They knew that mice possessed light-sensitive proteins called opsins that allowed them to detect a limited range of colors. But as they investigated the role M5 cells played in this, Stabio discovered that the mice also had neurons that could compare signals from the different opsins and then send those color signals to the brain for interpretation.
“We are the first to discover this particular color vision circuit in mice,” Stabio said. “We knew they had opsins but we didn’t know they possessed the other two requirements for color vision.”
Stabio’s work focuses primarily on the cells and circuits of the retina, including a group called intrinsically photosensitive retinal ganglion cells or ipRGCs which includes the M5. These cells are primarily involved in a kind of vision known as non-image forming vision.
The discovery that color vision in mice is far more complex than originally thought, opens the door to experiments that could potentially lead to new treatments for humans. The study was published in December in the journal Neuron.