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Amacrine Cells: Interneurons of the vertebrate Retina. They integrate, modulate, and interpose a temporal domain in the visual message presented to the Retinal ganglion cells, with which they synapse in the inner plexiform layer.

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: Sensory Systems

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: Sensory Systems

Isolation of Primary Murine Retinal Ganglion Cells (RGCs) by Flow Cytometry

1Department of Ophthalmology, Hamilton Eye Institute, University of Tennessee Health Science Center, 2Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, 3Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, 4Department of Pharmaceutical Sciences, University of Tennessee Health Science Center

JoVE 55785

 Bioengineering

Vibratome Sectioning Mouse Retina to Prepare Photoreceptor Cultures

1Department of Genetics, UMR_S 968, Institut de la Vision, 2Department of Visual Information, UMR_S 968, Institut de la Vision, 3Exploratory Team, UMR_S 968, Institut de la Vision, 4Sorbonne Universités, Paris 06, UMR_S 968, Institut de la Vision, 5INSERM, U968, Institut de la Vision, 6CNRS, UMR_7210, Institut de la Vision

JoVE 51954

 Neuroscience

Immunohistochemical and Calcium Imaging Methods in Wholemount Rat Retina

1Department of Neurobiology, University of California, Los Angeles, 2Veterans Administration Greater Los Angeles Healthcare System, 3Departments of Physiology & Biophysics and Ophthalmology & Visual Sciences, Dalhousie University, 4Departments of Neurobiology and Medicine, Jules Stein Eye Institute, CURE-Digestive Diseases Research Center, David Geffen School of Medicine, University of California, Los Angeles

JoVE 51396

 Neuroscience

Techniques for Processing Eyes Implanted With a Retinal Prosthesis for Localized Histopathological Analysis

1Bionics Institute, 2Department of Anatomical Pathology, St Vincent's Hospital Melbourne, 3Department of Pathology, University of Melbourne, 4Medical Bionics Department, University of Melbourne

JoVE 50411

 Medicine
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