A Selective Color-Opponent Pathway in the Mouse Retina


May 14, 2014 - 1:00pm
NW 243
About the Speaker
Max Joesch (Meister Lab)

In the mammalian retina, rods and cones play very different roles. Rods are thought to operate in very dim light, and feed their signal into the cone pathways at the level of bipolar cells. Cones operate in bright light and are responsible for color vision. Here we describe a circuit in the mouse retina that violates all these principles. A specific type of retinal ganglion cell J-RGC [1] was found to have color-opponent responses: OFF to UV light, ON to green light. Although the mouse retina contains a green cone, the ON response instead originates in rods. Rods and cones both contribute to the response over a wide range of light levels. Remarkably the rod signal is antagonistic to that from cones, which shows that rods have a private synaptic pathway leading through an OFF-bipolar and amacrine cells all the way to ganglion cells. The results reveal an unexpected variety by which known neural cell types are combined into circuits and uncover a circuit mechanism by which mice can detect color information. 

[1] Kim et al. Molecular identification of a retinal cell type that responds to upward motion. Nature 2008.