Connexin45 mediates gap junctional coupling of bistratified ganglion cells in the mouse retina.
Direction selectivity, a key feature of visual perception, originates in the retina and is transmitted by bistratified ganglion cells that, in the rabbit retina, exhibit a particular coupling pattern. We intracellularly labeled ganglion cells in different transgenic mouse lines, allowing a morphological classification of bistratified ganglion cells, an analysis of their coupling pattern, and the molecular identification of the connexins responsible for the coupling. Based on dendritic characteristics including co-fasciculation with the dendrites of cholinergic starburst amacrine cells, we were able to distinguish three types of bistratified ganglion cells. Two of these co-fasciculate with starburst amacrine cells and exhibit a specific homologous coupling pattern. Connexin45 (Cx45) appears to be the major component of the gap junctional channels because tracer coupling is absent in Cx45-deficient animals whereas it persists in Cx36-deficient animals. It is speculated that the transjunctional voltage dependence of Cx45 channels could support the transmission of direction selectivity.
Schubert
Timm
T
Institute of Biology, University of Oldenburg, D-26111 Oldenburg, Germany.
Maxeiner
Stephan
S
Krüger
Olaf
O
Willecke
Klaus
K
Weiler
Reto
R
D000818:Animals; D001710:Biotin / Q000378:metabolism; D048429:Cell Size; D017630:Connexins / Q000172:deficiency / Q000378:metabolism / Q000502:physiology*; D003712:Dendrites / Q000378:metabolism; D005136:Eye Proteins / Q000378:metabolism; D017629:Gap Junctions / Q000145:classification / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000235:genetics; D007381:Intermediate Filament Proteins / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D012160:Retina / Q000166:cytology*; D012165:Retinal Ganglion Cells / Q000145:classification / Q000166:cytology* / Q000378:metabolism*; D000097004:Gap Junction delta-2 Protein
D001710:Biotin; D017630:Connexins; D005136:Eye Proteins; D049452:Green Fluorescent Proteins; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; D064231:Nestin; D000097004:Gap Junction delta-2 Protein; C577485:Nes protein, mouse; C082920:connexin 45