Abstract
Purpose :
Zebrafish are being used more frequently for many different research projects and goals. Many studies examining their utility for vision research rely on the OKR to assess spatial resolution, temporal resolution, and contrast sensitivity. Examining other aspects such as color vision have relied more heavily on the ERG and behavioral maze experiments or been focused just on larval zebrafish. We wanted to test the visual response of adult zebrafish to different wavelengths of light using the OKR. Because zebrafish are tetrachromatic we chose lights that are red, green, blue, and ultraviolet.
Methods :
Adult zebrafish, aged 9-18 months, were maintained under standard conditions. Two strains of fish, AB and casper, were used for analysis. The fish were initially screened for visual anomalies such as cataracts and their spatial acuity threshold (visual acuity) was measured using the optokinetic response (OKR) under photopic conditions. We subsequently measured their visual acuity using red, green, blue, and ultraviolet light to illuminate the gratings. Each eye was measured independently and then together. Repeated measure ANOVA was then used to compare the responses relative to the strain and normal visual acuities.
Results :
No difference was found between either the AB or casper fish visual acuities. Comparing the different light conditions to their normal visual acuities, the visual acuity recorded using blue light was significantly reduced (p=0.0068 n=10). Other factors such as binocular interactions appeared to be unchanged during the several illumination protocols.
Conclusions :
Visual acuity in adult zebrafish is affected by the wavelength used. As with humans, the fish respond poorly to blue light. Interestingly, the ultraviolet light did not have a significant effect on visual performance. Additional color vision testing using the OKR may provide insight into the vision of zebrafish and aid in our use of this animal system to model human vision.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.