Figure 1. Toluidine blue staining of semithin sections from control explants. Neuroretinal morphology was preserved after experimental retinal detachment (A). At day 3 of culture (B), photoreceptor outer segments (OS) were truncated and disrupted and the neuroretina began to degenerate and become thinner. Vacuolization of the ganglion cell layer (GCL) and inner nuclear layer (INL) was apparent. The outer nuclear layer (ONL) showed 6–7 rows of photoreceptor nuclei as in post-detached specimens, but at this time point they were loosely distributed. Fragmented OS were present in the subretinal space (ellipsoid area). After 6 days of culture (C), the number of rows of nuclei was reduced in the INL, but remained constant in the ONL. The neuroretinal thickness continued to decrease, mainly due to narrowing of the plexiform layers. Fragmented OS remained present in the subretinal space (ellipsoid area). After 9 days in culture, explants that maintained the retinal architecture (D) revealed a lower packing density of cells, and there was a marked reduction in the number of nuclei in the INL. The plexiform layers almost disappeared and a tissue layer was present outside the outer limiting membrane (OLM; arrows). In explants that showed cellular disorganization (E), nuclei were randomly arranged, appearing outside the OLM and comprised a new multinuclear tissue layer in the subretinal space (arrows). Comparing (A-E) images, the retinal thinning during the culture is apparent. On days 3, 6, and 9, the ONL looked progressively thicker (B-D). Scale bar equals 20 µm. Abbreviations: inner nuclear layer (INL); nerve fiber layer (NFL).