Chicken Embryo Retinal Ganglion Cells, A Tool For Neuronal Research

PANZETTA P; BROCCO M; CONTIN MA; CARPENTIERI AR; GUIDO ME

Current Trends in Neurology, vol 2

Research Trends, ISSN 0972-8252

Lugar: Poojapura, Trivandrum ? 695012 India; Año: 2006; p. 47 - 57

Retinal ganglion cells (RGCs) are the only projecting neurons in retina. Taking advantage of having these cells purified, we have performed developmental, biochemical and circadian studies. Anti-chicken Thy-1 sera were raised to accomplish panning purification of RGCs. From 7-days-old embryo (E7) retina, we obtained two different populations of RGCs. By gentle washing and successive panning, we obtained a population of antibody loosely bound cells (LBCs), mostly immature. And after exhaustive washing we harvested a small population of tightly bound cells (TBCs), characterized as mature RGCs. Latter cells cultured at low density in a tailored growth factor lacking medium, survived and regrew their processes. Evaluation of process regrowth was determined by neurofilament cell-ELISA. Substrata of several extracellular matrix proteins modulated the cell development. In cultures performed on thrombospondin, a disintegrin (flavoridin) produced a dose-response inhibition, suggesting an integrin-thrombospondin receptor(s) interaction(s) on process regrowth. Neurotrophic factors (NTFs) and depolarization improved regrowth on LBC cultures, while they did not affect survival and regrowth on TBC cultures. Moreover, addition of multiple NTFs caused cell death in latter cultures. Consequently, chicken RGC system would approach insight on phenomena elicited by NTFs in CNS neurons, which evoke survival and death pathways. Cultures of RGCs from E8 retina, in which the photoreceptors have not still developed displayed a circadian fluctuation in phospholipid labeling and synthesized melatonin?like indole. They showed circadian rhythms in the expression of mRNA of arylalkylamine N-acetyltransferase, a key enzyme in melatonin synthesis. Therefore, RGCs would constitute primary retinal circadian oscillators.