The Journal of Neuroscience, November 8, 2006, ():
Coupling between A-Type Horizontal Cells Is Mediated by Connexin 50 Gap Junctions in the Rabbit Retina
J. Neurosci. O'Brien et al.
26: 11624
Supplemental Data
Files in this Data Supplement:
- supplemental material
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Supplementary Figure 1: A schematic diagram of a cone pedicle, showing the comparative levels of post-synaptic processes.
This illustration is provided to explain the labeling strategy to demonstrate that Cx50 plaques occur below the base of the cone pedicle. A cone pedicle is shown with several invaginations at the synaptic ribbons. Horizontal cell dendrites approach close to the synaptic ribbon, high and lateral (red). The proposed location of hemichannels is on the tips of the horizontal cell dendrites, confined within the synaptic invagination, close to the site of glutamate release (yellow dots). The dendrites of ON cone bipolar cells (green), bearing mGluR6 receptors, also invaginate and take a high central position. In contrast, OFF cone bipolar cells (blue) make basal synapses, some with GluR5 receptors, at a distinctly lower level. Finally beneath the cone pedicle, there is a plexus of converging dendrites including those from several different horizontal cells. Gap junctions occur between horizontal cell dendrites at this level below the cone pedicle (paired yellow lines). Thus, to see if hemichannel labeling can be detected, it is necessary to determine if the Cx50 labeling is above or below the base of the cone pedicle, marked by GluR5 antibody. Modified from Haverkamp et al. (2000) with permission from Heinz Wässle.
- supplemental material
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Supplementary Figure 2: Cx50 forms gap junctions between A-type horizontal cells in the cat retina.
Whole mounts of cat retina were double labeled with antibodies against calbindin (red) and Cx50 (green). The thick primary dendrites of the cat A-type HCs are clearly visible, forming a matrix similar to the rabbit retina. Cx50 plaques occurred on the calbindin labeled A-type HC network at dendritic intersections. Additionally, the Cx50 plaques in the cat retina had similar size variability, from small puncta on fine dendritic crossover to large plaques at the intersections of primary dendrites. Thus, Cx50 may account for the coupling of axonless horizontal cells in other mammalian species. Scale, 5µm.
