PUBLICATION
Specific connectivity between photoreceptors and horizontal cells in the zebrafish retina
- Authors
- Klaassen, L.J., de Graaff, W., Van Asselt, J.B., Klooster, J., Kamermans, M.
- ID
- ZDB-PUB-161007-7
- Date
- 2016
- Source
- Journal of neurophysiology 116(6): 2799-2814 (Journal)
- Registered Authors
- Kamermans, Maarten
- Keywords
- connexins, horizontal cells, photoreceptors, retina, zebrafish
- MeSH Terms
-
- Microscopy, Electron
- Oocytes
- Biotin/analogs & derivatives
- Biotin/metabolism
- Gap Junctions/physiology*
- Gap Junctions/ultrastructure
- Feedback, Physiological/physiology
- Microinjections
- Patch-Clamp Techniques
- Biophysics
- Green Fluorescent Proteins/genetics
- Green Fluorescent Proteins/metabolism*
- Retinal Horizontal Cells/classification
- Retinal Horizontal Cells/physiology*
- Retinal Horizontal Cells/ultrastructure
- Microscopy, Confocal
- Xenopus laevis
- Connexins/genetics
- Connexins/metabolism
- Transduction, Genetic
- Electric Stimulation
- Photoreceptor Cells, Vertebrate/classification
- Photoreceptor Cells, Vertebrate/physiology*
- Photoreceptor Cells, Vertebrate/ultrastructure
- Analysis of Variance
- Animals
- Animals, Genetically Modified
- Zebrafish
- Membrane Potentials/physiology*
- Retina/cytology*
- PubMed
- 27707811 Full text @ J. Neurophysiol.
Citation
Klaassen, L.J., de Graaff, W., Van Asselt, J.B., Klooster, J., Kamermans, M. (2016) Specific connectivity between photoreceptors and horizontal cells in the zebrafish retina. Journal of neurophysiology. 116(6):2799-2814.
Abstract
The functional and morphological connectivity between various horizontal cell (HC) types (H1, H2, H3 and H4), and photoreceptors was studied in zebrafish retina. Since HCs are strongly coupled by gap-junctions and feedback from HCs to photoreceptors strongly depends on connexin (Cx) hemichannels we characterized the various HC Cxs (Cx52.6, Cx52.7, Cx52.9 and Cx55.5) in Xenopus oocytes. All Cxs formed hemichannels which were conducting at physiological membrane potentials. The Cx hemichannels differed in kinetic properties and voltage dependence, allowing for specific tuning of the coupling of HCs and the feedback signal from HCs to cones. The morphological connectivity between the HC layers and the cones was determined next. We used zebrafish expressing GFP under the control of Cx promoters. We found that all HCs showed Cx55.5 promoter activity. Cx52.7 promoter activity was exclusively present in H4 cells while Cx52.9 promoter activity occurred only in H1 cells. Cx52.6 promoter activity was present in H4 cells and in the ventral quadrant of the retina also in H1 cells. Finally we determined the spectral sensitivities of the HC layers. Three response types were found. Monophasic responses were generated by HCs that contacted all cones (H1 cells), biphasic responses were generated by HCs that contacted M-, S- and UV-cones (H2 cells), and triphasic responses were generated by HCs that contacted either S- and UV-cones (H3 cells) or rods and UV-cones (H4 cells). Electronmicroscopy confirms that H4 cells innervate cones. This indicates that rod driven HCs process spectral information during photopic and luminance information during scotopic conditions.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping