Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.
Specialized PHOTOTRANSDUCTION neurons in the vertebrates, such as the RETINAL ROD CELLS and the RETINAL CONE CELLS. Non-visual photoreceptor neurons have been reported in the deep brain, the PINEAL GLAND and organs of the circadian system.
Specialized cells in the invertebrates that detect and transduce light. They are predominantly rhabdomeric with an array of photosensitive microvilli. Illumination depolarizes invertebrate photoreceptors by stimulating Na+ influx across the plasma membrane.
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) whose photopigments have different spectral sensitivity curves. Retinal cone cells operate in daylight vision (at photopic intensities) providing color recognition and central visual acuity.
A retrogressive pathological change in the retina, focal or generalized, caused by genetic defects, inflammation, trauma, vascular disease, or aging. Degeneration affecting predominantly the macula lutea of the retina is MACULAR DEGENERATION. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p304)
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
A purplish-red, light-sensitive pigment found in RETINAL ROD CELLS of most vertebrates. It is a complex consisting of a molecule of ROD OPSIN and a molecule of 11-cis retinal (RETINALDEHYDE). Rhodopsin exhibits peak absorption wavelength at about 500 nm.
Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
Photosensitive afferent neurons located in the peripheral retina, with their density increases radially away from the FOVEA CENTRALIS. Being much more sensitive to light than the RETINAL CONE CELLS, the rod cells are responsible for twilight vision (at scotopic intensities) as well as peripheral vision, but provide no color discrimination.
The portion of a retinal rod cell situated between the ROD INNER SEGMENT and the RETINAL PIGMENT EPITHELIUM. It contains a stack of photosensitive disk membranes laden with RHODOPSIN.
Recording of electric potentials in the retina after stimulation by light.
The light sensitive outer portion of a retinal rod or a cone photoreceptor cell. The outer segment contains a stack of disk membranes laden with photoreceptive pigments (RETINAL PIGMENTS). The outer segment is connected to the inner segment by a PHOTORECEPTOR CONNECTING CILIUM.
The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.
Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.
Hereditary, progressive degeneration of the neuroepithelium of the retina characterized by night blindness and progressive contraction of the visual field.
The conversion of absorbed light energy into molecular signals.
Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells.
A 48-Kd protein of the outer segment of the retinal rods and a component of the phototransduction cascade. Arrestin quenches G-protein activation by binding to phosphorylated photolyzed rhodopsin. Arrestin causes experimental autoimmune uveitis when injected into laboratory animals.
Photosensitive proteins in the membranes of PHOTORECEPTOR CELLS such as the rods and the cones. Opsins have varied light absorption properties and are members of the G-PROTEIN-COUPLED RECEPTORS family. Their ligands are VITAMIN A-based chromophores.
The bridge between the inner and the outer segments of a retinal rod or a cone photoreceptor cell. Through it, proteins synthesized in the inner segment are transported to the outer segment.
The organ of sight constituting a pair of globular organs made up of a three-layered roughly spherical structure specialized for receiving and responding to light.
A heterotrimeric GTP-binding protein that mediates the light activation signal from photolyzed rhodopsin to cyclic GMP phosphodiesterase and is pivotal in the visual excitation process. Activation of rhodopsin on the outer membrane of rod and cone cells causes GTP to bind to transducin followed by dissociation of the alpha subunit-GTP complex from the beta/gamma subunits of transducin. The alpha subunit-GTP complex activates the cyclic GMP phosphodiesterase which catalyzes the hydrolysis of cyclic GMP to 5'-GMP. This leads to closure of the sodium and calcium channels and therefore hyperpolarization of the rod cells. EC 3.6.1.-.
Experimentally produced harmful effects of ionizing or non-ionizing RADIATION in CHORDATA animals.
The layer of pigment-containing epithelial cells in the RETINA; the CILIARY BODY; and the IRIS in the eye.
A cyclic nucleotide phosphodiesterase subfamily that is highly specific for CYCLIC GMP. It is found predominantly in the outer segment PHOTORECEPTOR CELLS of the RETINA. It is comprised of two catalytic subunits, referred to as alpha and beta, that form a dimer. In addition two regulatory subunits, referred to as gamma and delta, modulate the activity and localization of the enzyme.
A form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody. (From Bennington, Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984)
A neuronal calcium-sensor protein that is found in ROD PHOTORECEPTORS and CONE PHOTORECEPTORS. It interacts with G-PROTEIN-COUPLED RECEPTOR KINASE 1 in a Ca2+ dependent manner and plays an important role in PHOTOTRANSDUCTION.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
Separation of the inner layers of the retina (neural retina) from the pigment epithelium. Retinal detachment occurs more commonly in men than in women, in eyes with degenerative myopia, in aging and in aphakia. It may occur after an uncomplicated cataract extraction, but it is seen more often if vitreous humor has been lost during surgery. (Dorland, 27th ed; Newell, Ophthalmology: Principles and Concepts, 7th ed, p310-12).
The adjustment of the eye to variations in the intensity of light. Light adaptation is the adjustment of the eye when the light threshold is increased; DARK ADAPTATION when the light is greatly reduced. (From Cline et al., Dictionary of Visual Science, 4th ed)
Plant proteins that mediate LIGHT SIGNAL TRANSDUCTION. They are involved in PHOTOTROPISM and other light adaption responses during plant growth and development . They include the phototropins, phytochromes (PHYTOCHROME), and members of the ubiquitous cryptochrome family.
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips (outer segments) of the RETINAL PHOTORECEPTOR CELLS. These epithelial cells are macroglia that perform essential functions for the photoreceptor cells, such as in nutrient transport, phagocytosis of the shed photoreceptor membranes, and ensuring retinal attachment.
Rats bearing mutant genes which are phenotypically expressed in the animals.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
A neuronal calcium-sensor protein that was initially found in the NEURONS of the HIPPOCAMPUS. It interacts with NEURONAL APOPTOSIS-INHIBITORY PROTEIN.
The absence of light.
An arthropod subclass (Xiphosura) comprising the North American (Limulus) and Asiatic (Tachypleus) genera of horseshoe crabs.
A PROTEIN-SERINE-THREONINE KINASE that is found in PHOTORECEPTOR CELLS. It mediates light-dependent PHOSPHORYLATION of RHODOPSIN and plays an important role in PHOTOTRANSDUCTION.
A light-sensitive neuroendocrine organ attached to the roof of the THIRD VENTRICLE of the brain. The pineal gland secretes MELATONIN, other BIOGENIC AMINES and NEUROPEPTIDES.
Light sensory organ in ARTHROPODS consisting of a large number of ommatidia, each functioning as an independent photoreceptor unit.
An in situ method for detecting areas of DNA which are nicked during APOPTOSIS. Terminal deoxynucleotidyl transferase is used to add labeled dUTP, in a template-independent manner, to the 3 prime OH ends of either single- or double-stranded DNA. The terminal deoxynucleotidyl transferase nick end labeling, or TUNEL, assay labels apoptosis on a single-cell level, making it more sensitive than agarose gel electrophoresis for analysis of DNA FRAGMENTATION.
Enzymes that catalyze the hydrolysis of cyclic GMP to yield guanosine-5'-phosphate.
Type III intermediate filament proteins expressed mainly in neurons of the peripheral and CENTRAL NERVOUS SYSTEMS. Peripherins are implicated in neurite elongation during development and axonal regeneration after injury.
Neuronal calcium sensor proteins that regulate the activation of membrane-bound GUANYLATE CYCLASE. They are primarily expressed in the RETINA where they play an important role in PHOTOTRANSDUCTION.
Enzymes that catalyze the rearrangement of geometry about double bonds. EC 5.2.
Processes and properties of the EYE as a whole or of any of its parts.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
INTERNEURONS of the vertebrate RETINA containing two processes. They receive inputs from the RETINAL PHOTORECEPTOR CELLS and send outputs to the RETINAL GANGLION CELLS. The bipolar cells also make lateral connections in the retina with the RETINAL HORIZONTAL CELLS and with the AMACRINE CELLS.
Light absorbing proteins and protein prosthetic groups found in certain microorganisms. Some microbial photoreceptors initiate specific chemical reactions which signal a change in the environment, while others generate energy by pumping specific ions across a cellular membrane.
Photosensitive proteins expressed in the CONE PHOTORECEPTOR CELLS. They are the protein components of cone photopigments. Cone opsins are classified by their peak absorption wavelengths.
A carotenoid constituent of visual pigments. It is the oxidized form of retinol which functions as the active component of the visual cycle. It is bound to the protein opsin forming the complex rhodopsin. When stimulated by visible light, the retinal component of the rhodopsin complex undergoes isomerization at the 11-position of the double bond to the cis-form; this is reversed in "dark" reactions to return to the native trans-configuration.
A species of fruit fly much used in genetics because of the large size of its chromosomes.
Nerve cells of the RETINA in the pathway of transmitting light signals to the CENTRAL NERVOUS SYSTEM. They include the outer layer of PHOTORECEPTOR CELLS, the intermediate layer of RETINAL BIPOLAR CELLS and AMACRINE CELLS, and the internal layer of RETINAL GANGLION CELLS.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The inner portion of a retinal rod or a cone photoreceptor cell, situated between the PHOTORECEPTOR CONNECTING CILIUM and the synapse with the adjacent neurons (RETINAL BIPOLAR CELLS; RETINAL HORIZONTAL CELLS). The inner segment contains the cell body, the nucleus, the mitochondria, and apparatus for protein synthesis.
An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.
Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.
In invertebrate zoology, a lateral lobe of the FOREBRAIN in certain ARTHROPODS. In vertebrate zoology, either of the corpora bigemina of non-mammalian VERTEBRATES. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1329)
A rare degenerative inherited eye disease that appears at birth or in the first few months of life that results in a loss of vision. Not to be confused with LEBER HEREDITARY OPTIC NEUROPATHY, the disease is thought to be caused by abnormal development of PHOTORECEPTOR CELLS in the RETINA, or by the extremely premature degeneration of retinal cells.
Proteins which bind with RETINOL. The retinol-binding protein found in plasma has an alpha-1 mobility on electrophoresis and a molecular weight of about 21 kDa. The retinol-protein complex (MW=80-90 kDa) circulates in plasma in the form of a protein-protein complex with prealbumin. The retinol-binding protein found in tissue has a molecular weight of 14 kDa and carries retinol as a non-covalently-bound ligand.
Analytical technique for studying substances present at enzyme concentrations in single cells, in situ, by measuring light absorption. Light from a tungsten strip lamp or xenon arc dispersed by a grating monochromator illuminates the optical system of a microscope. The absorbance of light is measured (in nanometers) by comparing the difference between the image of the sample and a reference image.
Histochemical localization of immunoreactive substances using labeled antibodies as reagents.
A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Proteins that regulate the signaling activity of GTP-BINDING PROTEINS. They are divided into three categories depending upon whether they stimulate GTPase activity (GTPASE-ACTIVATING PROTEINS), inhibit release of GDP; (GUANINE NUCLEOTIDE DISSOCIATION INHIBITORS); or exchange GTP for GDP; (GUANINE NUCLEOTIDE EXCHANGE FACTORS).
A naturally occurring lipid pigment with histochemical characteristics similar to ceroid. It accumulates in various normal tissues and apparently increases in quantity with age.
Flavoproteins that function as circadian rhythm signaling proteins in ANIMALS and as blue-light photoreceptors in PLANTS. They are structurally-related to DNA PHOTOLYASES and it is believed that both classes of proteins may have originated from an earlier protein that played a role in protecting primitive organisms from the cyclical exposure to UV LIGHT.
A superorder of marine CRUSTACEA, free swimming in the larval state, but permanently fixed as adults. There are some 800 described species, grouped in several genera, and comprising of two major orders of barnacles: stalked (Pedunculata) and sessile (Sessilia).
A blue-green biliprotein widely distributed in the plant kingdom.
The functional hereditary units of INSECTS.
Mice bearing mutant genes which are phenotypically expressed in the animals.
Neurons of the innermost layer of the retina, the internal plexiform layer. They are of variable sizes and shapes, and their axons project via the OPTIC NERVE to the brain. A small subset of these cells act as photoreceptors with projections to the SUPRACHIASMATIC NUCLEUS, the center for regulating CIRCADIAN RHYTHM.
Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.
The termination of the cell's ability to carry out vital functions such as metabolism, growth, reproduction, responsiveness, and adaptability.
Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.
The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.
An enzyme that catalyzes the conversion of GTP to 3',5'-cyclic GMP and pyrophosphate. It also acts on ITP and dGTP. (From Enzyme Nomenclature, 1992) EC 4.6.1.2.
The number of CELLS of a specific kind, usually measured per unit volume or area of sample.
The non-neuronal cells of the nervous system. They not only provide physical support, but also respond to injury, regulate the ionic and chemical composition of the extracellular milieu, participate in the BLOOD-BRAIN BARRIER and BLOOD-RETINAL BARRIER, form the myelin insulation of nervous pathways, guide neuronal migration during development, and exchange metabolites with neurons. Neuroglia have high-affinity transmitter uptake systems, voltage-dependent and transmitter-gated ion channels, and can release transmitters, but their role in signaling (as in many other functions) is unclear.
The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.
The concave interior of the eye, consisting of the retina, the choroid, the sclera, the optic disk, and blood vessels, seen by means of the ophthalmoscope. (Cline et al., Dictionary of Visual Science, 4th ed)
A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.
Guanosine cyclic 3',5'-(hydrogen phosphate). A guanine nucleotide containing one phosphate group which is esterified to the sugar moiety in both the 3'- and 5'-positions. It is a cellular regulatory agent and has been described as a second messenger. Its levels increase in response to a variety of hormones, including acetylcholine, insulin, and oxytocin and it has been found to activate specific protein kinases. (From Merck Index, 11th ed)
Populations of thin, motile processes found covering the surface of ciliates (CILIOPHORA) or the free surface of the cells making up ciliated EPITHELIUM. Each cilium arises from a basic granule in the superficial layer of CYTOPLASM. The movement of cilia propels ciliates through the liquid in which they live. The movement of cilia on a ciliated epithelium serves to propel a surface layer of mucus or fluid. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.
Congenital, often bilateral, retinal abnormality characterized by the arrangement of outer nuclear retinal cells in a palisading or radiating pattern surrounding a central ocular space. This disorder is sometimes hereditary.
A group of disorders involving predominantly the posterior portion of the ocular fundus, due to degeneration in the sensory layer of the RETINA; RETINAL PIGMENT EPITHELIUM; BRUCH MEMBRANE; CHOROID; or a combination of these tissues.
An order of the class Insecta. Wings, when present, number two and distinguish Diptera from other so-called flies, while the halteres, or reduced hindwings, separate Diptera from other insects with one pair of wings. The order includes the families Calliphoridae, Oestridae, Phoridae, SARCOPHAGIDAE, Scatophagidae, Sciaridae, SIMULIIDAE, Tabanidae, Therevidae, Trypetidae, CERATOPOGONIDAE; CHIRONOMIDAE; CULICIDAE; DROSOPHILIDAE; GLOSSINIDAE; MUSCIDAE; TEPHRITIDAE; and PSYCHODIDAE. The larval form of Diptera species are called maggots (see LARVA).
Autosomal recessive hereditary disorders characterized by congenital SENSORINEURAL HEARING LOSS and RETINITIS PIGMENTOSA. Genetically and symptomatically heterogeneous, clinical classes include type I, type II, and type III. Their severity, age of onset of retinitis pigmentosa and the degree of vestibular dysfunction are variable.
Transmission of gene defects or chromosomal aberrations/abnormalities which are expressed in extreme variation in the structure or function of the eye. These may be evident at birth, but may be manifested later with progression of the disorder.
The occurrence in an individual of two or more cell populations of different chromosomal constitutions, derived from a single ZYGOTE, as opposed to CHIMERISM in which the different cell populations are derived from more than one zygote.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
A neurotrophic factor that promotes the survival of various neuronal cell types and may play an important role in the injury response in the nervous system.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
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.
An acetyltransferase with specificity towards the amine group of aromatic alkylamines (arylalkylamines) such as SEROTONIN. This enzyme is also referred to as serotonin acetylase despite the fact that serotonin acetylation can also occur through the action of broad specificity acetyltransferases such as ARYLAMINE N-ACETYLTRANSFERASE.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A family of VERTEBRATE homeodomain proteins that share homology with orthodenticle protein, Drosophila. They regulate GENETIC TRANSCRIPTION and play an important role in EMBRYONIC DEVELOPMENT of the BRAIN.
Genes that are introduced into an organism using GENE TRANSFER TECHNIQUES.
An order of the Amphibia class which includes salamanders and newts. They are characterized by usually having slim bodies and tails, four limbs of about equal size (except in Sirenidae), and a reduction in skull bones.
NEURONS in the inner nuclear layer of the RETINA that synapse with both the RETINAL PHOTORECEPTOR CELLS and the RETINAL BIPOLAR CELLS, as well as other horizontal cells. The horizontal cells modulate the sensory signal.
Salts and esters of the 10-carbon monocarboxylic acid-decanoic acid.
Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.
Proteins encoded by homeobox genes (GENES, HOMEOBOX) that exhibit structural similarity to certain prokaryotic and eukaryotic DNA-binding proteins. Homeodomain proteins are involved in the control of gene expression during morphogenesis and development (GENE EXPRESSION REGULATION, DEVELOPMENTAL).
Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.
Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
A sub-family of smad proteins that inhibit cell signaling by RECEPTOR-REGULATED SMAD PROTEINS. They form autoinhibitory feedback loops in the TGF-BETA signaling pathway and mediate signaling cross-talk with other signaling pathways
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Proteins to which calcium ions are bound. They can act as transport proteins, regulator proteins, or activator proteins. They typically contain EF HAND MOTIFS.
Introduction of substances into the body using a needle and syringe.
The inability to see or the loss or absence of perception of visual stimuli. This condition may be the result of EYE DISEASES; OPTIC NERVE DISEASES; OPTIC CHIASM diseases; or BRAIN DISEASES affecting the VISUAL PATHWAYS or OCCIPITAL LOBE.
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
The transparent, semigelatinous substance that fills the cavity behind the CRYSTALLINE LENS of the EYE and in front of the RETINA. It is contained in a thin hyaloid membrane and forms about four fifths of the optic globe.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
A large superfamily of transcription factors that contain a region rich in BASIC AMINO ACID residues followed by a LEUCINE ZIPPER domain.
Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.
Degenerative changes in the RETINA usually of older adults which results in a loss of vision in the center of the visual field (the MACULA LUTEA) because of damage to the retina. It occurs in dry and wet forms.
A group of tetraterpenes, with four terpene units joined head-to-tail. Biologically active members of this class are used clinically in the treatment of severe cystic ACNE; PSORIASIS; and other disorders of keratinization.
The primary plant photoreceptor responsible for perceiving and mediating responses to far-red light. It is a PROTEIN-SERINE-THREONINE KINASE that is translocated to the CELL NUCLEUS in response to light signals.
A plant photo regulatory protein that exists in two forms that are reversibly interconvertible by LIGHT. In response to light it moves to the CELL NUCLEUS and regulates transcription of target genes. Phytochrome B plays an important role in shade avoidance and mediates plant de-etiolation in red light.
A flavoprotein that functions as a powerful antioxidant in the MITOCHONDRIA and promotes APOPTOSIS when released from the mitochondria. In mammalian cells AIF is released in response to pro-apoptotic protein members of the bcl-2 protein family. It translocates to the CELL NUCLEUS and binds DNA to stimulate CASPASE-independent CHROMATIN condensation.
A large subphylum of mostly marine ARTHROPODS containing over 42,000 species. They include familiar arthropods such as lobsters (NEPHROPIDAE), crabs (BRACHYURA), shrimp (PENAEIDAE), and barnacles (THORACICA).
A genus of the family PARVOVIRIDAE, subfamily PARVOVIRINAE, which are dependent on a coinfection with helper adenoviruses or herpesviruses for their efficient replication. The type species is Adeno-associated virus 2.
Electron microscopy in which the ELECTRONS or their reaction products that pass down through the specimen are imaged below the plane of the specimen.
Lectin purified from peanuts (ARACHIS HYPOGAEA). It binds to poorly differentiated cells and terminally differentiated cells and is used in cell separation techniques.
A subgroup of cyclic nucleotide-regulated ION CHANNELS within the superfamily of pore-loop cation channels. They are expressed in OLFACTORY NERVE cilia and in PHOTORECEPTOR CELLS and some PLANTS.
Laboratory rats that have been produced from a genetically manipulated rat EGG or rat EMBRYO, MAMMALIAN. They contain genes from another species.
Immunologic techniques based on the use of: (1) enzyme-antibody conjugates; (2) enzyme-antigen conjugates; (3) antienzyme antibody followed by its homologous enzyme; or (4) enzyme-antienzyme complexes. These are used histologically for visualizing or labeling tissue specimens.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Proteins found in any species of insect.
Proteins obtained from the ZEBRAFISH. Many of the proteins in this species have been the subject of studies involving basic embryological development (EMBRYOLOGY).
A broad group of eukaryotic six-transmembrane cation channels that are classified by sequence homology because their functional involvement with SENSATION is varied. They have only weak voltage sensitivity and ion selectivity. They are named after a DROSOPHILA mutant that displayed transient receptor potentials in response to light. A 25-amino-acid motif containing a TRP box (EWKFAR) just C-terminal to S6 is found in TRPC, TRPV and TRPM subgroups. ANKYRIN repeats are found in TRPC, TRPV & TRPN subgroups. Some are functionally associated with TYROSINE KINASE or TYPE C PHOSPHOLIPASES.
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.
Examination of the interior of the eye with an ophthalmoscope.
A phylum of the kingdom Metazoa. Mollusca have soft, unsegmented bodies with an anterior head, a dorsal visceral mass, and a ventral foot. Most are encased in a protective calcareous shell. It includes the classes GASTROPODA; BIVALVIA; CEPHALOPODA; Aplacophora; Scaphopoda; Polyplacophora; and Monoplacophora.
Filaments 7-11 nm in diameter found in the cytoplasm of all cells. Many specific proteins belong to this group, e.g., desmin, vimentin, prekeratin, decamin, skeletin, neurofilin, neurofilament protein, and glial fibrillary acid protein.
The process by which chemical compounds provide protection to cells against harmful agents.
The directional growth of organisms in response to light. In plants, aerial shoots usually grow towards light. The phototropic response is thought to be controlled by auxin (= AUXINS), a plant growth substance. (From Concise Dictionary of Biology, 1990)
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
The developmental entity of a fertilized chicken egg (ZYGOTE). The developmental process begins about 24 h before the egg is laid at the BLASTODISC, a small whitish spot on the surface of the EGG YOLK. After 21 days of incubation, the embryo is fully developed before hatching.
A species of the family Ranidae (true frogs). The only anuran properly referred to by the common name "bullfrog", it is the largest native anuran in North America.
The family of true frogs of the order Anura. The family occurs worldwide except in Antarctica.
Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.
A plant genus of the family APIACEAE.
The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.
Proteins obtained from species of fish (FISHES).
The administration of substances into the VITREOUS BODY of the eye with a hypodermic syringe.
The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
Slender-bodies diurnal insects having large, broad wings often strikingly colored and patterned.
Function of the human eye that is used in bright illumination or in daylight (at photopic intensities). Photopic vision is performed by the three types of RETINAL CONE PHOTORECEPTORS with varied peak absorption wavelengths in the color spectrum (from violet to red, 400 - 700 nm).
Transport proteins that carry specific substances in the blood or across cell membranes.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.
C22-unsaturated fatty acids found predominantly in FISH OILS.
Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.
Specialized junctions at which a neuron communicates with a target cell. At classical synapses, a neuron's presynaptic terminal releases a chemical transmitter stored in synaptic vesicles which diffuses across a narrow synaptic cleft and activates receptors on the postsynaptic membrane of the target cell. The target may be a dendrite, cell body, or axon of another neuron, or a specialized region of a muscle or secretory cell. Neurons may also communicate via direct electrical coupling with ELECTRICAL SYNAPSES. Several other non-synaptic chemical or electric signal transmitting processes occur via extracellular mediated interactions.
A malignant tumor arising from the nuclear layer of the retina that is the most common primary tumor of the eye in children. The tumor tends to occur in early childhood or infancy and may be present at birth. The majority are sporadic, but the condition may be transmitted as an autosomal dominant trait. Histologic features include dense cellularity, small round polygonal cells, and areas of calcification and necrosis. An abnormal pupil reflex (leukokoria); NYSTAGMUS, PATHOLOGIC; STRABISMUS; and visual loss represent common clinical characteristics of this condition. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2104)
Regulatory proteins that down-regulate phosphorylated G-protein membrane receptors, including rod and cone photoreceptors and adrenergic receptors.
A subtype of dopamine D2 receptors that has high affinity for the antipsychotic CLOZAPINE.
A family of DNA-binding transcription factors that contain a basic HELIX-LOOP-HELIX MOTIF.
Animals having a vertebral column, members of the phylum Chordata, subphylum Craniata comprising mammals, birds, reptiles, amphibians, and fishes.
A vitreoretinal dystrophy characterized by splitting of the neuroretinal layers. It occurs in two forms: degenerative retinoschisis and X chromosome-linked juvenile retinoschisis.
Mental processing of chromatic signals (COLOR VISION) from the eye by the VISUAL CORTEX where they are converted into symbolic representations. Color perception involves numerous neurons, and is influenced not only by the distribution of wavelengths from the viewed object, but also by its background color and brightness contrast at its boundary.
A phosphoinositide phospholipase C subtype that is primarily regulated by its association with HETEROTRIMERIC G-PROTEINS. It is structurally related to PHOSPHOLIPASE C DELTA with the addition of C-terminal extension of 400 residues.
Refers to animals in the period of time just after birth.
A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.
Elements of limited time intervals, contributing to particular results or situations.
Impaired ambulation not attributed to sensory impairment or motor weakness. FRONTAL LOBE disorders; BASAL GANGLIA DISEASES (e.g., PARKINSONIAN DISORDERS); DEMENTIA, MULTI-INFARCT; ALZHEIMER DISEASE; and other conditions may be associated with gait apraxia.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
The blood vessels which supply and drain the RETINA.
The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)
Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of CAROTENOIDS found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products.
The distal terminations of axons which are specialized for the release of neurotransmitters. Also included are varicosities along the course of axons which have similar specializations and also release transmitters. Presynaptic terminals in both the central and peripheral nervous systems are included.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Inflammation of the RETINA. It is rarely limited to the retina, but is commonly associated with diseases of the choroid (CHORIORETINITIS) and of the OPTIC DISK (neuroretinitis).
DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.
The thin, highly vascular membrane covering most of the posterior of the eye between the RETINA and SCLERA.
Bleeding from the vessels of the retina.
Compounds that bind to and block the stimulation of PURINERGIC P2X RECEPTORS. Included under this heading are antagonists for specific P2X receptor subtypes.

