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Retinal Cone Photoreceptor Cells: Photosensitive afferent neurons located primarily within the Fovea centralis of the Macula lutea. There are three major types of cone cells (red, blue, and green) with photopigments of different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.

Imaging Ca2+ Dynamics in Cone Photoreceptor Axon Terminals of the Mouse Retina

1Institute for Ophthalmic Research, University of Tübingen, 2Graduate School of Cellular & Molecular Neuroscience, University of Tübingen, 3Bernstein Centre for Computational Neuroscience, University of Tübingen, 4Molecular Genetics Laboratory, University of Tübingen, 5Centre for Ophthalmology, University of Tübingen

JoVE 52588

 Neuroscience

The Retina

JoVE 10857

The retina is a layer of nervous tissue at the back of the eye that transduces light into neural signals. This process, called phototransduction, is carried out by rod and cone photoreceptor cells in the back of the retina.

Photoreceptors have outer segments with stacks of membranous disks that contain photopigment molecules—such as rhodopsin in rods. The photopigments absorb light, triggering a cascade of molecular events that results in the cell becoming hyperpolarized (with a more negative membrane potential) relative to when it is in the dark. This hyperpolarization decreases neurotransmitter release. Thus, unlike stimuli for most other sensory neurons, light induces a reduction in neurotransmitter release from photoreceptors. Although rods and cones both detect light, they play distinct roles in vision. Rods are highly sensitive to light, and therefore predominate in low-light conditions, such as at night. Cones are less sensitive and are used for most daytime vision. Cones are densely concentrated in the fovea—a small depression near the center of the retina that contains very few rods—and provide a high level of visual acuity in the area where the eye is focused. Cones also convey color information, because the different types—S (short), M (medium), and L (long) in humans—maximally absorb different wa

 Core: Biology

Vision

JoVE 10858

Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed. Light is absorbed by the rod and cone photoreceptor cells at the back of the retina, causing a decrease in their rate of neurotransmitter release. In addition to detecting photons of light, color information is also encoded here, since different types of cones respond maximally to different wavelengths of light. The photoreceptors then send visual information to bipolar cells near the middle of the retina, which is followed by projection to ganglion cells at the front of the retina. Horizontal and amacrine cells mediate lateral interactions between these cell types, integrating information from multiple photoreceptors. This integration aids in the initial processing of visual information, such as detecting simple features, like edges. Along with glial cells, the axons of the retinal ganglion cells make up the optic nerve, which transmits visual information to the brain. The optic nerve partially cro

 Core: Biology

Ultrahigh Resolution Mouse Optical Coherence Tomography to Aid Intraocular Injection in Retinal Gene Therapy Research

1Research Service, VA Western New York Healthcare System, 2Department of Ophthalmology, (Ross Eye Institute), Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- SUNY, 3Pharmacology/Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- SUNY, 4Physiology/Biophysics, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- SUNY, 5Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo- SUNY, 6The RNA Institute, University at Buffalo- SUNY, 7The SUNY Eye Institute

JoVE 55894

 Medicine
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