title: Changes in ganglion cells during retinal degeneration.
abstract: Inherited retinal degeneration such as retinitis pigmentosa (RP) is associated with photoreceptor loss and concomitant morphological and functional changes in the inner retina. It is not known whether these changes are associated with changes in the density and distribution of synaptic inputs to retinal ganglion cells (RGCs). We quantified changes in ganglion cell density in rd1 and age-matched C57BL/6J-(wildtype, WT) mice using the immunocytochemical marker, RBPMS. Our data revealed that following complete loss of photoreceptors, (∼3months of age), there was a reduction in ganglion cell density in the peripheral retina. We next examined changes in synaptic inputs to A type ganglion cells by performing double labeling experiments in mice with the ganglion cell reporter lines, rd1-Thy1 and age-matched wildtype-Thy1. Ribbon synapses were identified by co-labelling with CtBP2 (RIBEYE) and conventional synapses with the clustering molecule, gephyrin. ON RGCs showed a significant reduction in RIBEYE-immunoreactive synapse density while OFF RGCs showed a significant reduction in the gephyrin-immmunoreactive synapse density. Distribution patterns of both synaptic markers across the dendritic trees of RGCs were unchanged. The change in synaptic inputs to RGCs was associated with a reduction in the number of immunolabeled rod bipolar and ON cone bipolar cells. These results suggest that functional changes reported in ganglion cells during retinal degeneration could be attributed to loss of synaptic inputs.
authors.affiliation: Department of Anatomy and Neuroscience, The University of Melbourne, Australia; NeuroEngineering Laboratory, Department of Electrical & Electronic Engineering, The University of Melbourne, Australia; Centre for Neural Engineering, The University of Melbourne, Australia.
authors.forename: Susmita
authors.initials: S
authors.lastname: Saha
authors.affiliation: Department of Anatomy and Neuroscience, The University of Melbourne, Australia.
authors.forename: Ursula
authors.initials: U
authors.lastname: Greferath
authors.affiliation: Department of Anatomy and Neuroscience, The University of Melbourne, Australia.
authors.forename: Kirstan A
authors.initials: KA
authors.lastname: Vessey
authors.affiliation: NeuroEngineering Laboratory, Department of Electrical & Electronic Engineering, The University of Melbourne, Australia; Centre for Neural Engineering, The University of Melbourne, Australia; NICTA Victoria Research Laboratory, c/- Dept. of Electrical & Electronic Engineering, The University of Melbourne, Australia; Bionics Institute, East Melbourne, Australia.
authors.forename: David B
authors.initials: DB
authors.lastname: Grayden
authors.affiliation: NeuroEngineering Laboratory, Department of Electrical & Electronic Engineering, The University of Melbourne, Australia; Centre for Neural Engineering, The University of Melbourne, Australia; NICTA Victoria Research Laboratory, c/- Dept. of Electrical & Electronic Engineering, The University of Melbourne, Australia; Bionics Institute, East Melbourne, Australia.
authors.forename: Anthony N
authors.initials: AN
authors.lastname: Burkitt
authors.affiliation: Department of Anatomy and Neuroscience, The University of Melbourne, Australia. Electronic address: elf@unimelb.edu.au.
authors.forename: Erica L
authors.initials: EL
authors.lastname: Fletcher
mesh_terms: D000429:Alcohol Oxidoreductases; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002452:Cell Count; D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins / Q000378:metabolism; D004195:Disease Models, Animal; D007150:Immunohistochemistry; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018613:Microscopy, Confocal; D009433:Neural Inhibition; D009434:Neural Pathways / Q000378:metabolism / Q000473:pathology; D009473:Neuronal Plasticity; D010750:Phosphoproteins / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D051245:Retinal Bipolar Cells / Q000378:metabolism / Q000473:pathology; D012162:Retinal Degeneration / Q000378:metabolism / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000378:metabolism / Q000473:pathology*; D013569:Synapses / Q000378:metabolism / Q000473:pathology*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D056970:Co-Repressor Proteins; D004268:DNA-Binding Proteins; D008164:Luminescent Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; C119265:Rbpms protein, mouse; C073441:gephyrin; C054562:yellow fluorescent protein, Bacteria; D000429:Alcohol Oxidoreductases; C111341:Ctbp2 protein, mouse
keywords: ganglion cell; inner plexiform layer; plasticity; retina; retinitis pigmentosa