Noninvasive Imaging of Cone Ablation and Regeneration in Zebrafish. Transl Vis Sci Technol 2020 Sep;9(10):18
Date
09/29/2020Pubmed ID
32983626Pubmed Central ID
PMC7500127DOI
10.1167/tvst.9.10.18Scopus ID
2-s2.0-85091664660 (requires institutional sign-in at Scopus site) 5 CitationsAbstract
PURPOSE: To observe and characterize cone degeneration and regeneration in a selective metronidazole-mediated ablation model of ultraviolet-sensitive (UV) cones in zebrafish using in vivo optical coherence tomography (OCT) imaging.
METHODS: Twenty-six sws1:nfsB-mCherry;sws2:eGFP zebrafish were imaged with OCT, treated with metronidazole to selectively kill UV cones, and imaged at 1, 3, 7, 14, 28, or 56 days after ablation. Regions 200 × 200 µm were cropped from volume OCT scans to count individual UV cones before and after ablation. Fish eyes were fixed, and immunofluorescence staining was used to corroborate cone density measured from OCT and to track monocyte response.
RESULTS: Histology shows significant loss of UV cones after metronidazole treatment with a slight increase in observable blue cone density one day after treatment (Kruskal, Wallis, P = 0.0061) and no significant change in blue cones at all other timepoints. Regenerated UV cones measured from OCT show significantly lower density than pre-cone-ablation at 14, 28, and 56 days after ablation (analysis of variance, P < 0.01, P < 0.0001, P < 0.0001, respectively, 15.9% of expected nonablated levels). Histology shows significant changes to monocyte morphology (mixed-effects analysis, P < 0.0001) and retinal position (mixed-effects analysis, P < 0.0001).
CONCLUSIONS: OCT can be used to observe loss of individual cones selectively ablated by metronidazole prodrug activation and to quantify UV cone loss and regeneration in zebrafish. OCT images also show transient changes to the blue cone mosaic and inner retinal layers that occur concomitantly with selective UV cone ablation.
TRANSLATIONAL RELEVANCE: Profiling cone degeneration and regeneration using in vivo imaging enables experiments that may lead to a better understanding of cone regeneration in vertebrates.
Author List
Huckenpahler AL, Lookfong NA, Warr E, Heffernan E, Carroll J, Collery RFAuthors
Joseph J. Carroll PhD Director, Professor in the Ophthalmology and Visual Sciences department at Medical College of WisconsinRoss F. Collery PhD Assistant Professor in the Ophthalmology and Visual Sciences department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsDiagnostic Tests, Routine
Regeneration
Retinal Cone Photoreceptor Cells
Tomography, Optical Coherence
Zebrafish
