ZFIN ID: ZDB-PUB-171113-4
Connectivity of cone photoreceptor telodendria in the zebrafish retina
Noel, N.C.L., Allison, W.T.
Date: 2017
Source: The Journal of comparative neurology   526(4): 609-625 (Journal)
Registered Authors: Allison, Ted
Keywords: RRID: ZDB-ALT-60425-3, RRID: ZDB-ALT-60830-4, RRID: ZDB-ALT-60901-10, RRID: ZDB-ALT-60901-14, RRID: ZDB-ALT-71101-1, RRID: ZDB-ALT-71101-2, RRID:ZDB-ALT-80227-1, RRID:ZDB-ALT-80920-1, RRID:ZFIN_ZDB-ALT-30819-1, RRID:ZIRC_ZL1515, cell ablation, connectomics, connexin, dark adaptation, gap junction, nitroreductase, photoreceptors, retina, retina mosaic, synapse, zebrafish
MeSH Terms:
  • Animals
  • Animals, Genetically Modified
  • Larva/cytology
  • Larva/growth & development
  • Retinal Cone Photoreceptor Cells/cytology*
  • Synapses
  • Visual Pathways/cytology
  • Visual Pathways/growth & development
  • Zebrafish/anatomy & histology*
  • Zebrafish/growth & development
PubMed: 29127712 Full text @ J. Comp. Neurol.
The connectivity amongst photoreceptors is critical to their function, as it underpins lateral inhibition and effective translation of stimuli into neural signals. Despite much work characterizing second-order interneurons in the outer retina, the synapses directly connecting photoreceptors have often been overlooked. Telodendria are fine processes that connect photoreceptor pedicles. They have been observed in diverse vertebrate groups, yet their roles in vision remain speculative. Here, we visualize telodendria via fluorescent protein expression in photoreceptor subtypes. We characterized short wavelength cone telodendria in adult and larval zebrafish retina. Additionally, in the larval retina, we investigated rod telodendria and UV cone telodendria in mutant and transgenic retinas with altered complements of cone types. In the adult retina, telodendria are twice as abundant and branch almost twice as often on blue cones compared to UV cones. Pedicles of neighbouring UV and blue cones typically converge into contiguous pairs, despite the regular spacing of their cell bodies. In contrast to adults, larval UV cone telodendria are more numerous (1.3 times) than blue cone telodendria. UV cone telodendria are not detectably affected by ablation of blue cones, and are reduced 2-fold in mutant larval retina with few UV cones. We thus saw no evidence that telodendria increase in number in the absence of their typical cellular neighbours. We also found that larval rod telodendria are less abundant than short wavelength cone telodendria. In summary, we describe the development and morphology of zebrafish photoreceptor synaptic connectivity towards appreciating the function of telodendria in visual signal processing. This article is protected by copyright. All rights reserved.