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This story is from the category Sensors
Date posted: 09/05/2010 The eyes are marvelous instruments for converting outside reality into images lodged inside our brains. A new study of the retina, the light-sensitive region at the back of the eye, solves a mystery as to why the images we see are so sharp. The light-sensitive cells in the retina -- rod-shaped cells, which can process very low levels of light, and cone-shaped cells, responsible for perceiving color -- pass their electrical signals along to neurons, lengthy cells which, when bundled together as the optic nerve, carry visual information deep into the brain. Strangely, the neurons which govern this delicate process lie in front of -- not behind -- the receiving rod and cone cells. Even though these neurons are transparent to light, their wrinkled shape distorts the light as it passes through on its way toward the rods and cones. Why aren't the neurons underneath the light-sensitive cells, where they won?t distort the incoming image of the outside world? The mystery has now been solved by explaining the role of glial cells. Glial cells perform a number of roles around the body, such as bringing nutrients to other cells or holding them in place. This is especially important for glial cells in the brain; they are sometimes referred to as the ?glue" of the brain. See the full Story via external site: www.physorg.com Most recent stories in this category (Sensors): 14/06/2013: Autonomous energy-scavenging micro devices will test water quality, monitor bridges, more |
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