Journal
JOURNAL OF NEUROSCIENCE
Volume 26, Issue 45, Pages 11624-11636Publisher
SOC NEUROSCIENCE
DOI: 10.1523/JNEUROSCI.2296-06.2006
Keywords
retina; horizontal cells; gap junctions; connexin 50; confocal microscopy; dye coupling
Categories
Funding
- NEI NIH HHS [R01 EY006515, R01 EY012857-06A1, EY12857, EY06515, EY10608, R01 EY012857, P30 EY010608] Funding Source: Medline
Ask authors/readers for more resources
There are many examples of neuronal coupling via gap junctions in the retina. Of these, perhaps the best known is the extensive coupling between horizontal cells. In the rabbit retina, there are two types of horizontal cells, A-type and B-type, both of which are independently coupled. Connexin 50 (Cx50) cDNA, encoding a 440 aa protein, was successfully isolated from rabbit retina RNA. Cx50 was also obtained from isolated A-type horizontal cells (A-type HCs) by single-cell RT-PCR. A-type HCs were visualized by intracellular dye injection or with an antibody against calbindin. Confocal analysis revealed all Cx50 labeling occurred on the A-type HC matrix, typically at dendritic intersections. The Cx50 plaques varied in size, from punctate signals in which fine dendrites cofasciculated, to giant plaques, > 50 mu m(2),in which large dendrites crossed. The numerous Cx50 plaques between A-type HCs may adequately account for the remarkable coupling observed in this network. We could not detect Cx50 staining on the tips of horizontal cell dendrites within the cone pedicle invagination. This distribution does not support a role for Cx50 in hemichannel-mediated feedback. In addition, the absence of Cx50 in B-type HCs suggests the presence of a different connexin for this cell type. In summary, these results suggest that gap junctions in the A-type horizontal cell matrix are composed from Cx50. Multiple neuronal connexins are expressed in the mammalian retina and different cell types express specific connexins.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available