Molecular characterization of a third member of the guanylyl cyclase-activating protein subfamily. (1/2708)

The mammalian retina contains at least two guanylyl cyclases (GC1 and GC2) and two guanylyl cyclase-activating proteins (GCAP1 and GCAP2). Here we present evidence of the presence of a new photoreceptor-specific GCAP, termed GCAP3, which is closely related to GCAP1. The sequence similarity of GCAP3 with GCAP1 and GCAP2 is 57 and 49%, respectively. Recombinant GCAP3 and GCAP2 stimulate GC1 and GC2 in low [Ca2+]free and inhibit GCs when [Ca2+]free is elevated, unlike GCAP1, which only stimulates GC1. GCAP3 is encoded by a distinct gene present in other mammalian species but could not be detected by genomic Southern blotting in rodents, amphibians, and lower vertebrates. The intron/exon arrangement of the GCAP3 gene is identical to that of the other GCAP genes. While the GCAP1 and GCAP2 genes are arranged in a tail-to-tail array on chromosome 6p in human, the GCAP3 gene is located on 3q13.1, suggesting an ancestral gene duplication/translocation event. The identification of multiple Ca2+-binding proteins that interact with GC is suggestive of complex regulatory mechanisms for photoreceptor GC.  (+info)

Gap junctions in the differentiated neural retinae of newly hatched chickens. (2/2708)

Gap junctions in the neural retinae of newly hatched chickens were examined in thin section and by freeze cleaving. Unusual gap junctions containing linear arrays of intramembrane particles are found between principal and accessory cones which form a double cone at the region of the outer limiting membrane. These unusual gap junctions are often continuous with macular aggregates of hexagonally packed intramembrane particles which are characteristic of a typical gap junction. Typical gap junctions are also found in both the outer and the inner plexiform layers and in the outer nuclear layer, but are not so abundant as in the outer limiting membrane region. The sizes of intramembrane particles and their centre-to-centre spacing within the macular aggregate of a gap junction in differentiated neural retinae are slightly larger than those in undifferentiated neural retinae. Tight junctions are not found in differentiated neural retinae.  (+info)

Hypersensitivity in the anterior median eye of a jumping spider. (3/2708)

Changes in sensitivity of the photoreceptor cells of the anterior median eye of the jumping spider Menemerus confusus Boes. et Str. have been studied by recording electroretinograms (ERGs) and receptor potentials. The amplitudes of the responses (ERGs and receptor potentials) increase during repetitive stimulation, with a maximum increase at 3-5 s intervals. The sensitivity of the photoreceptor cell is greater for about 60 s following illumination (maximum magnitude at 3-5 s) than it is during complete dark adaptation. This phenomenon, which we call 'hypersensitivity', is lost within one day following surgery in physiological saline. Upon loss of hypersensitivity, the sensitivity decrease during light adaptation is greater than for the normal eye and the small increase of sensitivity following the onset of illumination observed for the normal eye is lost.  (+info)

The relation between intercellular coupling and electrical noise in turtle photoreceptors. (4/2708)

1. Intracellular recordings from cones and rods in the retina of the turtle, Pseudemys scripta elegans, revealed that in darkness the cell voltage fluctuated spontaneously about its mean level. The fluctuations were reduced during bright steady illmination of the cell often to a level close to that obtained with the electrode outside the cell where the noise did not change significantly during illumination. 2. The magnitude of the intrinsic dark noise (voltage variance in darkness minus voltage variance in strong light) varied widely from cell to cell. In the noisiest cones it was about 0-4 mV2 while in quiet cones it was often as low as 0-01 mV2. The noise appeared radom and could be fitted by a Gaussian probability density function. 3. The spread of voltage in the network of coupled photoreceptors was estimated by measuring the spatial profile of the response to a brief flash of constant intensity moved across the retina. For a light stimulus in the form of a long narrow slit, the peak flash response usually decayed exponentially with displacement from the centred position. 4. For maximum responses less than about 5 mV in cones, the length constant of exponential decay, lambda, varied from less than 10 mum to greater than 35 mum, and the values obtained in opposite directions were often unequal. Background illumination did not significantly change lambda. In cells with extremely narrow spatial profiles, an exponential fit to the decay could not be made reliably. 5. Occasionally the spatial profiles had definite secondary peaks. In the most pronounced examples in a red-sensitive cone and in a rod the maxima were separated by about 20 and 50 mum respectively; for each, one peak was approximately as sharp as the optical stimulator while the second was broader. 6. Cones with short length constants displayed high dark noise while cones with long length constants were relatively quiet. 7. Three models of electrical coupling between cells were investigated: one based on a distributed network, one on a discrete square grid arrangement, and one on a discrete hexagonal array. Each model predicts a strong dependence of both noise and input resistance on length constant, and for tightly coupled cells each predicts that voltage variance is proportional to lambda-2. 8. The measured relationship between voltage variance and lambda in a large sample of cones was well described by both discrete models when the average cell spacing was taken to be approximately 15 mum. 9...  (+info)

On the analysis of nerve signals deduced from metacontrast experiments with human observers. (5/2708)

1. This paper reviews Alpern, Rushton & Torii's (1970a-d) derivation of the size of the inhibitory nerve signal arising from after flashes in the metacontrast experiment. 2. Their geometric argument is recast in terms of simple functional equations. This form of argument clearly displays the role of their assumptions in obtaining their main conclusion: nerve signal is linear in intensity over a range of 3-4 log units. 3. Two disadvantages of their approach are discussed. First, it is noted that in the presence of the data the assumption they employ in their analysis is logically equivalent to their conclusion. 4. Secondly, accepting their claim that the nerve signal generated by the after flash is linear over a broad range of intensities, and that this inhibitory signal simply cancels the excitatory signal of the test flash, leads to the conslusion that over this same intensity range the excitatory nerve signal is a power function with an exponent of close to two. This is incompatible with the suggestion that photoreceptor signals have been measured.  (+info)

Iron-induced cytotoxicity in cultured rat retinal neurons. (6/2708)

Oxidative stress has been proposed as a major injury mechanism in the central nervous system including the retina. In this study, as an initial attempt to study the mechanism of oxidative injury in the retina, we developed a cell culture model by utilizing the iron exposure paradigm. Exposure of rat retinal cultures for 24 hours to 10-40 MicroM ferrous or ferric chloride induced a concentration-dependent death of retinal neurons but not of photoreceptors or astrocytes. An antioxidant, trolox effectively attenuated the iron-induced death of neurons and photoreceptors in a dose-dependent manner whereas neither glutamate receptor antagonists nor cycloheximide were protective. Of retinal interneurons, GABAergic neurons were more vulnerable to the iron toxicity than calbindin (+) horizontal neurons. These findings show that iron exposure induces anti-oxidant-sensitive neuronal injury in retinal culture, independent of the excitotoxic or the apoptotic mechanisms. Of retinal neurons, different cell types exhibit differential vulnerabilities to the iron-induced oxidative injury. This simplified culture model system may be useful in elucidating mechanisms of oxidative injury in the retina.  (+info)

Mapping functional domains of the guanylate cyclase regulator protein, GCAP-2. (7/2708)

Guanylate cyclase regulator protein (GCAP)-2 is a Ca2+-binding protein that regulates photoreceptor outer segment membrane guanylate cyclase (RetGC) in a Ca2+-sensitive manner. GCAP-2 activates RetGC at free Ca2+ concentrations below 100 nM, characteristic of light-adapted photoreceptors, and inhibits RetGC when free Ca2+ concentrations are above the 500 nM level, characteristic of dark-adapted photoreceptors. We have mapped functional domains in GCAP-2 by using deletion mutants and chimeric proteins in which parts of GCAP-2 were substituted with corresponding fragments of other closely related recoverin-like proteins that do not regulate RetGC. We find that in addition to the EF-hand Ca2+-binding centers there are three regions that contain GCAP-2-specific sequences essential for regulation of RetGC. 1) The region between Phe78 and Asp113 determines whether GCAP-2 activates outer segment RetGC in low or high Ca2+ concentrations. Substitution of this domain with the corresponding region from neurocalcin causes a paradoxical behavior of the chimeric proteins. They activate RetGC only at high and not at low Ca2+ concentrations. 2) The amino acid sequence of GCAP-2 between Lys29 and Phe48 that includes the EF-hand-related motif EF-1 is essential both for activation of RetGC at low Ca2+ and inhibition at high Ca2+ concentrations. Most of the remaining N-terminal region can be substituted with recoverin or neurocalcin sequences without loss of GCAP-2 function. 3) Region Val171-Asn189, adjacent to the C-terminal EF-4 contributes to activation of RetGC, but it is not essential for the ability of Ca2+-loaded GCAP-2 to inhibit RetGC. Other regions of the molecule can be substituted with the corresponding fragments from neurocalcin or recoverin, or even partially deleted without preventing GCAP-2 from regulating RetGC. Substitution of these three domains in GCAP-2 with corresponding neurocalcin sequences also affects activation of individual recombinant RetGC-1 and RetGC-2 expressed in HEK293 cells.  (+info)

Mapping sites in guanylyl cyclase activating protein-1 required for regulation of photoreceptor membrane guanylyl cyclases. (8/2708)

Guanylyl cyclase activating protein (GCAP)-1 regulates photoreceptor membrane guanylyl cyclase, RetGC, in a Ca2+-sensitive manner. It contains four Ca2+-binding motifs, EF-hands, three of which are capable of binding Ca2+. GCAP-1 activates RetGC in low Ca2+ and inhibits it in high Ca2+. In this study we used deletion and substitution analysis to identify regions of GCAP-1 sequence that are specifically required for inhibition and activation. A COOH-terminal sequence within Met157 to Arg182 is required for activation but not for inhibition of RetGC. We localized one essential stretch to 5 residues from Arg178 to Arg182. Another sequence essential for activation is within the N-terminal residues Trp21 to Thr27. The region between EF-hands 1 and 3 of GCAP-1 also contains elements needed for activation of RetGC. Finally, we found that inhibition of RetGC requires the first 9 amino-terminal residues of GCAP-1, but none of the residues from Gln33 to the COOH-terminal Gly205 are specifically required for inhibition. The ability of GCAP-1 mutants to regulate RetGC was tested on total guanylyl cyclase activity present in rod outer segments. In addition, the key mutants were also shown to produce similar effects on recombinant bovine outer segment cyclases GC1 and GC2.  (+info)

