Connexin36 is essential for transmission of rod-mediated visual signals in the mammalian retina

Neuron. 2002 Nov 14;36(4):703-12. doi: 10.1016/s0896-6273(02)01046-2.

Abstract

To examine the functions of electrical synapses in the transmission of signals from rod photoreceptors to ganglion cells, we generated connexin36 knockout mice. Reporter expression indicated that connexin36 was present in multiple retinal neurons including rod photoreceptors, cone bipolar cells, and AII amacrine cells. Disruption of electrical synapses between adjacent AIIs and between AIIs and ON cone bipolars was demonstrated by intracellular injection of Neurobiotin. In addition, extracellular recording in the knockout revealed the complete elimination of rod-mediated, on-center responses at the ganglion cell level. These data represent direct proof that electrical synapses are critical for the propagation of rod signals across the mammalian retina, and they demonstrate the existence of multiple rod pathways, each of which is dependent on electrical synapses.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alkaline Phosphatase
  • Amacrine Cells / cytology
  • Amacrine Cells / metabolism
  • Animals
  • Connexins / deficiency*
  • Connexins / genetics
  • Contrast Sensitivity / genetics
  • GPI-Linked Proteins
  • Gap Junction delta-2 Protein
  • Gap Junctions / metabolism*
  • Genes, Reporter / genetics
  • Glycine / metabolism
  • Immunohistochemistry
  • Interneurons / cytology
  • Interneurons / metabolism*
  • Isoenzymes / genetics
  • Mice
  • Mice, Knockout
  • Photic Stimulation
  • Presynaptic Terminals / metabolism*
  • Presynaptic Terminals / ultrastructure
  • Retinal Cone Photoreceptor Cells / cytology
  • Retinal Cone Photoreceptor Cells / metabolism
  • Retinal Ganglion Cells / cytology
  • Retinal Ganglion Cells / metabolism*
  • Retinal Rod Photoreceptor Cells / cytology
  • Retinal Rod Photoreceptor Cells / metabolism*
  • Sensory Thresholds / physiology
  • Synaptic Transmission / genetics*
  • Vision, Ocular / genetics
  • beta-Galactosidase / genetics

Substances

  • Connexins
  • GPI-Linked Proteins
  • Isoenzymes
  • Alkaline Phosphatase
  • alkaline phosphatase, placental
  • beta-Galactosidase
  • Glycine