optic nerve
Snapshots of Life: A Colorful Look Inside the Retina
Posted on by Dr. Francis Collins
Credit: Amy Robinson, Alex Norton, William Silversmith, Jinseop Kim, Kisuk Lee, Aleks Zlasteski, Matt Green, Matthew Balkam, Rachel Prentki, Marissa Sorek, Celia David, Devon Jones, and Doug Bland, Massachusetts Institute of Technology, Cambridge, MA; Sebastian Seung, Princeton University, Princeton, NJ
This eerie scene might bring back memories of the computer-generated alien war machines from Steven Spielberg’s War of the Worlds thriller. But what you’re seeing is a computer-generated depiction of a quite different world—the world inside the retina, the light-sensitive tissue that lines the back of the eye. The stilt-legged “creatures” are actually ganglion nerve cells, and what appears to be their long “noses” are fibers that will eventually converge to form the optic nerve that relays visual signals to the brain. The dense, multi-colored mat near the bottom of the image is a region where the ganglia and other types of retinal cells interact to convey visual information.
What I find particularly interesting about this image is that it was produced through the joint efforts of people who played EyeWire, an internet crowdsourcing game developed in the lab of computational neuroscientist Sebastian Seung, now at Princeton University in New Jersey. Seung and his colleagues created EyeWire using a series of high-resolution microscopic images of the mouse retina, which were digitized into 3D cubes containing dense skeins of branching nerve fibers. It’s at this point where the crowdsourcing came in. Online gamers—most of whom aren’t scientists— volunteered for a challenge that involved mapping the 3D structure of individual nerve cells within these 3D cubes. Players literally colored-in the interiors of the cells and progressively traced their long extensions across the image to distinguish them from their neighbors. Sounds easy, but the branches are exceedingly thin and difficult to follow.
Snapshots of Life: Seeing, from Eye to Brain
Posted on by Dr. Francis Collins
| Credit: Xueting Luo and Kevin Park, University of Miami |
Fasten your seat belts! We’re going to fly through the brain of a mouse. Our tour guide is Kevin Park, an NIH-funded neuroscientist at the University of Miami, who has developed a unique method to visualize neurons in an intact brain. He’s going to give us a rare close-up of the retinal ganglion cells that carry information from the eye to the brain, where the light signals are decoded and translated.
To make this movie, Park has injected a fluorescent dye into the mouse eye; it is taken up by the retinal cells and traces out the nerve pathways from the optic nerve into the brain.