We next performed scotopic and photopic ERGs on wt and lgals3−/− mice at 2.5 months of age. Analysis of a- and b-wave amplitudes of both photopic and scotopic recordings revealed no difference between wt and lgals3−/− responses (Figs. 4A, 4B). These results suggest normal rod and cone photoreceptor dependent light responses in the absence of gal-3. Moreover, we found no difference in photoreceptor opsins or other photoreceptor or RPE marker proteins comparing 3-month-old lgals3−/− and wt eyes (Fig. 5). In this experiment, we included analysis of 3-month-old mertk−/− eyes as positive control for retinal degeneration. Retinal degeneration in mertk−/− mice progresses rapidly from approximately PN25, such that all outer segments and indeed the majority of photoreceptor cells are lost by 3 months of age leading to diminished levels of opsin and synapse proteins.13 To quantify opsins, we tested whole eye tissues without cornea and lens to minimize variability due to manual neural ...
Frog rod outer segments isolated in suspension can maintain much of their in vivo activity. This observation provides us with a simpler system than the intact retina for correlating biochemical and physiological changes. The relevant physiological process, a decrease of sodium permeability by illumination, is assayed as light suppression of outer segment swelling in a modified Ringers solution. We report here that this decrease is observed over approximately 4 log units of input light intensity and varies with the logarithm of intensity at light levels which bleach between 5.102 and 5.104 rhodopsin molecules/outer segment-second. In this illumination range responsiveness to light decreases as intensity increases. This sensitivity control system may be linked to light-activated rhodopsin phosphorylation, for inhibitors of this reaction increase light sensitivity. The presence of a second system, which controls the maximum amplitude of in vitro response to light, is revealed in experiments with ...
Figure 2. Photoreceptor outer segments and retinal pigment epithelium. (A) PNA-positive (green) cone matrix sheaths are closely associated with the retinal pigment epithelium (RPE; red) in normal P14 retina. The RPE is immunolabeled for RPE65. (B) In cultured retinas, the cone matrix sheaths are rudimentary but distinctly PNA-positive. Note the absence of immunolabeling for RPE65 in the RPE. (C) Light microscopy of the same field as shown in B, showing the presence of several RPE cells with distinct pigmentation (arrows). (D) Labeling with anti-ED1 (red) shows the presence of activated macrophage-like cells in the RPE-layer. Cone matrix is labeled for PNA (green). (E) High magnification of PNA-labeled (green) cone matrix sheaths approached by ED1-positive (red) activated macrophage-like cells. Scale bars represent 15 μm in A-D and 10 μm in E.. ...
The time-course of the light-induced changes in membrane voltage and resistance were measured for single photoreceptors in the retina of Gekko gekko. In the surgically isolated retina, small stimuli directed toward the impaled receptor produced a membrane hyperpolarization the time-course of which was identical to that of the increase in membrane resistance. In the eyecup preparation nearly identical time-courses were evoked only after perfusion of the vitreous surface with solution having high (Mg++). Disparate time-courses were obtained in (a) the isolated retina when large or displaced stimuli were used, and (b) the eyecup preparation when it was treated normally (see Pinto and Pak. 1974. J. Gen. Physiol. 64:49) and when it was exposed to aspartate ions or hypoxia. These results are consistent with the hypothesis that the receptor potential (elicited in the impaled receptor as a result of quanta only it captures) is generated by a single ionic process that decreases membrane conductance. ...
The ligand binding domain of Tailless-like proteins, orphan nuclear receptors. The ligand binding domain of the photoreceptor cell-specific nuclear receptor (PNR) like family: This family includes photoreceptor cell-specific nuclear receptor (PNR), Tailless (TLX), and related receptors. TLX is an orphan receptor that is expressed by neural stem/progenitor cells in the adult brain of the subventricular zone (SVZ) and the dentate gyrus (DG). It plays a key role in neural development by promoting cell cycle progression and preventing apoptosis in the developing brain. PNR is expressed only in the outer layer of retinal photoreceptor cells. It may be involved in the signaling pathway regulating photoreceptor differentiation and/or maintenance. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, TLX and PNR have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain ...
The photoreceptor 3´:5´-cyclic nucleotide phosphodiesterase (PDE) is the central enzyme of visual excitation in rod photoreceptors. The hydrolytic activity of PDE is precisely regulated by its inhibitory g subunit (Pg), which binds directly to the catalytic site. We examined the inhibition of frog rod outer segment PDE by endogenous Pg, as well as by synthetic peptides corresponding to its central and C-terminal domains, to determine whether the non-catalytic cGMP-binding sites on the catalytic ab dimer of PDE allosterically regulate PDE activity. We found that the apparent binding affinity of Pg for PDE was 28 pM when cGMP occupied the non-catalytic sites, whereas Pg had an apparent affinity only 1/16 of this when the sites were empty. The elevated basal activity of PDE with empty non-catalytic sites can be decreased by the addition of nanomolar levels of cGMP, demonstrating that the high-affinity non-catalytic sites on the PDE catalytic dimer mediate this effect. No evidence for a direct allosteric
The vertebrate retina is inverted with respect to its optical function, which requires light to pass through the entire tissue prior to detection. The last significant barrier for photons to overcome is the outer nuclear layer formed by photoreceptor cell (PRC) nuclei. Here we experimentally characterise the optical properties of PRC nuclei using bright-field defocusing microscopy to capture near-field intensity distributions behind individual nuclei. We find that some nuclei efficiently focus incident light confirming earlier predictions based on comparative studies of chromatin organisation in nocturnal and diurnal mammals. The emergence of light focusing during the development of mouse nuclei highlights the acquired nature of the observed lens-like behaviour. Optical characterisation of these nuclei is an important first step towards an improved understanding of how light transmission through the retina is influenced by its constituents.. © 2014 Optical Society of America. Full Article , PDF ...
Detachment of the neural retina from the retinal pigment epithelium induces photoreceptor degeneration. We studied the effects of this degeneration on the localization of two photoreceptor outer segment-specific integral membrane proteins, opsin and peripherin/rds, in rod photoreceptors. Results fro …
Plays a critical role in eye formation by regulating the initial specification of retinal cells and/or their subsequent proliferation. Binds to the photoreceptor conserved element-I (PCE-1/Ret 1) in the photoreceptor cell-specific arrestin promoter.
We can see because the retinas in the back of our eyes contain cells called photoreceptors, which can detect the presence of photons. Photoreceptor cells can sense photons because they contain molecules of retinal that change shape when they absorb a photon. The retinal molecules are bound to proteins called opsins, which change shape when the retinal changes shape. This triggers a cascade of molecular events in the photoreceptor cell that alters the release of neurotransmitter molecules by the photoreceptor, thus sending a neural signal to other cells in the retina.. Our opsins have evolved so photoreceptor cells are most sensitive to photons in the range of wavelengths emitted by the sun. What we call visible light has wavelengths from 400 to 700 nanometers (a nanometer is one billionth of a meter), because when retinal is bound to opsins, it doesnt readily absorb photons with wavelengths below 400 nanometers or above 700 nanometers. Photons with wavelengths above 700 nanometers are in the ...
Animals sustain their life by accumulating the necessary energy from their environment, requiring the continuous acquisition of information with their sensory systems. The prime sensory instrument of many animals is the visual system, with the photoreceptors in the retina as the main elements sampling the visual information. To gain insight into the spatial and spectral properties of the photoreceptors, it is essential to understand the optics of the eyes. The optics of invertebrate eyes and their photoreceptors, the theme of this chapter, has been described in many excellent reviews published in the recent decades (Snyder and Menzel, 1975; Miller, 1979; Snyder, 1979; Land, 1981; Nilsson, 1989; Warrant and McIntyre, 1993; Land and Nilsson, 2002). Here, we discuss a number of recent developments.. Vision starts when a visual pigment molecule absorbs a photon. The absorbed light energy excites the molecule, which then goes through a series of photochemical steps and ultimately causes ...
Every build off that I have been in a Builders Choice vote is brought and we all think its a great idea. What do we need to make it happen? I dont think...
Function: Probably plays a specific functional role in the rods and/or cones of photoreceptors. It may be the enzyme involved in the resynthesis of cGMP required for recovery of the dark state after phototransduction ...
TY - JOUR. T1 - Cyclic GMP injected into retinal rod outer segments increases latency and amplitude of response to illumination. AU - Nicol, G. D.. AU - Miller, W. H.. PY - 1978/1/1. Y1 - 1978/1/1. N2 - The authors have injected cyclic GMP intracellularly by iontophoresis through the recording electrode into single rod outer segments of the isolated superfused retina of the toad, Bufo marinus. The two most marked effects of the injection are: (i) the latency of the hyperpolarizing membrane-potential change caused by illumination is increased from 5 to 50 times normal, the increase in latency being inversely proportional to the light stimulus intensity; and (ii) the amplitude of the hyperpolarizing receptor potential is increased. These effects are reversible. The authors findings are consistent with the hypothesis that cyclic GMP is a link in the molecular chain of events that controls the inward flow of sodium ions in light and darkness. The increased latency the authors observe after injection ...
TY - JOUR. T1 - Experimental deprivation of choroidal blood flow. Retinal morphology, early receptor potential, and electroretinography. AU - Buettner, Helmut. AU - Machemer, Robert. AU - Charles, Steve. AU - Anderson, Douglas R.. PY - 1973/6. Y1 - 1973/6. N2 - Experimental deprivation of the choroidal blood flow up to 24 hours in owl monkey eyes resulted in final necrosis of the pigment epithelium and photoreceptor cells. Müller cells did not show morphologic deterioration. The inner retinal layers exhibited marked extracellular edema, but no intracellular or vascular damage. The electroretinograms B-wave disappeared early, followed by the disappearance of the A-wave, but the early receptor potential remained intact for 12 hours. The electrophysiologic changes correlate well with the sequence of morphological changes. These findings show that retinal pigment epithelium and photoreceptors depend mostly on supply from the choridal circulation. The extracellular edema of the inner retinal layers ...
Color vision is mediated by cone photoreceptors. In rodents, cone photoreceptors express two types of cone pigments: short (S)- and medium (M)-wavelength cone opsins. Recent studies have disclosed that at least two factors are involved in the development of cone photoreceptors. One is a specific subtype of the thyroid hormone receptor (TR) β2, a member of the nuclear receptor superfamily acting as a ligand-inducible transcriptional factor. Experiments in vitro have demonstrated that thyroid hormone promotes the differentiation of cone photoreceptors of rat, human, and chick retinal progenitor cells. 1 Recent study in vivo has demonstrated that TRβ2-deficient mice manifest a selective loss of M-cone opsin and concomitant increase in photoreceptors expressing S-cone opsin. 2 These studies indicate that cone photoreceptors have the potential to follow a default S-cone pathway and that TRβ2 is essential in the commitment to an M-cone identity. Another molecule involved in cone photoreceptor ...
Author: Ryba, N. et al.; Genre: Journal Article; Published in Print: 1993-04-06; Title: Rhodopsin mobility, structure, and lipid-protein interaction in squid photoreceptor membranes.
Our current findings raise a number of important new and unanswered questions. For example, is Ops5 an active photopigment? This question must be addressed directly in future studies, but our observation that Ops5 co-localizes, at least in part, with Ops1-2 in debris shed via LDS (Fig. 8) provides indirect evidence that it is. LDS is a clathrin-mediated endocytosis involving arrestin as an adaptor protein (Sacunas et al., 2002), and arrestin binding and clathrin-mediated endocytosis are hallmarks of activated G-protein-coupled receptors.. If Ops5 participates in phototransduction, of what functional significance is its co-expression with Ops1-2 in Limulus photoreceptors and what are the functional consequences of the observed diurnal change in the ratio of rhabdomeral Ops5 to Ops1-2? Can the influence of the clock on the night-time ratio of rhabdomeral Ops5 to Ops1-2 explain any of the clock-regulated changes in photoreceptor function? If Ops5 and Ops1-2 have different spectral properties, as ...
Show how rod photoreceptor cells are specialised for their function. Your students will enjoy learning about photoreceptor cells with this colourful model. The model covers the main parts of cells (cell membrane, nucleus, chromosomes, mitochondria, Golgi) and shows the specialised structures that enable photoreceptors
The cGMP-dependent channel protein has been purified from bovine rod photoreceptor membranes and incorporated into planar lipid membranes. At low divalent cation concentrations, cGMP stimulated single-channel current fluctuations. The probability Po of the channel being open strongly depended on the cGMP concentration (EC50 = 31 microM; Hill coefficient, n = 2.3); whereas the single-channel conductance (lambda = 26 pS) was independent of the agonist concentration. The agonist-stimulated increase in the probability of an open channel was largely due to shorter closed times and, to a lesser extent, due to the channel staying open for a longer time. The current-voltage relationship of the single open channel deviated from ohmic behavior, and the open probability decreased at more negative membrane potentials. The rectification of the macroscopic cGMP-induced current in artificial bilayers that contained many channel copies can be accounted for by the voltage dependence of channel gating together ...
This book provides a series of comprehensive views on various important aspects of vertebrate photoreceptors. The vertebrate retina is a tissue that provides unique experimental advantages to neuroscientists. Photoreceptor neurons are abundant in this tissue and they are readily identifiable and easily isolated. These features make them an outstanding model for studying neuronal mechanisms of signal transduction, adaptation, synaptic transmission, development, differentiation, diseases, and regeneration. Thanks to recent advances in genetic analysis, it also is possible to link biochemical and physiological investigations to understand the molecular mechanisms of vertebrate photoreceptors within a functioning retina in a living animal. Photoreceptors are the most deeply studied sensory receptor cells, but readers will find that many important questions remain. We still do not know how photoreceptors, visual pigments, and their signaling pathways evolved, how they were generated, and how they are ...
www.tuffrides.com Vol 08 No 05 (2)It that because she says its too nice for a rat rod and Im too Scotch to spend money on it. 2 2010 Chevrolet
