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RGS9 knockout causes a short delay in light responses of ON-bipolar cells.

Publication ,  Journal Article
Herrmann, R; Lee, B; Arshavsky, VY
Published in: PLoS One
2011

RGS9 and R9AP are components of the photoreceptor-specific GTPase activating complex responsible for rapid inactivation of the G protein, transducin, in the course of photoresponse recovery from excitation. The amount of this complex in photoreceptors is strictly dependent on the expression level of R9AP; consequently, the knockouts of either RGS9 or R9AP cause comparable delays in photoresponse recovery. While RGS9 is believed to be present only in rods and cones, R9AP is also expressed in dendritic tips of ON-bipolar cells, which receive synaptic inputs from photoreceptors. Recent studies demonstrated that knockouts of R9AP and its binding partner in ON-bipolar cells, RGS11, cause a small delay in ON-bipolar cell light responses manifested as a delayed onset of electroretinography b-waves. This led the authors to suggest that R9AP and RGS11 participate in regulating the kinetics of light responses in these cells. Here we report the surprising finding that a nearly identical b-wave delay is observed in RGS9 knockout mice. Given the exclusive localization of RGS9 in photoreceptors, this result argues for a presynaptic origin of the b-wave delay in this case and perhaps in the case of the R9AP knockout as well, since R9AP is expressed in both photoreceptors and ON-bipolar cells. We also conducted a detailed analysis of the b-wave rising phase kinetics in both knockout animal types and found that, despite a delayed b-wave onset, the slope of the light response is unaffected or increased, dependent on the light stimulus intensity. This result is inconsistent with a slowdown of response propagation in ON-bipolar cells caused by the R9AP knockout, further arguing against the postsynaptic nature of the delayed b-wave phenotype in RGS9 and R9AP knockout mice.

Duke Scholars

Published In

PLoS One

DOI

EISSN

1932-6203

Publication Date

2011

Volume

6

Issue

11

Start / End Page

e27573

Location

United States

Related Subject Headings

  • Retinal Bipolar Cells
  • RGS Proteins
  • Photoreceptor Cells
  • Mice, Knockout
  • Mice
  • Membrane Proteins
  • Light
  • General Science & Technology
  • Electroretinography
  • Animals
 

Citation

APA
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ICMJE
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Herrmann, R., Lee, B., & Arshavsky, V. Y. (2011). RGS9 knockout causes a short delay in light responses of ON-bipolar cells. PLoS One, 6(11), e27573. https://doi.org/10.1371/journal.pone.0027573
Herrmann, Rolf, Bowa Lee, and Vadim Y. Arshavsky. “RGS9 knockout causes a short delay in light responses of ON-bipolar cells.PLoS One 6, no. 11 (2011): e27573. https://doi.org/10.1371/journal.pone.0027573.
Herrmann R, Lee B, Arshavsky VY. RGS9 knockout causes a short delay in light responses of ON-bipolar cells. PLoS One. 2011;6(11):e27573.
Herrmann, Rolf, et al. “RGS9 knockout causes a short delay in light responses of ON-bipolar cells.PLoS One, vol. 6, no. 11, 2011, p. e27573. Pubmed, doi:10.1371/journal.pone.0027573.
Herrmann R, Lee B, Arshavsky VY. RGS9 knockout causes a short delay in light responses of ON-bipolar cells. PLoS One. 2011;6(11):e27573.

Published In

PLoS One

DOI

EISSN

1932-6203

Publication Date

2011

Volume

6

Issue

11

Start / End Page

e27573

Location

United States

Related Subject Headings

  • Retinal Bipolar Cells
  • RGS Proteins
  • Photoreceptor Cells
  • Mice, Knockout
  • Mice
  • Membrane Proteins
  • Light
  • General Science & Technology
  • Electroretinography
  • Animals