The Transduction Cascade in Retinal ON-Bipolar Cells: Signal Processing and Disease

Annu Rev Vis Sci. 2017 Sep 15;3:25-51. doi: 10.1146/annurev-vision-102016-061338. Epub 2017 Jul 17.


Our robust visual experience is based on the reliable transfer of information from our photoreceptor cells, the rods and cones, to higher brain centers. At the very first synapse of the visual system, information is split into two separate pathways, ON and OFF, which encode increments and decrements in light intensity, respectively. The importance of this segregation is borne out in the fact that receptive fields in higher visual centers maintain a separation between ON and OFF regions. In the past decade, the molecular mechanisms underlying the generation of ON signals have been identified, which are unique in their use of a G-protein signaling cascade. In this review, we consider advances in our understanding of G-protein signaling in ON-bipolar cell (BC) dendrites and how insights about signaling have emerged from visual deficits, mostly night blindness. Studies of G-protein signaling in ON-BCs reveal an intricate mechanism that permits the regulation of visual sensitivity over a wide dynamic range.

Keywords: ON-bipolar neurons; regulators of G-protein signaling; scaffolding; signal transduction; synaptic transmission.

Publication types

  • Review

MeSH terms

  • Animals
  • GTP-Binding Protein Regulators / physiology
  • Humans
  • Night Blindness / physiopathology
  • Photoreceptor Cells, Vertebrate / physiology*
  • Retinal Bipolar Cells / physiology*
  • Signal Transduction / physiology*
  • Synaptic Transmission / physiology
  • Vision Disorders / physiopathology*
  • Visual Pathways / physiology*


  • GTP-Binding Protein Regulators