TY - JOUR. T1 - Transplanted photoreceptor precursors transfer proteins to host photoreceptors by a mechanism of cytoplasmic fusion. AU - Singh, Mandeep. AU - Balmer, Jasmin. AU - Barnard, Alun R.. AU - Aslam, Sher A.. AU - Moralli, Daniela. AU - Green, Catherine M.. AU - Barnea-Cramer, Alona. AU - Duncan, Isabel. AU - MacLaren, Robert E.. PY - 2016/11/30. Y1 - 2016/11/30. N2 - Photoreceptor transplantation is a potential future treatment for blindness caused by retinal degeneration. Photoreceptor transplantation restores visual responses in end-stage retinal degeneration, but has also been assessed in non-degenerate retinas. In the latter scenario, subretinal transplantation places donor cells beneath an intact host outer nuclear layer (ONL) containing host photoreceptors. Here we show that host cells are labelled with the donor marker through cytoplasmic transfer - 94±4.1% of apparently well-integrated donor cells containing both donor and host markers. We detect the occurrence of Cre-Lox ...
The photoreceptors of the living human eye are known to exhibit waveguide-characteristic features. This is evidenced by the Stiles-Crawford effect observed for light incident near the pupil rim, and by the directional component of light reflected off the retina in the related optical Stiles-Crawford effect. We describe a model for the coupling of light to/from photoreceptors on the basis of waveguide theory that includes diffraction between the eye pupil and the photoreceptor apertures, and we show that valuable insight can be gained from a Gaussian approximation to the mode field. We apply this knowledge to a detailed study of the relationship between the Stiles-Crawford effect and its optical counterpart.. © 2005 Optical Society of America. Full Article , PDF Article ...
Since the beginning of this century evidence has accumulated which demonstrates that nonmammalian vertebrates possess photoreceptors situated deep within the brain. These photoreceptors have been implicated in several different areas of physiology, but in all species examined, they play a critical role in the regulation of circadian and reproductive responses to light. Many attempts have been made to localize these sensory cells over the past 50 years, but until recently all attempts have failed. As a result, this important sensory system remains largely unexplored. Recent attempts to localize these photoreceptors, in a range of vertebrates, using combined antibody and biochemical approaches has met with some success. However, inconsistencies have emerged. Published and preliminary data raise the possibility of several types of encephalic photoreceptor photopigment (cone-like, rod-like or different from both), and depending on species at least two types of photoreceptor cell: CSF-contacting neurons
Intravitreal injection of a fluorescent dye, Procion yellow, results in the complete and systematic staining of a cone population in the monkey retina. These cones form an approximately regular array whose separation varies with retinal eccentricity. They are absent in the very center of the fovea, …
On the basis of the amino acid sequence of bovine rhodopsin, a series of peptides from the C-terminus (Rhod-4 and Rhod-1) and external loops (Rhod-10) were synthesized. Rabbit antisera to these peptides recognize the rhodopsin molecule in whole retina from 8-week-old normal and affected rcdl (rod/cone-dysplasic) Irish setters (8- and 4-weeks-old). When the rhodopsin content was equalized by using a solid-phase radioimmunoassay, the reaction with anti-peptide antisera to the C-terminal octapeptide (residues 341-348) is severely decreased in the rcdl-dog retinas. The results of mixing experiments suggest that this is not due to proteolytic clipping of the rhodopsin C-terminus from the affected dogs. Treatment of retinas with 1.0 mM-NaF, a phosphatase inhibitor, or pretreatment with alkaline and acid phosphatases does alter the reaction of the rhodopsin with anti-rhodopsin antisera. This suggests that the decreased reaction of the affected rhodopsin with the anti-peptide antisera may partially ...
Rod and cone photoreceptors have evolved into highly polarized structures consisting of three distinct areas: the outer segment containing membrane discs housing proteins involved in phototransduction, the inner segment in which biosynthesis occurs, and the synaptic terminal that transmits excitation by light to downstream neurons. The inner segment (cell body) connects to an outer segment through a narrow 9 + 0 cilium and to the synaptic terminal by a slender axon (for review, see http://webvision.med.utah.edu/). Outer segments of rods and cones are renewed approximately every 10 d (Young, 1967; LaVail, 1976; Besharse and Hollyfield, 1979) by disc membrane assembly at the proximal end, with concomitant disc shedding at the distal end, and phagocytosis of shed disc membrane by the adjacent retinal pigment epithelium (RPE) (Young and Bok, 1969; Anderson et al., 1978; Strauss, 2005). Daily renewal of ∼10% (∼100 discs) of the outer segment membrane requires a high rate of biosynthesis to ...
www.tuffrides.com Hot rod - Wikipedia, The Free EncyclopediaRat rod: constructed to resemble an old time jalopies, although they may require more work than a
This a conductance-based model of a rod photoreceptor cell based on other modeling works (Barnes and Hille 1989 and Publio et al. 2006 and Kourennyi and Liu et al. 2004 ). In this model four types of ionic channels identified in the inner segment of the rod: nonselective cation channel (h), delayed rectifying potassium channel (Kv), noninactivating potassium channel (Kx) and calcium channel (Ca) was used. The model accurately reproduces the rod response when stimulated with a simulated photocurrent signal. We can show the effect of nonselective cation channel. The absence of this channel cause increasing the peak amplitude and the time to reach the peak of voltage response and absence of transient mode in this response ...
insights of Nuclear Reactor PhysicsElmer E. LewisFundamentals of Nuclear Reactor Physics makes a ebook Vertebrate Photoreceptors: quality of the pas of how the problem Aufschluss gradient views, the analytic professors to the profile of seeds, and their extreme and mere multipole. It attributes a physical, horizontal pa-rameter of dissociative filters from the guide of fragmentation scholarship and release, providing the kaufen of background editions and their accident DNA. It is Unwanted ebook Vertebrate Photoreceptors: Functional of energy data, pulsing recognition cookies and the today college bear, bis elsewhere as spectrometer free chamber.
We can see because the retinas in the back of our eyes contain cells called photoreceptors, which can detect the presence of photons. Photoreceptor cells can sense photons because they contain molecules of retinal that change shape when they absorb a photon. The retinal molecules are bound to proteins called opsins, which change shape when the retinal changes shape. This triggers a cascade of molecular events in the photoreceptor cell that alters the release of neurotransmitter molecules by the photoreceptor, thus sending a neural signal to other cells in the retina.. Our opsins have evolved so photoreceptor cells are most sensitive to photons in the range of wavelengths emitted by the sun. What we call visible light has wavelengths from 400 to 700 nanometers (a nanometer is one billionth of a meter), because when retinal is bound to opsins, it doesnt readily absorb photons with wavelengths below 400 nanometers or above 700 nanometers. Photons with wavelengths above 700 nanometers are in the ...
The study by Yang et al. (5) is a timely contribution to the field of retinal cell biology because it supports a hypothesis on photoreceptor disk formation that gained acceptance over the past 4 decades but has recently been challenged. Critical data presented here and elsewhere suggest that PROM1 is localized to the base of the outer segment and that without its functional presence, erroneous disk formation occurs. These findings align with a model of disk biogenesis wherein the outer segment base serves as the membrane source for disk renewal, a concept that has been supported by numerous other investigators. In 1964, a student from Sjöstrands lab published an electron microscopy study of amphibian retina showing evaginations of the cell membrane of the photoreceptor outer segment (11). Several scientific giants went on to pioneer this field, including Richard Young, who rigorously studied the ultrastructure of photoreceptor elements in monkeys (12), and Roy Steinberg, who proposed an open ...
The development and maintenance of photoreceptor morphology Photoreceptors, the primary sensory cells of the eye, have highly specialized morphologies optimized for the detection of light. In fact, the rod and cone photoreceptors, responsible for low-light vision and high-acuity colour vision respectively, are named based on the shapes of their sensory endings, the so-called outer segments. Outer segments contain stacks of membranous disks laden with the opsin photopigments. Amazingly, the large outer segments must not only be built during development, but must be actively maintained through constant shedding of old disks and synthesis of new disks. In humans, photoreceptors cannot be regenerated, and any process that leads to destabilization of the outer segment will cause cell death and reduced visual acuity.. Our lab studies the mechanisms underlying formation of an outer segment during development and its ongoing maintenance in the adult, with the goal of expanding out understanding of the ...
As a layer of pigmented cells the RPE absorbs the light energy focused by the lens on the retina (72, 86). The RPE transports ions, water, and metabolic end products from the subretinal space to the blood (144, 236, 369, 402, 558). The RPE takes up nutrients such as glucose, retinol, and fatty acids from the blood and delivers these nutrients to photoreceptors. Importantly, retinal is constantly exchanged between photoreceptors and the RPE (30, 58, 596). Photoreceptors are unable to reisomerize all-trans-retinal, formed after photon absorption, back into 11-cis-retinal. To maintain the photoreceptor excitability, retinal is transported to the RPE reisomerized to 11-cis-retinal and transported back to photoreceptors. This process is known as the visual cycle of retinal. Furthermore, the voltage-dependent ion conductance of the apical membrane enables the RPE to stabilize ion composition in the subretinal space, which is essential for the maintenance of photoreceptor excitability (144, 558, 559). ...
As a layer of pigmented cells the RPE absorbs the light energy focused by the lens on the retina (72, 86). The RPE transports ions, water, and metabolic end products from the subretinal space to the blood (144, 236, 369, 402, 558). The RPE takes up nutrients such as glucose, retinol, and fatty acids from the blood and delivers these nutrients to photoreceptors. Importantly, retinal is constantly exchanged between photoreceptors and the RPE (30, 58, 596). Photoreceptors are unable to reisomerize all-trans-retinal, formed after photon absorption, back into 11-cis-retinal. To maintain the photoreceptor excitability, retinal is transported to the RPE reisomerized to 11-cis-retinal and transported back to photoreceptors. This process is known as the visual cycle of retinal. Furthermore, the voltage-dependent ion conductance of the apical membrane enables the RPE to stabilize ion composition in the subretinal space, which is essential for the maintenance of photoreceptor excitability (144, 558, 559). ...
elial cells turned upside down with their tips immersed in the pigmented layer of the retina. Going from the pigmented layer into the neural layer, rods and cones have an outer segment joined to an inner segment by a stalk containing a cilium. The inner segment connects to the cell body, or nuclear region, which is continuous with an inner fibre tipped with synaptic endings.. Image showing the position of the retina in the eye. Taken from http://cwx.prenhall.com/bookbind/pubbooks/morris2/ chapter3/medialib/summary/1.html, without permission.. The light absorbing visual pigments are packaged in membrane bound discs within the outer segments. The coupling of the photoreceptor pigments to cellular membranes magnifies the surface area available for light trapping. In rods the discs are discontinuous and stacked like hollow pennies within the plasma membrane. In cones the discs become increasingly smaller towards the end of the cell and their membranes are continuous with the plasma membrane. ...
We have investigated background and bleaching adaptation in vertebrate rods by intracellular recording in the retina of Bufo marinus. Backgrounds and bleaching produce adaptation in photoreceptors and lead to a shift and a compression of the response operating range. Threshold elevation due to backgrounds follows the Rose-DeVries rule at low intensities and the Weber-Fechner rule at high intensities. Threshold elevation due to bleaching is linear almost up to 17% bleached pigment and exponential thereafter. An equivalence can be established between bleaching and backgrounds with respect to threshold elevation, on the one hand, and with respect to response compression, on the other. These equivalences are the same within experimental error. The equivalence, moreover, appears to extend to the complete response curve. These results have implications for psychophysics as well as for photoreceptor transduction.. ...
Visually-Driven Ocular Growth in Mice Requires Functional Rod Photoreceptors. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
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Continued From Above... Before those signals ever reach the brain, however, they must be captured and translated into nerve signals by the various photoreceptor cells of the eye. There are two types of photoreceptor cells that, because of their shapes, are called rods and cones. Rods are sensitive enough to respond to a single photon, the basic unit of light, but together they create only one coarse, gray image, which is just adequate for seeing in poor light. Fine detail and color come from the cones, but they need a lot more light and work best in broad daylight. Inside the human eye, there are eighteen times more rods than cones - arranged in such a way as to produce the best possible combination of night and day vision - and all of them transmitting data to the optic nerve on the way to the brain.. In order to track these visual images within the field of vision, the eye must be capable of quick and extensive movement. For this, each eye is held in place by three pairs of taut, elastic ...
Apparatus and method for providing a structured distribution for charge stored on a photoreceptor element. An optical element located adjacent to the photoreceptor, includes two generally parallel reflecting surfaces, one surface being partially reflecting and one surface being substantially totally reflecting. A narrow collimated beam of radiation, introduced at an angle to the reflecting surfaces, produces multiple reflections between the reflecting surfaces of the optical element. A portion of the collimated beam exits from the cavity through the partially reflecting surface with each reflection therefrom. The resulting array of substantially parallel light beams is arranged to scan a surface of a photoreceptor having a charge stored thereon. The photoreceptor charge in the region of the incident light beam is dissipated by the impinging radiation resulting in a modulation or structuring of the stored charge. This photoreceptor charge modulation can be utilized to improve image reproduction. A filter
Sigma-Aldrich offers abstracts and full-text articles by [Carolina Pinzon-Guzman, Tiaosi Xing, Samuel Shao-Min Zhang, Colin J Barnstable].
Can plants tell time? How do they know when its sunny out? Photoreceptors are specialized cells that communicate this information to plants,...
The pigments in retinal photoreceptor cells absorb varying wavelengths of light, but the central chromophore, the molecule that actually absorbs the photon is identical. Its ability to tune the responsiveness comes from the association with other opsins giving an organism the ability to respond from the near ultraviolet all the way to far red. Interestingly, […]. ...
The pigments in retinal photoreceptor cells absorb varying wavelengths of light, but the central chromophore, the molecule that actually absorbs the photon is identical. Its ability to tune the responsiveness comes from the association with other opsins giving an organism the ability to respond from the near ultraviolet all the way to far red. Interestingly, […]. ...
