title: Retinal remodeling triggered by photoreceptor degenerations.
abstract: Many photoreceptor degenerations initially affect rods, secondarily leading to cone death. It has long been assumed that the surviving neural retina is largely resistant to this sensory deafferentation. New evidence from fast retinal degenerations reveals that subtle plasticities in neuronal form and connectivity emerge early in disease. By screening mature natural, transgenic, and knockout retinal degeneration models with computational molecular phenotyping, we have found an extended late phase of negative remodeling that radically changes retinal structure. Three major transformations emerge: 1) Müller cell hypertrophy and elaboration of a distal glial seal between retina and the choroid/retinal pigmented epithelium; 2) apparent neuronal migration along glial surfaces to ectopic sites; and 3) rewiring through evolution of complex neurite fascicles, new synaptic foci in the remnant inner nuclear layer, and new connections throughout the retina. Although some neurons die, survivors express molecular signatures characteristic of normal bipolar, amacrine, and ganglion cells. Remodeling in human and rodent retinas is independent of the initial molecular targets of retinal degenerations, including defects in the retinal pigmented epithelium, rhodopsin, or downstream phototransduction elements. Although remodeling may constrain therapeutic intervals for molecular, cellular, or bionic rescue, it suggests that the neural retina may be more plastic than previously believed.
authors.affiliation: John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah 84132. bryan.jones@m.cc.utah.edu
authors.forename: Bryan W
authors.initials: BW
authors.lastname: Jones
authors.forename: Carl B
authors.initials: CB
authors.lastname: Watt
authors.forename: Jeanne M
authors.initials: JM
authors.lastname: Frederick
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Baehr
authors.forename: Ching-Kang
authors.initials: CK
authors.lastname: Chen
authors.forename: Edward M
authors.initials: EM
authors.lastname: Levine
authors.forename: Ann H
authors.initials: AH
authors.lastname: Milam
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Lavail
authors.forename: Robert E
authors.initials: RE
authors.lastname: Marc
mesh_terms: D000375:Aging; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D016923:Cell Death; D002465:Cell Movement / Q000502:physiology*; D004195:Disease Models, Animal; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007150:Immunohistochemistry; D007211:Indoles / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008854:Microscopy, Electron; D009154:Mutation; D009457:Neuroglia / Q000378:metabolism / Q000648:ultrastructure; D009474:Neurons / Q000145:classification / Q000378:metabolism / Q000648:ultrastructure; D010641:Phenotype; D010786:Photoreceptor Cells / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D010857:Pigment Epithelium of Eye / Q000378:metabolism; D051381:Rats; D012162:Retinal Degeneration / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D012243:Rhodopsin / Q000235:genetics; D013569:Synapses / Q000145:classification / Q000378:metabolism / Q000648:ultrastructure; D013654:Taurine / Q000378:metabolism; D014048:Tolonium Chloride / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D000596:Amino Acids; D007211:Indoles; D014048:Tolonium Chloride; D013654:Taurine; C007293:DAPI; D005680:gamma-Aminobutyric Acid; D012243:Rhodopsin; D005978:Glutathione