Photoreceptor calcium channels: Insight from night blindness

Catherine W. Morgans, Philippa R. Bayley, Nicholas W. Oesch, Gaoying Ren, Lakshmi Akileswaran, W. Rowland Taylor

Research output: Contribution to journalArticle

89 Scopus citations

Abstract

The genetic locus for incomplete congenital stationary night blindness (CSNB2) has been identified as the CACNA1f gene, encoding the α1F calcium channel subunit, a member of the L-type family of calcium channels. The electroretinogram associated with CSNB2 implicates α1F in synaptic transmission between retinal photoreceptors and bipolar cells. Using a recently developed monoclonal antibody to α1F, we localize the channel to ribbon active zones in rod photoreceptor terminals of the mouse retina, supporting a role for α1F in mediating glutamate release from rods. Detergent extraction experiments indicate that α1F is part of a detergent-resistant active zone complex, which also includes the synaptic ribbons. Comparison of native mouse rod calcium currents with recombinant α1F currents reveals that the current-voltage relationship for the native current is shifted approximately 30 mV to more hyperpolarized potentials than for the recombinant α1F current, suggesting modulation of the native channel by intracellular factors. Lastly, we present evidence for L-type α1D calcium channel subunits in cone terminals of the mouse retina. The presence of α1D channels in cones may explain the residual visual abilities of individuals with CSNB2.

Original languageEnglish (US)
Pages (from-to)561-568
Number of pages8
JournalVisual neuroscience
Volume22
Issue number5
DOIs
StatePublished - Sep 1 2005

Keywords

  • CSNB2
  • Calcium channel
  • Photoreceptor
  • Ribbon synapse
  • Synaptic transmission

ASJC Scopus subject areas

  • Physiology
  • Sensory Systems

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    Morgans, C. W., Bayley, P. R., Oesch, N. W., Ren, G., Akileswaran, L., & Taylor, W. R. (2005). Photoreceptor calcium channels: Insight from night blindness. Visual neuroscience, 22(5), 561-568. https://doi.org/10.1017/S0952523805225038