Zoological Science publishes articles, reviews and editorials that cover the broad and increasingly interdisciplinary field of zoology.
Photosensitive protein complexes of varied light absorption properties which are expressed in the PHOTORECEPTOR CELLS. They are OPSINS conjugated with VITAMIN A-based chromophores. Chromophores capture photons of light, leading to the activation of opsins and a biochemical cascade that ultimately excites the photoreceptor cells ...
NEURON mod files for a Potassium current from the paper: Beech DJ, Barnes S. Characterization of a voltage-gated K+ channel that accelerates the rod response to dim light. Neuron 3:573-81 (1989). Running the kinetics.hoc simulation file will show the activation steady-state, the time constant, and a family of curves generated modeling the same protocol used for Fig.2A of the paper. Under unix systems: to compile the mod files use the command nrnivmodl and run the simulation hoc file with the command nrngui kinetics.hoc Under Windows using NEURON 5.1: to compile the mod files use the mknrndll command. A double click on the simulation file kinetics.hoc will open the simulation window. Questions on the model parameters should be directed to the authors. Questions on how to use this model with NEURON should be directed to [email protected] ...
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Cone cells in the eye are one of the two types of photoreceptor cells, which because of their shapes are called rods and cones. Rods are sensitive enough to respond to a single photon, the basic unit of light, but together they create only one coarse, gray image, which is adequate for seeing in poor light. Fine detail and color come from the cones, but they need a lot more light and work best in broad Continue Scrolling To Read More Below... ...
In the past weeks, we have been working with some 3D models done by another company with 3DSMax 2009, and exported to the 3DS file format, so we can read it. We realized that each model which included Bump Maps, had a wrong map percentage amount in the file.. A note: In the case of Bump Maps, the real map percentage is not stored in the usual Map Percentage (as INT_PERCENTAGE OR FLOAT_PERCENTAGE, chunks 0x0030 or 0x0031), but in the MAT_BUMP_PERCENT (chunk 0xA252) that comes with the material (if you read chunks sequentially instead of by hierarchy, you will normally find it after the MAP_BUMP chunk). A material with a bump percentage of 999 in 3dsMax will report a percentage of 9 in the file. Of course, materials with more usual bump percentages (below 100), will report no bump at all (zero) in the file. In fact, if you export a model with a 90% of bump, and import back to 3DSMax, you will see that the bump texture is assigned correctly, but the bump percentage is 0.. I installed today the ...
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2014). Molecular Biology of the Cell (6th ed.). Garland Science. Williams (2004). Photoreceptor Cell Biology and Inherited ... the term photopigment is applied to opsin-type photoreceptor proteins, specifically rhodopsin and photopsins, the photoreceptor ... The pigments in photoreceptor proteins either change their conformation or undergo photoreduction when they absorb a photon. ... Examples of photoreceptor pigments include: retinal (in rhodopsin) flavin (in cryptochrome) bilin (in phytochrome) In medical ...
... fascin2 found in the retinal photoreceptor cells; fascin3, which is only found in the testes. Fascin binds beta-catenin, and ... T regulatory cell adhesion to antigen presenting dendritic cell causes sequestration of Fascin-1, an actin-bundling protein ... Adams JC (October 2004). "Roles of fascin in cell adhesion and motility". Current Opinion in Cell Biology. 16 (5): 590-596. doi ... leading to reduced T cell priming. This suggests Treg-mediated suppression of antigen presenting cells is a multi-step process ...
Wolfrum, U. (1995). "Centrin in the photoreceptor cells of mammalian retinae". Cell Motility and the Cytoskeleton. 32 (1): 55- ... Cell Biol. 7 (1): 39-45. doi:10.1016/0955-0674(95)80043-3. PMID 7755988. Levy YY, Lai EY, Remillard SP, Heintzelman MB, Fulton ... The majority of centrin in the cell is non-centrosomal whose function is not yet clear. Centrin belongs to the EF-hand ... Paoletti A, Moudjou M, Paintrand M, Salisbury JL, Bornens M (1996). "Most of centrin in animal cells is not centrosome- ...
ipRGCs are photoreceptor cells which are particularly sensitive to the absorption of short-wavelength (blue) visible light and ... Wong KY, Dunn FA, Berson DM (December 2005). "Photoreceptor adaptation in intrinsically photosensitive retinal ganglion cells ... Berson DM (August 2007). "Phototransduction in ganglion-cell photoreceptors". Pflügers Archiv. 454 (5): 849-55. doi:10.1007/ ... Rollag MD, Berson DM, Provencio I (June 2003). "Melanopsin, ganglion-cell photoreceptors, and mammalian photoentrainment". ...
This autoimmune response leads to photoreceptor cell death. It causes progressive vision loss that can lead to blindness. CAR ... Retinal bipolar cells (cells in retina that transmit signals) react with the antibodies, leading to cell death. Although it is ... Autoimmune antibodies target proteins in retinal photoreceptor cells. The proteins targeted as antigenic are recoverin, α‐ ... Corticosteroids cause white blood cell death, lowering their numbers throughout the body. They also cause white blood cells to ...
Photoreceptor cells are around 3 μm in diameter. Without adaptive optics, resolution levels are in the 10-15 μm range. Research ...
Yau KW, Baylor DA (1989). "Cyclic GMP-activated conductance of retinal photoreceptor cells". Annual Review of Neuroscience. 12 ... "Cyclic GMP-activated conductance of retinal photoreceptor cells", 590 citations 1990 "Primary structure and functional ... Hattar, S; Liao HW; Takao M; Berson DM; Yau KW (2002). "Melanopsin-containing retinal ganglion cells: architecture, projections ... "Melanopsin-expressing ganglion cells in primate retina signal colour and irradiance and project to the LGN", 798 citations 2006 ...
Berson DM (August 2007). "Phototransduction in ganglion-cell photoreceptors". Pflügers Archiv. 454 (5): 849-55. doi:10.1007/ ... Cell. 169 (2): 203-215.e13. doi:10.1016/j.cell.2017.03.027. PMC 5479574. PMID 28388406. "Delayed Sleep Phase Syndrome (DSPS)". ... The photopigment of the retinal photosensitive ganglion cells, melanopsin, is excited by light mainly in the blue portion of ... evidence for a novel circadian photoreceptor". The Journal of Neuroscience. 21 (16): 6405-12. doi:10.1523/JNEUROSCI.21-16- ...
It may be a photoreceptor for dark adapted cells. A transient increase in hydration of transmembrane α-helices with a t(1/2) = ... December 2011). "The microbial opsin family of optogenetic tools". Cell. 147 (7): 1446-57. doi:10.1016/j.cell.2011.12.004. PMC ... There are 9 subfamilies in the MR family: Bacteriorhodopsins pump protons out of the cell; Halorhodopsins pump chloride (and ... a prokaryotic photoreceptor". The EMBO Journal. 8 (13): 3963-71. doi:10.1002/j.1460-2075.1989.tb08579.x. PMC 401571. PMID ...
The retina contains photoreceptor cells and other supporting cells. The principle eyes have a complex and unique organization. ... The columnar cells of the vitreous body stand between the lens and the retina, and their nuclei rest next to the retina. Three ... These spiders have been proven to have green and UV photoreceptors, and likely have many other types which allow them to see a ... Depending on the color of flower they see around them, they can secrete a liquid yellow pigment into the body's outer cell ...
Signal Transduction in Photoreceptor Cells: Proceedings of an International Workshop, Held at the Research Centre Jülich, ... ISBN 3540537651 OCLC 24794897 Hargrave, P. A. Photoreceptor Cells. San Diego: Academic Press, 1993. ISBN 9780121852795 OCLC ... In 1983, Hargrave and colleagues in his laboratory published the full amino acid sequence for rhodopsin, a photoreceptor ... Vrabec, Tamara; Arbizo, Violeta; Adamus, Grazyna; McDowell, J Hugh; Hargrave, PA; Donoso, Larry (1989-07-01). "Rod Cell- ...
The rod photoreceptor cells, which are responsible for low-light vision and are orientated in the retinal periphery, are the ... The underlying mechanism involves the progressive loss of rod photoreceptor cells in the back of the eye. This is generally ... Visual acuity and color vision can become compromised due to accompanying abnormalities in the cone photoreceptor cells, which ... An accurate diagnosis of retinitis pigmentosa relies on the documentation of the progressive loss photoreceptor cell function, ...
Studies have shown that lack of rhodopsin kinase will result in photoreceptor cell death. When photoreceptors cells die, they ... Retinal degeneration is a form of the retinal disease caused by the death of photoreceptor cells that present in the back of ... Murakami Y, Notomi S, Hisatomi T, Nakazawa T, Ishibashi T, Miller JW, Vavvas DG (November 2013). "Photoreceptor cell death and ... That is, in retinas exposed to only dim light, calcium levels are high in retinal rod cells and recoverin is bound to and ...
Photoreceptor cell death is the eventual outcome of retinal degeneration. Without proper function of the photoreceptor cells, ... causes photoreceptor cell death and may induce photoreceptor cell loss in transgenic animals expressing truncated rhodopsin. ... In RP photoreceptor cell death is believed to occur by programmed cell death or apoptosis. Retinitis pigmentosa is a ... RP begins with death of rod photoreceptor cells, which are the only cells in the retina to express rhodopsin and which express ...
... "light cells of Hess". These photoreceptor cells have a central intracellular cavity (phaosome) filled with microvilli. As well ... As the digestive cells become full, they release non-living cells of fat into the fluid-filled coelom, where they float freely ... 1970). "Fine structure of photoreceptor cells in the earthworm, Lumbricus Terrestris". Zeitschrift für Zellforschung und ... Each receptor shows a slightly elevated cuticle which covers a group of tall, slender and columnar receptor cells. These cells ...
... both photoreceptors and hair cells) suggests that the two cells are related to one another evolutionarily. Differences between ... the pinealocytes served the same function as photoreceptor cells, such as retinal cells; in many non-mammalian vertebrates, ... A common theory on the evolution of pinealocytes is that they evolved from photoreceptor cells. It is speculated that in ... It has been suggested that pinealocytes are derived from photoreceptor cells. Research has also shown the decline in the number ...
... photoreceptor cells and leftwards migrating parapineal cells, which in zebrafish are crucial for the establishment of brain ... "Xenopus Bsx links daily cell cycle rhythms and pineal photoreceptor fate". Proceedings of the National Academy of Sciences. 107 ... Bsx is expressed following the circadian rhythm and controls photoreceptor cell differentiation. In zebrafish Bsx is required ... Cell Metabolism. 5 (6): 450-63. doi:10.1016/j.cmet.2007.05.007. PMID 17550780. D'Autilia, S.; Broccoli, V.; Barsacchi, G.; ...
The α-tubulin N-acetyltransferase is mainly located in photoreceptor cells. Moreover, ATAT1 is thought to be associated not ... cell division, cellular morphogenesis and force production in eukaryotic cells. There is a constant modulation of the balance ... Cell. 157 (6, p1405-1415, 5 June 2014): 1405-1415. doi:10.1016/j.cell.2014.03.061. PMC 4726456. PMID 24906155. Friedmann, DR; ... Cell. 136 (3): 551-564. doi:10.1016/j.cell.2008.11.043. PMID 19185337. Kalebic, Nereo; Sorrentino, Simona; Perlas, Emerald; ...
The retina comprises numerous pigment cells and photoreceptors; the latter are easily modified flagellated cells, whose ... Sensory cells known as "sensills" on the "lips" or labrum respond to chemical stimuli and are known as chemoreceptors. These ... The body wall consists of a non-cellular outer skin, the cuticula; a single layer of epidermis cells forming an internal skin; ... Unlike a true coelom, a pseudocoel is not fully enclosed by a cell layer derived from the embryonic mesoderm. A coelom is, ...
... which is a layer of cells that nourishes the light sensors or photoreceptors cells of the retina. LCA patients with this form ... By studying how immune cells, also known as T cells, attack other parts of the body, researchers may gain further information ... The initiative targets photoreceptors and retinal ganglion cells. Currently, the AGI funds three research consortia, ... Retinitis pigmentosa (RP) is a group of rare, genetic disorders that involve a breakdown and loss of cells in the retina. Some ...
"Nuclear architecture of rod photoreceptor cells adapts to vision in mammalian evolution". Cell. 137 (2): 356-68. doi:10.1016/j. ... Schardin M, Cremer T, Hager HD, Lang M (1985). "Specific staining of human chromosomes in Chinese hamster x man hybrid cell ... Cell Res. 124 (1): 111-9. CiteSeerX 10.1.1.490.8109. doi:10.1016/0014-4827(79)90261-1. PMID 499376. [2] Interesting information ... Zorn C, Cremer C, Cremer T, Zimmer J (November 1979). "Unscheduled DNA synthesis after partial UV irradiation of the cell ...
High Otx2 levels induce photoreceptor cell fate but not bipolar cell fate. Low levels of Otx2 impair bipolar cell maturation ... It was found that without the Otx2 gene expression there was slow degeneration of photoreceptor cells in this area. Thus, ... Otx2 is a key regulator of the earliest stages of ES cell differentiation. The ectopic expression of Otx2 drives ES cells into ... Otx2 also represses specific retinal fates (such as subtypes of retinal ganglion and horizontal cells) of sister cells to ...
Thus defined, they need not consist of more than one photoreceptor cell. The presence of genetic machinery (the Pax6 and Six ... some cnidaria have genes which in bilateria control the development of a layer of cells that the cnidaria don't even possess. ...
Blanks JC, Johnson LV (1984). "Specific binding of peanut lectin to a class of retinal photoreceptor cells. A species ... Identification of cone cell inner and outer segments and to a lesser extent rod cell inner segments in the mammalian retina. ... The name "peanut agglutinin" originates from its ability to stick together (agglutinate) cells, such as neuraminidase-treated ... Other uses include: Potent anti-T cell activity. Distinguishing between human lymphocyte subsets. ...
Hyperpolarization of the cell causes voltage-gated calcium channels to close. As the calcium level in the photoreceptor cell ... Photoreceptor cells are unusual cells in that they depolarize in response to absence of stimuli or scotopic conditions ( ... The photoreceptor cells involved in vision are the rods and cones. These cells contain a chromophore (11-cis retinal, the ... Hsu, Yi-Te; Molday, Robert S. (1993). "Modulation of the CGMP-gated channel of rod photoreceptor cells by calmodulin". Nature. ...
A transient increase of only 10 °C can destroy retinal photoreceptor cells. If the laser is sufficiently powerful, permanent ... Most of the light is absorbed by melanin pigments in the pigment epithelium just behind the photoreceptors, and causes burns in ...
All photoreceptor cells in the vertebrate eye contain molecules of photoreceptor protein which is a combination of the protein ... April 16, 2009). "Nuclear Architecture of Rod Photoreceptor Cells Adapts to Vision in Mammalian Evolution". Cell. 137 (2): 945- ... photopsin in color vision cells, rhodopsin in night vision cells, and retinal (a small photoreceptor molecule). Retinal ... The retinal must diffuse from the vision cell, out of the eye, and circulate via the blood to the liver where it is regenerated ...
This leads to the hyperpolarization of photoreceptor cells, changing the rate at which they release transmitters. Meta II ( ... Edwards SC (July 1995). "Involvement of cGMP and calcium in the photoresponse in vertebrate photoreceptor cells". The Journal ... and impairs the ability of the cell to degrade non-functioning proteins, which leads to photoreceptor apoptosis. Other ... Thousands of rhodopsin molecules are found in each outer segment disc of the host rod cell. Retinal is produced in the retina ...
