Electroretinographic assessment of rod- and cone-mediated bipolar cell pathways using flicker stimuli in mice

Sci Rep. 2015 Jun 1;5:10731. doi: 10.1038/srep10731.

Abstract

Mouse full-field electroretinograms (ERGs) are dominated by responses of photoreceptors and depolarizing (ON-) bipolar cells, but not much of hyperpolarizing (OFF-) bipolar cells under conventional recording conditions. Here we investigate a novel ERG protocol in mice for functional assessment of the major ON- and OFF-bipolar cell pathways using flicker stimuli for a high luminance with varying frequency up to 30 Hz. Wild-type (WT) and functionally specific transgenic mice (Cnga3(-/-), no cone photoreceptor function; rho(-/-), no rod photoreceptor function; mGluR6(-/-), no ON-bipolar cell function) were examined. The Cnga3(-/-) flicker ERG was similar to the WT flicker ERG at very low stimulus frequencies, whereas ERGs were comparable between WT and rho(-/-) mice at 5 Hz and above. Between 5 and 15 Hz, ERGs in mGluR6(-/-) mice differed in configuration and amplitude from those in WT and rho(-/-) mice; in contrast, response amplitudes above 15 Hz were comparable among WT, rho(-/-) and mGluR6(-/-) mice. In summary, we found three frequency ranges with these conditions that are dominated by activity in the rod pathways (below 5 Hz), cone ON-pathway (between 5 and 15 Hz), and cone OFF-pathway (above 15 Hz) that enables a quick overview of the functionality of the major bipolar cell pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Electroretinography*
  • Evoked Potentials, Visual
  • Mice
  • Mice, Knockout
  • Photic Stimulation*
  • Retinal Cone Photoreceptor Cells / metabolism*
  • Retinal Rod Photoreceptor Cells / metabolism*
  • Signal Transduction*