Towards in vivo imaging of the mouse cone photoreceptors (Conference Presentation)

Vision is the most important sense organ of human, more than 80% of the information from outside world is acquired by vision. Vision starts at the photoreceptors in the retina capturing the visible light photons. There are two general types of photoreceptors, called rods and cones. Rods allow us to see in dim and dark light, cones allow us to perceive fine visual detail and color. To understand physiology of cones, researchers developed many model organisms that allow them to study in details different aspects of photoreceptors function. Specifically, mice play a central role in basic vision science research. However, one should keep in mind that mice have rod dominant retinas which is different from human cone dominant retinas near fovea. As one of the consequence in vivo imaging of cones in humans is relatively easy in periphery, and cone mosaic was the first cellular structure that was reported to be seen by optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO), especially with implementation of adaptive optics (AO)[1]. However, just recently researchers started to visualize human rods which are smaller than cones [2, 3]. In case of mouse retinal imaging, it is quite the opposite situation. There have been recent reports of imaging rods mosaic [4-6], but up to date no reports on identifying cones in the images. Given that the cones are twice as big as rods in mice, it is very interesting why one can visualize rods but cannot visualize cones.