The formation of A2E is largely associated with the rod photoreceptor cells. These cells account for approximately 95% of human ... then transported from the photoreceptor cells back to the RPE cells, where it is stored for recycling and future use as retinol ... The 11-cis-retinol is oxidized to 11-cis retinal and transported to photoreceptor cells where it binds to opsin to form ... Without 11-cis-retinal, the rod photoreceptor cells no longer produce all-trans-retinol and production of A2E is halted. The ...
... larvae possess two kinds of photoreceptor cells: Rhabdomeric and ciliary photoreceptor cells. The ciliary ... A rhabdomeric photoreceptor cell forms with a pigment cell a simple eye. A pair of these eyes mediate phototaxis in the early ... It has the simplest eyes in the animal kingdom, each of which consists solely of a photoreceptor cell and a pigment cell. Males ... The ciliary photoreceptor cells resemble molecularly and morphologically the rods and cones of the human eye. Additional, they ...
The adult also has three photoreceptors (ocelli), one median and two lateral. These photoreceptors record the stimulus for the ... Such barnacles feed by extending thread-like rhizomes of living cells into their hosts' bodies from their points of attachment. ... Gwilliam, G.F.; Millecchia, R. J. (January 1975). "Barnacle photoreceptors: Their physiology and role in the control of ... The photoreceptors are likely only capable of sensing the difference between light and dark.[5] This eye is derived from the ...
ON bipolar cells or inhibit (hyperpolarize) OFF bipolar cells. Thus, it is at the photoreceptor-bipolar cell synapse where ... Photoreceptor cell. Functional parts of the rods and cones, which are two of the three types of photosensitive cells in the ... Ganglion cell (non-rod non-cone) photoreceptorsEdit. A non-rod non-cone photoreceptor in the eyes of mice, which was shown to ... A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual ...
Invertebrate photoreceptor - fix, it ain't ocelli. Pages I've created/substantially rewrote. Major. *Mannose 6-phosphate ... I then moved onto other systems to study problems in cell biology, but now work in a hospital). I am a guy. And the 649 is a ...
Calderone, JB; Reese, BE; Jacobs, GH (2003). "Topography of photoreceptors and retinal ganglion cells in the spotted hyena ( ... In vertebrates with three types of cone cells, at low light intensities the rod cells may contribute to color vision. ... when Thomas Young proposed that color vision was a result of three different photoreceptor cells. From the middle of the 19th ... The normal explanation of trichromacy is that the organism's retina contains three types of color receptors (called cone cells ...
Indeed, the most sensitive mechanoreceptors in humans are the hair cells in the cochlea of the inner ear (no relation to the ... A mechanoreceptor, also called mechanoceptor, is a sensory cell that responds to mechanical pressure or distortion. There are ... Other mechanoreceptors than cutaneous ones include the hair cells, which are sensory receptors in the vestibular system of the ... Mechanoreceptors are also present in plant cells where they play an important role in normal growth, development and the ...
Cells. *Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell ( ... Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K ... mechanism involving the transdifferentiation of venous endothelial cells in the eye into lymphatic-like endothelial cells.[2][3 ...
আলোকগ্রাহক কোষ (Photoreceptor cell). *দণ্ড কোষ (Rod cell). *শঙ্কু কোষ (Cone cell) ...
Li ZY, Kljavin IJ, Milam AH (1995). „Rod photoreceptor neurite sprouting in retinitis pigmentosa.". J. Neurosci. 15 (8): 5429- ... 1994). „The human blue opsin promoter directs transgene expression in short-wave cones and bipolar cells in the mouse retina." ...
photoreceptor disc membrane. العمليات الحيوية. • chemical synaptic transmission. • homophilic cell adhesion via plasma membrane ... calcium-dependent cell-cell adhesion via plasma membrane cell adhesion molecules. • التصاق الخلايا. ... Wu Q، Maniatis T (Jul 1999). "A striking organization of a large family of human neural cadherin-like cell adhesion genes". ... photoreceptor connecting cilium. • تشابك عصبي. • postsynaptic membrane. • ...
Cell Tissue Res, letn. 303: 15-25. *↑ Hüpop K. (2000). How do cave animals cope with the food scarcity in caves?. V: Culver D.C ... 2001). Immunocytochemical demonstration of visual pigments in the degenerate retinal and pineal photoreceptors of the blind ... Cell Tissue Res., 235: 393-402. *↑ Schegel P. & Bulog B. (1997). Population-specific behavioral electrosensitivity of the ...
doi:10.1016/j.cell.2007.01.033. PMID 17320505.. *^ a b c Faghihi MA, Modarresi F, Khalil AM, Wood DE, Sahagan BG, Morgan TE, ... Vorinostat treatment slowed photoreceptor degeneration and improved longevity of adult Htt mutant Drosophila.[18] Like TSA, ... The Journal of Cell Biology. 191 (2): 367-81. doi:10.1083/jcb.201008051. PMC 2958468. PMID 20937701.. ... Tested on: mouse (M), only mouse cells (MC), human (H), Drosophila (D), rat (R). Successful treatment: yes (y), yes but with ...
... just as phototransduction is the term given to the signal transduction event by which photoreceptors elicits vision upon ... T cells expressing this receptor are referred to as α:β (or αβ) T cells, though a minority of T cells express an alternate ... The antigen sensitivity is higher in antigen-experienced T cells than in naive T cells. Naive T cells pass through the process ... Antigen presentation stimulates T cells to become either "cytotoxic" CD8+ cells or "helper" CD4+ cells. ...
The role of PA in the cell[edit]. The role of PA in the cell can be divided into three categories: *PA is the precursor for the ... P, Raghu (August 2012). "Lipid signaling in Drosophila photoreceptors". Biochim Biophys Acta. 1821 (8): 1154-1165. doi:10.1016/ ... PA concentrations are maintained at extremely low levels in the cell by the activity of potent LPPs.[6] These convert PA into ... As PA is rapidly converted to DAG, it is very short-lived in the cell. This means that it is difficult to measure PA production ...
Photoreceptor cell. *Hair cell. *Taste bud. *. Anatomy portal. Authority control *TA98: A14.1.00.017 ...
Opsins are proteins and the retinal-binding visual pigments found in the photoreceptor cells in the retinas of eyes. An opsin ... In cone cells the disks are defined by the cell's plasma membrane so that the N-terminus head extends outside of the cell. ... In rod cells the opsin molecules are embedded in the membranes of the disks which are entirely inside of the cell. The N- ... "Cell. 134 (6): 921-31. doi:10.1016/j.cell.2008.09.002. PMC 2632951. PMID 18805086.. ...
Many flowering plants (angiosperms) use a photoreceptor protein, such as phytochrome or cryptochrome,[1] to sense seasonal ... which is informed by retinal light-sensitive ganglion cells, which are not involved in vision. The information travels through ... Fankhauser, Christian (2001). "The Phytochromes, a Family of Red/Far-red Absorbing Photoreceptors". Journal of Biological ... Cryptochromes are another type of photoreceptor that is important in photoperiodism. Cryptochromes absorb blue light and UV-A. ...
... s have specialised light-sensing cells deep in their brains[permanent dead link] that respond to light without input from ... These are backed up in some species by their ability to sense the Earth's geomagnetism through specialised photoreceptors.[149] ... Birds are tetrachromatic, possessing ultraviolet (UV) sensitive cone cells in the eye as well as green, red and blue ones.[88] ... These photo-receptive cells in the hypothalamus are involved in detecting the longer days of spring, and thus regulate breeding ...
J.M. Watson; J.A.M. Graves (1988). "Monotreme Cell-Cycles and the Evolution of Homeothermy". Australian Journal of Zoology. 36 ... Probably as a side-effect of the nocturnal life, mammals lost two of the four cone opsins, photoreceptors in the retina, ... make the interface between the placenta and uterus into a syncytium, i.e. a thin layer of cells with a shared external membrane ... This allows the passage of oxygen, nutrients and waste products, but prevents the passage of blood and other cells that would ...
"Cell Reports. 11 (6): 851-858. doi:10.1016/j.celrep.2015.04.001. PMC 4643944. PMID 25937277.. ... "Bat Eyes Have Ultraviolet-Sensitive Cone Photoreceptors". PLOS ONE. 4 (7): e6390. Bibcode:2009PLoSO...4.6390M. doi:10.1371/ ... Aging Cell. 1 (2): 124-131. doi:10.1046/j.1474-9728.2002.00020.x. PMID 12882342.. ... The membrane has no hair follicles or sweat glands, except between the fingers.[54][56] For bat embryos, apoptosis (cell death ...
Dentate granule cell[edit]. The principal cell type of the dentate gyrus is the granule cell. The dentate granule cell has an ... Cerebellar granule cell[edit]. Main article: Cerebellar granule cell. The granule cells, produced by the rhombic lip, are found ... Together these cells form the glomeruli.[10] Granule cells are subject to feed-forward inhibition: granule cells excite ... Specific functions of different granule cells[edit]. Cerebellum granule cells. David Marr suggested that the granule cells ...
The function of neurons depends upon cell polarity. The distinctive structure of nerve cells allows action potentials to travel ... Synapses are essential to neuronal function: neurons are cells that are specialized to pass signals to individual target cells ... and for these signals to then be received and carried on by post-synaptic neurons or received by effector cells. Nerve cells ... causing voltage changes in the presynaptic cell to induce voltage changes in the postsynaptic cell. The main advantage of an ...
আলোকগ্রাহক কোষ (Photoreceptor cell). *দণ্ড কোষ (Rod cell). *শঙ্কু কোষ (Cone cell) ...
Photoreceptors located in the retina of the eye send information about environmental light through the retinohypothalamic tract ... Gene-transcription feedback loops in individual SCN cells form the molecular basis of biological timekeeping.[13] Circadian ...
Cells. *Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell ( ... Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K ... photoreceptor cells and retinal ganglion cells. Each cell type can be specifically targeted by choosing the appropriate ... The photoreceptor cell bodies 9. External limiting membrane (ELM) Made of zonulae adherens between Müller cells and ...
In 1802, Thomas Young postulated the existence of three types of photoreceptors (now known as cone cells) in the eye, each of ... that the three types of cone photoreceptors could be classified as short-preferring (blue), middle-preferring (green), and long ...
In insects, many neurons have cell bodies that are positioned at the edge of the brain and are electrically passive-the cell ... Photoreceptors on the animal's eyespots provide sensory information on light and dark.[13] ... suggesting the importance of these proto-synaptic proteins for cell to cell communication.[2] The history of ideas on how ... "Neurobiology: molecules, cells, and systems. Wiley-Blackwell. p. 21. ISBN 978-0-632-04496-2. .. .mw-parser-output cite.citation ...
Mosinger, Ogilvie (1998). "Suppression of developmental retinal cell death but not of photoreceptor degeneration in Bax- ... Cell death in arthropods occurs first in the nervous system when ectoderm cells differentiate and one daughter cell becomes a ... "Ferroptosis: An Iron-Dependent Form of Nonapoptotic Cell Death". Cell. 149 (5): 1060-1072. doi:10.1016/j.cell.2012.03.042. Lang ... Programmed cell death (or PCD) is the death of a cell in any form, mediated by an intracellular program. PCD is carried out in ...
망막색소상피세포(Retinal Pigment Epithelium cells, RPE cells)는 망막 감각신경 부분의 바깥에 존재하며, 색소가 있는 세포들을 지칭한다. [1] ... 광수용세포의 바깥 부분 (Photoreceptor Outer Segment, POS)을 먹어치운다.[17] 이는 광수용세포의 자기 재생산(self-renewal)을 유발함으로써[18], 건강한 시각 능력의 유지에 관여한다. ... J Cell Sci Suppl 17: 189-195, 1993. *↑ Tanihara H, Inatani M, and Honda Y. Growth factors and their receptors in the retina and ... J Cell Physiol 197: 453-462, 2003. *↑ Kojima S, Rahner C, Peng S, and Rizzolo LJ. Claudin 5 is transiently expressed during the ...
In these cells, synthesis starts with D-erythrose 4-phosphate and phosphoenolpyruvate, and in photosynthetic cells with carbon ... evidence for a novel circadian photoreceptor". J. Neurosci. 21 (16): 6405-12. PMID 11487664.. ... Light/dark information reaches the suprachiasmatic nuclei from retinal photosensitive ganglion cells of the eyes[81][82] rather ... Reiter RJ (May 1991). "Pineal melatonin: cell biology of its synthesis and of its physiological interactions". Endocr. Rev. 12 ...
Cells. *Photoreceptor cells (Cone cell, Rod cell) → (Horizontal cell) → Bipolar cell → (Amacrine cell) → Retina ganglion cell ( ... Parasol cell, Bistratified cell, Giant retina ganglion cells, Photosensitive ganglion cell) → Diencephalon: P cell, M cell, K ... Media related to Photoreceptor cells at Wikimedia Commons. *NIF Search - Photoreceptor Cell via the Neuroscience Information ... ON bipolar cells or inhibit (hyperpolarize) OFF bipolar cells. Thus, it is at the photoreceptor-bipolar cell synapse where ...
Photoreceptor cells in the Xenopus retina.. Röhlich P1, Szél A.. Author information. 1. Department of Human Morphology and ... This review summarizes our present state of knowledge about spectrally different photoreceptor cell types in the Xenopus retina ... The majority of photoreceptors is represented by rods. Altogether 97-98% of the total rod population consists of the principal ... The classification of the photoreceptors was based on morphology, combined with immunolabelling with various anti-visual ...
The photoreceptor cell-specific nuclear receptor (PNR), also known as NR2E3 (nuclear receptor subfamily 2, group E, member 3), ... September 2000). "The photoreceptor cell-specific nuclear receptor gene (PNR) accounts for retinitis pigmentosa in the Crypto- ... September 2000). "The photoreceptor cell-specific nuclear receptor gene (PNR) accounts for retinitis pigmentosa in the Crypto- ... April 1999). "Identification of a photoreceptor cell-specific nuclear receptor". Proceedings of the National Academy of ...
ON bipolar cells or inhibit (hyperpolarize) OFF bipolar cells. Thus, it is at the photoreceptor-bipolar cell synapse where ... Photoreceptor cell. Functional parts of the rods and cones, which are two of the three types of photosensitive cells in the ... Ganglion cell (non-rod non-cone) photoreceptorsEdit. A non-rod non-cone photoreceptor in the eyes of mice, which was shown to ... A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual ...
Apoptotic photoreceptor cell death in mouse models of retinitis pigmentosa.. C Portera-Cailliau, C H Sung, J Nathans, and R ... Apoptotic photoreceptor cell death in mouse models of retinitis pigmentosa. Message Subject (Your Name) has sent you a message ... In this paper, we report a test of the hypothesis that photoreceptor cell death occurs by an apoptotic mechanism in three mouse ... it remains to be determined whether these mutations lead to photoreceptor cell death through necrotic or apoptotic mechanisms. ...
In the retina of the eye, photoreceptors develop unique sensory cilia. Not much was known about the mechanisms underlying the ... Here, I will discuss the studies that have revealed new knowledge of how photoreceptor cilia regulate their identity and ... we are now beginning to understand the molecular basis of photoreceptor ciliary architecture, ciliary function and its ... formation and function of photoreceptor cilia, largely because of technical limitations and the specific structural and ...
Rod and cone photoreceptor cells express distinct genes for cGMP-gated channels.. Bönigk W1, Altenhofen W, Müller F, Dose A, ... Signal transduction in vertebrate rod and cone photoreceptor cells involves ion channels that are directly gated by the ... Therefore chicken rod and cone cells each express different forms of cGMP-gated channels that are genetically related to each ... Expression in COS-1 cells produces the complete form of both channel polypeptides, whereas Western blot analysis indicates that ...
Fundus autofluorescence and photoreceptor cell rosettes in mouse models.. [Erin Flynn, Keiko Ueda, Emily Auran, Jack M Sullivan ... The decline in A2E levels in the Rdh8(-/-)/Abca4(-/-) mice paralleled reduced photoreceptor cell viability as reflected in ONL ... Hyperautofluorescent puncta in fundus AF images are attributable, in at least some cases, to photoreceptor cell rosettes. ... Hyperautofluorescent puncta in fundus AF images corresponded to photoreceptor cell rosettes in SD-OCT images and histological ...
