As soon as you open your eyes in the morning, the cells of your retina start sending frantic messages to your brain. “It’s sunny today! That toast looks done!” One set of cells in particular, the high-resolution retinal cells, are constantly working to give your brain the most detailed, up-to-date picture of your surroundings. But in a mouse’s eye, researchers have recently discovered, the high-resolution cells seem to be on vacation.
That is, until a predator flies by.
To get a sense of how mice use their high-resolution cells, the researchers had first strapped a camera to a rat’s head and let it run around an enclosure. Then they projected this video of what a rodent sees in its daily life onto mouse retinas, while monitoring the cells’ electrical responses. They were surprised to find that while many of the retinal cells reacted to the images, the high-resolution ones remained unresponsive.