretina from embryonic chick retinal cells in floating culture and the effect of growth factors].

We observed the three dimensional structure of cellular aggregates formed from chick retinal cells in a floating culture system for 2 months. The aggregated cells partially mimicked the structure of the retina and showed differentiation of photoreceptor cells and Müller cells with numerous synapses. Immunohistochemical studies showed the number of anti-rhodopsin positive cells increasing over time. In the long-term culture, increasing anti-crystalline positive cells appeared late in the culture, indicative of differentiation of lens epithelial cells. Nerve, epidermal, and basic fibroblast growth factors, and co-culture with retinal pigment epithelial cells stimulated to some degree the growth of dendrites in retinal cellular aggregates. Epidermal growth factor, in particular, promoted the production of rhodopsin in photoreceptor cells. Retinal cellular aggregates in a floating culture system could be used to examine the effect of various factors on differentiation of the neuroretina.