Adult Neural Retina Research Articles

Culture of adult rabbit retinal glial cells: methods and cellular origin of explant outgrowth.

Culture methods to propagate glial cells from the avascular adult rabbit neural retina are described. To determine the site(s) in the retina from which the cells originated, retina fragments were retrieved from culture at intervals after explanation and processed for light microscopy to localize surviving cells. Tritiated-thymidine radioautography was used to determine the time of onset and the localization of proliferating cells in the isolated retina and in the early culture outgrowth. Although some glial cells located just subjacent to the inner limiting membrane and at the interface between the ganglion cell and inner plexiform layers were activated to DNA synthesis in three to five days after explanation of the retina, the dominant cell type in the cultures derived from the retina appeared to be the Muller cell. Regionally, in isolated retina fragments, Muller cells became hyperplastic and formed tissue masses of proliferating cells surrounding photoreceptor remnants. These proliferating clusters could be retrieved from the culture medium after about 10 days in vitro and replated whereupon they attached to the culture substrate and gave rise to cellular outgrowths. The cells in the early explant outgrowth were heteromorphic, but passaged cultures contained a relatively homogeneous population of cells that exhibited a low maximal growth rate and senesced quickly in vitro.

Isolation and characterization of an unsaturated fatty acid-binding protein from developing chick neural retina.

An unsaturated fatty acid-binding protein has been isolated from the cytosol fraction of developing chick neural retina. It has a molecular weight of approximately 14,800 and specifically binds not only added radiolabeled arachidonic and oleic acids but has also been found to bind unsaturated fatty acids endogenously. This protein was detected in chick neural retina at all stages examined, from 8 to 16 days of development. It is also present in chick heart, brain, and retinal pigmented epithelium-choroid as well as in adult bovine neural retina. It is distinct from both cellular retinol-binding protein and cellular retinoic acid-binding protein on the bases of binding specificity and isoelectric point.

Collagen synthesis by rabbit neural retina in vitro and in vivo

Monolayer cultures established from explants of adult rabbit neural retina were used for studies of collagen biosynthesis. Preliminary characterization indicates that the cultures consist predominantly of astrocytic glial cells. Type I comprises 90% of the collagen secreted into the medium by these cultures. AB collagen is also produced. Approximately the same proportion of these macromolecules is secreted by explants as by cells through the fifth passage. Although evidence indicates that the neural retina of some avian species contributes to the vitreous matrix during embryogenesis, no type II-related vitreous collagen is found in the products of cultures of this tissue from the adult rabbit. Since glial cells from the retina have been identified in pathological vitreous membranes, it is of interest to determine if they synthesize collagen within the vitreous and if the type of collagen produced is influenced by the vitreous matrix. Neural retina cells propagated in cell culture were injected into the rabbit vitreous and the newly-synthesized collagen was marked with radiolabeled amino acids and analyzed by CNBr peptide analysis. As in cell culture, the major collagen produced by neural retina within the vitreous is type I. The secretion by these potentially invasive cells of a type of collagen not normally found within the vitreous may contribute to vitreous pathology.