Connexin36 is essential for transmission of rod-mediated visual signals in the mammalian retina.
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.
Deans
Michael R
MR
Department of Neurobiology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
Volgyi
Bela
B
Goodenough
Daniel A
DA
Bloomfield
Stewart A
SA
Paul
David L
DL
D000469:Alkaline Phosphatase; D025042:Amacrine Cells / Q000166:cytology / Q000378:metabolism; D000818:Animals; D017630:Connexins / Q000172:deficiency* / Q000235:genetics; D015350:Contrast Sensitivity / Q000235:genetics; D058851:GPI-Linked Proteins; D017629:Gap Junctions / Q000378:metabolism*; D017930:Genes, Reporter / Q000235:genetics; D005998:Glycine / Q000378:metabolism; D007150:Immunohistochemistry; D007395:Interneurons / Q000166:cytology / Q000378:metabolism*; D007527:Isoenzymes / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D010775:Photic Stimulation; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000378:metabolism*; D017948:Retinal Rod Photoreceptor Cells / Q000166:cytology / Q000378:metabolism*; D012684:Sensory Thresholds / Q000502:physiology; D009435:Synaptic Transmission / Q000235:genetics*; D014785:Vision, Ocular / Q000235:genetics; D001616:beta-Galactosidase / Q000235:genetics; D000097004:Gap Junction delta-2 Protein
D000469:Alkaline Phosphatase; D017630:Connexins; D058851:GPI-Linked Proteins; D005998:Glycine; D007527:Isoenzymes; D001616:beta-Galactosidase; D000097004:Gap Junction delta-2 Protein; C019839:alkaline phosphatase, placental