http://phys.org/ en-us Phys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine. (Phys.org)—In a primitive marine organism, MBL scientists find photosensitive cells that may be ancestral to the "circadian receptors" in the mammalian retina. http://phys.org/news279395373.html Biology Wed, 06 Feb 2013 17:49:54 EST news279395373 The sensory cells in the retina of the mammalian eye convert light stimuli into electrical signals and transmit them via downstream interneurons to the retinal ganglion cells which, in turn, forward them to the brain. The interneurons are connected to each other in such a way that the individual ganglion cells receive visual information from a circular area of the visual field known as the receptive field. Some ganglion cells are only activated, for example, when light falls on the centre of their receptive fields and the edge remains dark (ON cells). The opposite is the case for other ganglion cells (OFF cells). And there are also ganglion cells that are activated by light that sweeps across their receptive fields in a particular direction; motion in the opposite (null-) direction inhibits activation. http://phys.org/news218899479.html Medicine & Health Wed, 09 Mar 2011 13:24:56 EST news218899479 Using a method that involved the clustering of samples that showed similarity in expression profiles, Jackson Laboratory researchers were able to identify molecular signatures of early events in glaucoma progression -- events that were detectable before there was morphological evidence of damage. http://phys.org/news218724062.html Medicine & Health Mon, 07 Mar 2011 13:40:01 EST news218724062 A paper published online on January 10 in the Journal of Experimental Medicine reports that retinal ganglion cells—neurons in the eye—are rescued by immune cells that infiltrate the mouse retina after eye injury. http://phys.org/news213884632.html Medicine & Health Mon, 10 Jan 2011 12:40:01 EST news213884632 Better known as the light sensor that sets the body's biological clock, melanopsin also plays an important role in vision: Via its messengers-so-called melanopsin-expressing retinal ganglion cells, or mRGCs-it forwards information about the brightness of incoming light directly to conventional visual centers in the brain, reports an international collaboration of scientists in this week's issue of PLoS Biology. http://phys.org/news210965726.html Biology Tue, 07 Dec 2010 18:10:01 EST news210965726 (PhysOrg.com) -- Using a sophisticated neural recording system developed by physicists at UC Santa Cruz, researchers were able to trace for the first time the neural circuitry that connects individual photoreceptors with retinal ganglion cells, the neurons that carry visual signals from the eye to the brain. http://phys.org/news206091801.html Medicine & Health Tue, 12 Oct 2010 08:43:46 EST news206091801 By comparing a clearly defined visual input with the electrical output of the retina, researchers at the Salk Institute for Biological Studies were able to trace for the first time the neuronal circuitry that connects individual photoreceptors with retinal ganglion cells, the neurons that carry visuals signals from the eye to the brain. http://phys.org/news205589653.html Medicine & Health Wed, 06 Oct 2010 13:15:34 EST news205589653 Physicists and neuroscientists from the University of Pennsylvania have linked the cell structure of the retina to the light and dark contrasts of the natural world, demonstrating the likelihood that the neural pathways humans use for seeing are adapted to best capture the world around us. http://phys.org/news205500080.html Medicine & Health Tue, 05 Oct 2010 12:21:32 EST news205500080 It would make the perfect question for the popular television show "Are You Smarter than a 5th Grader:" What parts of the eye allow us to see? http://phys.org/news198342777.html Medicine & Health Wed, 14 Jul 2010 16:13:24 EST news198342777 Brain and spinal-cord injuries typically leave people with permanent impairment because the injured nerve fibers (axons) cannot regrow. A study from Children's Hospital Boston, published in the December 10 issue of the journal Neuron, shows that axons can regenerate vigorously in a mouse model when a gene that suppresses natural growth factors is deleted. http://phys.org/news179584849.html Medicine & Health Wed, 09 Dec 2009 12:50:01 EST news179584849 Scientists at the California Institute of Technology (Caltech) have created a remote-controlled robot that is able to simulate the "visual" experience of a blind person who has been implanted with a visual prosthesis, such as an artificial retina. An artificial retina consists of a silicon chip studded with a varying number of electrodes that directly stimulate retinal nerve cells. It is hoped that this approach may one day give blind persons the freedom of independent mobility. http://phys.org/news175183657.html Technology Mon, 19 Oct 2009 15:08:24 EST news175183657 About 1.25 million neurons in the retina -- each of which views the world only through a small jagged window called a receptive field -- collectively form the seamless picture we rely on to navigate our environment. Receptive fields fit together like pieces of a puzzle, preventing "blind spots" and excessive overlap that could blur our perception of the world, according to researchers at the Salk Institute for Biological Studies. http://phys.org/news158303038.html Medicine & Health Tue, 07 Apr 2009 06:04:41 EST news158303038 Although scientists know progressive degeneration of retinal ganglion cells and their axons is the primary cause of glaucoma, researchers have yet to identify a way to stop or prevent the degeneration. http://phys.org/news155395473.html Medicine & Health Wed, 04 Mar 2009 13:25:04 EST news155395473