Bipolar cell-photoreceptor connectivity in the zebrafish (Danio rerio) retina
- Authors
- Li, Y.N., and Dowling, J.E.
- ID
- ZDB-PUB-120822-35
- Date
- 2012
- Source
- The Journal of comparative neurology 520(16): 3786-3802 (Journal)
- Registered Authors
- Dowling, John E.
- Keywords
- Dil, photoreceptors, bipolar cells, retina, connectivity, zebrafish
- MeSH Terms
-
- Animals
- Animals, Genetically Modified
- Microscopy, Confocal
- Photoreceptor Cells, Vertebrate/ultrastructure*
- Retinal Bipolar Cells/ultrastructure*
- Zebrafish/anatomy & histology*
- PubMed
- 22907678 Full text @ J. Comp. Neurol.
Bipolar cells convey luminance, spatial and color information from photoreceptors to amacrine and ganglion cells. We studied the photoreceptor connectivity of 321 bipolar cells in the adult zebrafish retina. DiI was inserted into whole-mounted transgenic zebrafish retinas to label bipolar cells. The photoreceptors that connect to these DiI-labeled cells were identified by transgenic fluorescence or their positions relative to the fluorescent cones, as cones are arranged in a highly-ordered mosaic: rows of alternating blue- (B) and ultraviolet-sensitive (UV) single cones alternate with rows of red- (R) and green-sensitive (G) double cones. Rod terminals intersperse among cone terminals. As many as 18 connectivity subtypes were observed, 9 of which – G, GBUV, RG, RGB, RGBUV, RGRod, RGBRod, RGBUVRod and RRod bipolar cells – accounted for 96% of the population. Based on their axonal terminal stratification, these bipolar cells could be further sub-divided into ON, OFF, and ON-OFF cells. The dendritic spread size, soma depth and size, and photoreceptor connections of the 308 bipolar cells within the 9 common connectivity subtypes were determined, and their dendritic tree morphologies and axonal stratification patterns compared. We found that bipolar cells with the same axonal stratification patterns could have heterogeneous photoreceptor connectivity whereas bipolar cells with the same dendritic tree morphology usually had the same photoreceptor connectivity, although their axons might stratify on different levels.