Molecular Profiling of Small and Large Retinal Ganglion Cells

Different sub-types of ganglion cells existing in mammalian retinas possessing distinct function in processing the visual information. In primates, RGC are commonly divided into midget cells, which are relatively small, and parasol cells, with a larger soma size. Rodents also possess morphologically distinct populations, but their physiological properties are less characterized. The two types of mammalian RGCs differ in their response to pathological conditions such as retinal ischemia, diabetic retinopathy and glaucoma. In this work, we compared gene expression profiles of large (LRGCs) and small (SRGCs) ganglion cells isolated from rat retina in attempt to identify molecular determinants underlying differences in function and tolerance to stress. Keywords: comparative hybridization Rat RGCs retrogradely labeled with 4DI-10ASP were purified from freshly dissected retinas and subjected to fluorescent-activated cell sorting (FACS) in order to separate the SRGC and LRGC sub-populations. Actinomycin D was added to prevent new transcription during experimental procedures. Purified cells were used for RNA isolation. Following two rounds of linear amplification aRNA probes were hybridized with two-color Agilent Rat Genomic Oligo Arrays. We utilized the dye swap experimental design to eliminate the dye bias effects and make data from different experiments available for the cross-comparison.