Tag Archives: retinal plasticity

Editorial: Special Issue on Retinal Remodeling

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Geoff Lewis and I worked over the last year or so to edit a special issue of Experimental Eye Research with a focus on Retinal Remodeling.  Our editorial for the issue is here. Pubmed link is here.

This special issue of Experimental Eye Research represents laboratories around the world that are involved in retinal degeneration research and was developed with two motivations: 1) to solicit manuscripts from our colleagues that would give broad, yet substantial insight into the various disorders associated with retinal degeneration and 2) to focus discussion in the vision research community into the negative plasticity now known as retinal remodeling that is associated with blinding diseases…

We selected an image for the cover from the Calkins lab (the center image in the above montage) that we felt was beautiful and represented the quality of work that went into every article in this issue and look forward to the dialogue that this special issue will foster.  Many thanks to: The Lewis/Fisher lab, the Calkins lab, the Vetter lab, the Lutty lab, the Gross lab, the Sagdullaev lab, the Merriman lab and Wei Li, Michael Kalloniatis and the Fletcher lab, the Cuenca lab, the Acosta lab, and everyone in our lab.

Webvision Chapter: Retinal Degeneration, Remodeling and Plasticity

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We have published a new chapter in Webvision, Retinal Degeneration, Remodeling and Plasticity that covers the history of the study of retinal degenerations and some of the implications for vision rescue.  Authors are Bryan W. Jones, Rebecca L. Pfeiffer and Robert E. Marc.  It will, like other Webvision chapters evolve over time, which is the whole point of Webvision, but we hope it will generate some discussion.

Constructive Retinal Plasticity After Selective Ablation of the Photoreceptors

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This abstract was presented today at the Association for Research in Vision and Opthalmology (ARVO) meetings in Seattle, Washington by Corinne N. Beier, Bryan W. Jones, Philip Huie, Yannis M. Paulus, Daniel Lavinsky, Loh-Shan B. Leung, Hiroyuki Nomoto,  Robert E. Marc, Daniel V. Palanker, and Alexander Sher.

Purpose: In the rabbit retina there is evidence of constructive retinal plasticity in response to focal ablation of a small patch of the photoreceptor layer by laser photocoagulation. After a two-month healing period, healthy photoreceptors migrate inwards filling the damaged area and restoring visual sensitivity to the lesion site. We investigated the integrity and function of the neural populations above the lesion, whether the migrating photoreceptors formed new connections with deafferented bipolar cells, and to what degree the new function resembled normal retinal function.

Methods: Retinal photocoagulation lesions of Moderate and Barely Visible clinical grades were produced in rabbits with a 532-nm laser, using beam diameter of 200 and 400 μm. Retinal ganglion cell (RGC) responses to spatio-temporal white noise stimulus were recorded on a 512-electrode array. Inner retinal neuron cell types were identified using Computational Molecular Phenotyping (CMP). Light evoked activity of the inner retinal neurons was measured through 1-amino-4-guanidobutane (AGB) labeling. Synaptic structure between photoreceptors and bipolar cells was characterized through transmission electron microscopy (TEM) imaging.

Results: The lesioned areas of the retina, after a two-month healing period, regained visual sensitivity. There was no significant difference between the response kinetics of RGCs with receptive fields covering the lesioned area and RGCs with receptive fields unaffected by the lesion. Furthermore, the average receptive field sizes of RGCs covering the lesion were consistent with the average receptive field sizes of RGCs unaffected by the lesion. CMP showed that all major inner retinal neuron cell types are present above both acute and healed lesions. Light evoked activity in the retina, as measured by AGB concentration levels, was diminished in the acute lesion but returned to within 10% of normal after two months. TEM images showed normal photoreceptor synaptic structure inside the healed lesion area.

Conclusions: Migrating photoreceptors establish new functional connectivity to deafferented bipolar cells and have normal synaptic structure. The new circuitry results in spatial and temporal properties of the RGC responses that resemble those of the healthy retina. In summary, the rewiring restores normal visual response in the lesioned area, indicating constructive retinal plasticity.

Support: Burroughs Wellcome Fund Career Award at the Scientific Interface; the Pew Charitable Trusts Scholarship in the Biomedical Sciences (A.S.), RPB CDA, Thome Foundation (BWJ), NIH EY02576, NIH EY015128, NSF 0941717, NIH EY014800 Vision Core (R.M.); NIH 5R01EY18608, AFOSR FA9550- 10-1-0503, DoD W81XWH-12-10575, Stanford University Bio-X (D.P.), Edward N. and Della L. Thome Memorial Foundation grant for Age-Related Macular Degeneration Research (BWJ) RPB unrestricted award (Moran Eye Center)