Effects of restricted spectral rearing on the development of zebrafish retinal physiology.

Research has shown that rearing in abnormal lighting environments affects both visual behavior and retinal physiology in zebrafish larvae. These studies, however, used only constant dark and constant white light as the experimental rearing conditions. This study assessed the effects of rearing larvae in restricted spectral lighting environments on zebrafish retinal physiology. Larvae were reared in one of seven different lighting environments: cyclic white light (control group), constant blue light, constant green light, constant orange light, cyclic blue light, cyclic green light, and cyclic orange light. Assessment of retinal physiology was done using the electroretinogram (ERG). Results showed that rearing larvae in constant light conditions caused deficits in sensitivity to ultraviolet- and short-wavelength stimuli, but had little effect on sensitivity to middle- and long-wavelength stimuli. Rearing larvae in cyclic light did not cause differences in sensitivity to middle- and long-wavelength stimuli, but did cause extreme deficits in sensitivity to ultraviolet- and short-wavelength stimuli in the cyclic green and orange light-rearing conditions. Sensitivity of the cyclic blue light-rearing group was similar to the control group to stimuli of all wavelengths. The results support the notion that the light-rearing environment impacts the development of the ultraviolet- and short-wavelength cone mechanisms but has little impact on the development of the middle- and long-wavelength cone mechanisms; these effects coincide with the development of the various cone types. This study supports the notion that the zebrafish is a viable model for studying the effects of the lighting environment on visual development.