Abstract
Purpose :
Mice, a dichromatic mammalian distinct from humans, exhibit poor visual acuity. However, few studies have revealed the extracellular bioelectrical activity under light stimulation specific to the photoreceptors physiology in mice retina. This study sought to more precisely characterize the intrinsic function of rod- and/or cone-mediated vision using light sources within the wavelength range preferred by the mouse retina.
Methods :
For the precise evaluation of rod and/or cone function, ERG recordings were systematically performed on pigmented (C57/BL6) and albino mice (balb/C), employing meticulously designed light stimulation conditions such as varying the wavelength, exposure time, and frequency. As experiments to explore the possibility of early detecting in rod and/or cone degeneration, RT-qPCR, Western Blotting method, immunohistochemistry were proceeded and analyzed in the NaIO3-injected injury model.
Results :
First, in order to investigate how ERG correspond photoreceptors structural difference such as the vast gap in S-opsin expression pattern between the pigmented (C57/BL6) and albino mice (balb/C), test of both strains and comparative analysis were performed under the white-and blue-light stimuli, respctively. C57 mice, known to be more resistant to light exposure, showed more blue-susceptive enhancing effects and stronger photopic vision than albino ones. In the blue flash-evoked ERG conducted from C57 mice, a decrease in response threshold and an increase in ERG efficiency for intensity were confirmed in both scotopic and photopic vision. The flicker ERG results obtained by varying the frequncy of blue flash showed that the blue stimulus was effective in discriminating rod-and cone-driven signal (in the dark-adapted 10Hz condition), and in detecting fast rod response. Moreover, the discerned patterns of acute dysfunction in both rod and cone photoreceptors observed in the NaIO3-injected injury model, significantly mathched with the corresponding patterns identified through RT-qPCR, WB, and IHC.
Conclusions :
The present study suggests that blue light might be a key factor to detect intrinsic temporal property and visual acuity in both scotopic and photopic function in mice retina.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.