Development and degeneration of cone bipolar cells are independent of cone photoreceptors in a mouse model of retinitis pigmentosa

PLoS One. 2012;7(8):e44036. doi: 10.1371/journal.pone.0044036. Epub 2012 Aug 31.

Abstract

Retinal photoreceptors die during retinal synaptogenesis in a portion of retinal degeneration. Whether cone bipolar cells establish regular retinal mosaics and mature morphologies, and resist degeneration are not completely understood. To explore these issues, we backcrossed a transgenic mouse expressing enhanced green fluorescent protein (EGFP) in one subset of cone bipolar cells (type 7) into rd1 mice, a classic mouse model of retinal degeneration, to examine the development and survival of cone bipolar cells in a background of retinal degeneration. Our data revealed that both the development and degeneration of cone bipolar cells are independent of the normal activity of cone photoreceptors. We found that type 7 cone bipolar cells achieved a uniform tiling of the retinal surface and developed normal dendritic and axonal arbors without the influence of cone photoreceptor innervation. On the other hand, degeneration of type 7 cone bipolar cells, contrary to our belief of central-to-peripheral progression, was spatially uniform across the retina independent of the spatiotemporal pattern of cone degeneration. The results have important implications for the design of more effective therapies to restore vision in retinal degeneration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / pathology
  • Animals
  • Axons / metabolism
  • Cell Shape
  • Dendrites / metabolism
  • Disease Models, Animal
  • Green Fluorescent Proteins / metabolism
  • Mice
  • Mice, Transgenic
  • Mosaicism
  • Retinal Bipolar Cells / metabolism
  • Retinal Bipolar Cells / pathology*
  • Retinal Cone Photoreceptor Cells / metabolism
  • Retinal Cone Photoreceptor Cells / pathology*
  • Retinitis Pigmentosa / metabolism
  • Retinitis Pigmentosa / pathology*
  • Time Factors

Substances

  • Green Fluorescent Proteins

Grants and funding

This work was supported by University of Hong Kong Seed Funding Program for Basic Research and General Research Fund from the Hong Kong Research Grants Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.