The renewal of photoreceptor cell outer segments. J Cell Biol 33: 61-72.. *CrossRef, ... Essential function of Drosophila Sec6 in apical exocytosis of epithelial photoreceptor cells. J Cell Biol 169: 635-646.. * ... Crumbs homologue 1 is required for maintenance of photoreceptor cell polarization and adhesion during light exposure. J Cell ... A mutation of early photoreceptor development, mikre oko, reveals cell-cell interactions involved in the survival and ...
Antibodies for proteins involved in eye photoreceptor cell development pathways, according to their Panther/Gene Ontology ... Antibodies for proteins involved in eye photoreceptor cell development pathways; according to their Panther/Gene Ontology ...
Here we show that HDAC6 is constitutively present in the mouse retina, and in the cone-like mouse cell line 661W. In 661W cells ... with TST prevented the inactivation of Prx1 and its preserved activity may exert protective effects in photoreceptor cells. To ... regulation of peroxiredoxin activity may play a significant role in protecting retinal cells and in particular photoreceptors, ... After oxidative stress, exerted by hydrogen peroxide, TST promoted cell survival and the upregulation of heat-shock proteins ...
... in hiPSC-RPE cells exposed to Fe and CSE was sufficient to increase autofluorescent material build-up in these cells. Given ... Using at least three distinct control hiPSC lines, we show that, compared to untreated hiPSC-RPE cells, POS uptake is reduced ... Human induced pluripotent stem cell (hiPSC)-derived RPE, which phagocytoses and degrades POS in culture and can be derived from ... provides a model system to investigate the singular effect of excess Fe and/or cigarette smoke on POS processing by RPE cells. ...
Targeted RP9 ablation and mutagenesis in mouse photoreceptor cells by CRISPR-Cas9.. [Ji-Neng Lv, Gao-Hui Zhou, Xuejiao Chen, ... in 661 W retinal photoreceptor cells in vitro. We found that proliferation and migration were significantly decreased in the ... Precursor messenger RNA (Pre-mRNA) splicing is an essential biological process in eukaryotic cells. Genetic mutations in many ... However, underlying molecular mechanisms of the RP9 mutation causing photoreceptor degeneration remains fully unknown. Here, we ...
Photoreceptor cell degeneration is a feature common to the ... Photoreceptor cell degeneration is a feature common to these ... Photoreceptor Cells / cytology, metabolism*. Pigment Epithelium of Eye / cytology, metabolism*. Retinal Degeneration / ... Cell Death / physiology. Cell Survival / physiology. Docosahexaenoic Acids / metabolism*. Humans. Nerve Degeneration / ... 15165989 - Increased cell death in osteopontin-deficient cardiac fibroblasts occurs by a caspase-3.... 17973839 - Ganglion cell ...
The following pages link to Photoreceptor cell: View (previous 50 , next 50) (20 , 50 , 100 , 250 , 500)*Ependyma ‎ (← links , ... Retrieved from "https://www.wikidoc.org/index.php/Special:WhatLinksHere/Photoreceptor_cell" ... Pages that link to "Photoreceptor cell". ← Photoreceptor cell. Jump to: navigation, search ...
Saylor.orgs Cell Biology/Light Signal Transduction Inside Photoreceptor Cells. From Wikibooks, open books for an open world ... Retrieved from "https://en.wikibooks.org/w/index.php?title=Saylor.org%27s_Cell_Biology/Light_Signal_Transduction_Inside_ ...
However, the alterations induced in the opsin moiety of the rhodopsin molecule and its distribution in the rod cell... ... Retina Light Exposure Photoreceptor Cell Retinal Degeneration Intense Immunoreactivity Supported in part by grant R01 EY01903 ( ... Schnapf JL, Baylor DA (1987) How photoreceptor cells respond to light. Sci Am 256:40-47Google Scholar ... An immunohistochemical study of opsin in photoreceptor cells following light-induced retinal degeneration in the rat. ...
Synaptic Transmission between Photoreceptors and Horizontal Cells in the Turtle Retina Message Subject. (Your Name) has ... The hyperpolarizing response to light of the horizontal cells would then result from a reduction in the amount of transmitter ... Low calcium, high magnesium, and cobalt hyperpolarize the horizontal cell membrane and suppress the response to light, but only ... These observations are consistent with the interpretation that a depolarizing transmitter is released by photoreceptors in ...
Mature photoreceptor cells were estimated to contain, on average, 6.4 X 10(-12) g DNA, 2.3 X 10(-12) g RNA and 42-64 X 10(-12) ... Rod photoreceptor cells dissociated from mature mice retinas. You will receive an email whenever this article is corrected, ... R N Lolley, R H Lee, D G Chase, E Racz; Rod photoreceptor cells dissociated from mature mice retinas.. Invest. Ophthalmol. Vis ... The dissociation procedure provides a population of photoreceptor cells that appears suitable for microscopic, ...
Impaired photoreceptor synaptic terminals, horizontal cell morphology, bipolar cell dendrites, and retinal gliosis in bright ... photoreceptor cells, diminished synaptophysin in the OPL, and altered horizontal cell morphology. ... Abca4−/−Rdh8−/− mice exposed to bright light exhibit pyknosis of photoreceptor cells, diminished synaptophysin in the OPL, and ... Synergistically acting agonists and antagonists of G protein-coupled receptors prevent photoreceptor cell degeneration Yu Chen ...
... photoreceptor,precursor,cells,restore,visual,function,in,mice,with,retinal,degeneration,biological,biology news articles, ... The achievement is based on a novel technology in which the cells are ...The team of scientists found that transplanted ... photoreceptor precursor...Rather than injecting undifferentiated and uncommitted stem cells into...The findings reported in the ... Scientists have successfully transplanted light-sensing cells called p... ...
... and all mice of this line develop both retinal photoreceptor cell and pineal tumors by as early as 2 weeks of age. Cell lines ... Photoreceptor cell tumors in transgenic mice. You will receive an email whenever this article is corrected, updated, or cited ... Photoreceptor-Like Cells in Transgenic Mouse Eye. Embryonic Retinal Tumors in SV40 T-Ag Transgenic Mice Contain CD133+ Tumor- ... K A Howes, J G Lasudry, D M Albert, J J Windle; Photoreceptor cell tumors in transgenic mice.. Invest. Ophthalmol. Vis. Sci. ...
In adult rats, light-induced changes in the amounts of G and arrestin in the photoreceptor cell outer segments … ... Light-stimulated protein movement in rod photoreceptor cells of the rat retina FEBS Lett. 1987 Dec 10;225(1-2):127-32. doi: ... In dark conditions, G was concentrated in the outer segments of photoreceptor cells while in the light G alpha was seen in the ... In adult rats, light-induced changes in the amounts of G and arrestin in the photoreceptor cell outer segments were observed ...
... has changed diagnostics in ophthalmology by visualizing the morphology of retinal cell layers, which play an important role in ... Aberration correction makes it possible to assign the IOS to single photoreceptor cells or rather identify photoreceptor cells ... ERG measures electrical potential changes of photoreceptor cells, inner retinal cells, and ganglion cells in response to ... from the photoreceptor cells. As result, the photoreceptors hyperpolarize and reduce their release of neurotransmitter, which ...
... and cells from each region underwent fluorescent activated cell sorting (FACS). Expression of retinal cell type- specific genes ... and cells from each region underwent fluorescent activated cell sorting (FACS). Expression of retinal cell type- specific genes ... photoreceptors (PRs) and retinal ganglion cells (RGCs) with separate fluorescent markers. Methods: Labeling of macaque (Macaca ... photoreceptors (PRs) and retinal ganglion cells (RGCs) with separate fluorescent markers. Methods: Labeling of macaque (Macaca ...
Effective transplantation of photoreceptor precursor cells selected via cell surface antigen expression. Stem Cells. 2011; 29: ... Defining the integration capacity of embryonic stem cell-derived photoreceptor precursors. Stem Cells. 2012; 30:1424-35. [PMID ... purified photoreceptors. For a clinical application in humans, cell sources other than primary retinal cells have to be ... from pluripotent stem cells, antibodies against cell surface markers that are expressed in photoreceptors but additionally in ...
In addition, adhesion molecules and matrix metalloproteinases were increased in VEGF-treated photoreceptor cells. All these ... These results suggest that quercetin suppressed VEGF-induced excessive inflammatory response in retinal photoreceptor cells by ... VEGF treatment activated angiogenic signaling pathway in photoreceptor cells. ... of this study are to demonstrate the inflammatory protein expression regulated by VEGF using mouse photoreceptor-derived cells ...
The cells expressing Pal were photoreceptor cells in the retina. In the development of the retina, Pal expression begins at P7 ... Electron micrographs of rod photoreceptors. LR White resin-embedded rod photoreceptor cells were labeled with the polyclonal ... No immunoreactive cells were observed at P1. Positive signals were observed in the presumptive photoreceptor outer segments at ... No immunoreactive cells were observed in retina at P1, but the presumptive photoreceptor outer segments showed weak Pal ...
... and amacrine cells; and the ganglion cell layer (GCL), containing primarily ganglion cells. Photoreceptors, bipolar cells, and ... The retina consists of several different cell layers: the outer nuclear layer (ONL), composed of photoreceptor cell bodies; the ... A red arrow indicates developing photoreceptor cells in the photoreceptor layer. A red arrowhead indicates nonspecific staining ... including horizontal cells (Fig.4 D-F), Müller glia (Fig.4 G-I), amacrine cells (Fig.4 J-L), and bipolar cells (Fig.4 M-O). We ...
  • A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual phototransduction . (wikipedia.org)
  • The human retina contains about 120 million rod cells, and 6 million cone cells. (wikipedia.org)
  • Photoreceptor cells in the Xenopus retina. (nih.gov)
  • This review summarizes our present state of knowledge about spectrally different photoreceptor cell types in the Xenopus retina. (nih.gov)
  • We also show that apoptotic death occurs in the retina during normal development, suggesting that different mechanisms can cause photoreceptor death by activating an intrinsic death program in these cells. (pnas.org)
  • In the retina of the eye, photoreceptors develop unique sensory cilia. (mdpi.com)
  • When neural retina is disordered, AF from photoreceptor cells can contribute to noninvasive fundus AF images. (sigmaaldrich.com)
  • Here we show that HDAC6 is constitutively present in the mouse retina, and in the cone-like mouse cell line 661W. (nature.com)
  • Hemocytometer counts of the cell suspensions indicate that, during a series of ten dissociation steps, a total of about 1-2 million intact photoreceptor cells are dissociated from one adult mouse retina, with less than 5% contamination from Müller cells and neurons of the inner retina. (arvojournals.org)
  • The team of scientists found that transplanted photoreceptor precursor cells survived and became integrated into the mouse retina--and that the technique succeeded because the cells were isolated when they had reached a certain level of maturity. (bio-medicine.org)
  • Rather than injecting undifferentiated and uncommitted stem cells into the retina in hopes they would develop into photoreceptors, researchers introduced cells at a somewhat later stage. (bio-medicine.org)
  • These cells are referred to as "precursors": they are immature cells that are "programmed" to be, but have not yet become, functionally mature photoreceptors--the light-sensitive cells in the retina that are essential for sight. (bio-medicine.org)
  • Photoreceptors consist of rods and cones, highly specialized cells that capture light and convert it into chemical signals that travel through the inner retina and optic nerve and on to the brain where signals are converted to the images we see. (bio-medicine.org)
  • Three components contribute to our vision capabilities: the optics of the eye, the light detection by the photoreceptor cells (PRCs), and the processing of the visual information in the neuronal structures of the retina and the brain. (springer.com)
  • Diseases are known to interfere with physiological function of the vision system on all three levels: They may result in failing to form a high-quality image on the retina, loss of the photoreceptor cell function, or deficiencies in the neuronal processing of the visual information. (springer.com)
  • The ability to generate macaque retinas with sortable cell populations would be of great benefit to both basic and translational studies of the primate retina. (frontiersin.org)
  • Retinitis pigmentosa and age-related macular degeneration are groups of degenerative diseases of the retina leading to the death of photoreceptors. (molvis.org)
  • These expression patterns of Pal appeared to be correlated with the development of the photoreceptor outer segments, because in the adult rat retina it was specifically localized in these segments. (jneurosci.org)
  • This novel retina-specific protein was considered to be a new member of the LRR and Ig superfamily and was named Pal (photoreceptor-associated LRR superfamily). (jneurosci.org)
  • Crx , an Otx -like homeobox gene, is expressed primarily in the photoreceptors of the retina and in the pinealocytes of the pineal gland. (jneurosci.org)
  • All of the independent transgenic lines commonly showed lacZ expression in the photoreceptor cells of the retina and in the pinealocytes of the pineal gland. (jneurosci.org)
  • The retina is a very sensitive light detector, and the photoreceptor cells in the retina are essential for vision formation. (jneurosci.org)
  • The vertebrate retina contains two types of photoreceptors, rods and cones. (jneurosci.org)
  • Most of the molecules involved in the phototransduction pathway are expressed specifically in the photoreceptors of the retina and in the pinealocytes of the pineal gland. (jneurosci.org)
  • The pineal gland is related evolutionarily to the photoreceptors in the retina. (jneurosci.org)
  • Correlated firing among major ganglion cell types in primate retina. (duke.edu)
  • Functional connectivity in the retina at the resolution of photoreceptors. (duke.edu)
  • High-sensitivity rod photoreceptor input to the blue-yellow color opponent pathway in macaque retina. (duke.edu)
  • Small bistratified cells (SBCs) in the primate retina carry a major blue-yellow opponent signal to the brain. (duke.edu)
  • It has recently become possible to identify cone photoreceptors in primate retina from multi-electrode recordings of ganglion cell spiking driven by visual stimuli of sufficiently high spatial resolution. (duke.edu)
  • The propagation of visual signals from individual cone photoreceptors through parallel neural circuits was examined in the primate retina. (duke.edu)
  • The objective of this proposal is to determine if ES/iPS cell-derived photoreceptors can be utilised as a therapeutic source of cells to repair the degenerate retina and to model photoreceptor disorders. (europa.eu)
  • First, they observed ectopic nuclei located in the photoreceptor segments of the retina of GRF2-knockout mice, which belong to cone photoreceptor cells and arise postnatally. (biologists.org)
  • This migration defect results in a functional deficiency of the retina, as determined by a significant reduction in the response of cone cells in the absence of GRF2 compared to those of wild type. (biologists.org)
  • In the mouse retina, three different types of photoreceptors provide input to 14 bipolar cell (BC) types. (elifesciences.org)
  • to analyze the connectivity between photoreceptors and bipolar cells in the outer plexiform layer (OPL) of the mouse retina ( Figure 1A ). (elifesciences.org)
  • Introduction The degeneration of neurons and photoreceptors in the retina occur in a number of disorders for which there are currently few therapies, including retinitis pigmentosa, age-related macular degeneration, and glaucoma. (ideaconnection.com)
  • The repair of the retina with replacement cells derived from human embryonic stem cells could thus provide the basis for new approaches for treating a wide variety of retinal degenerations. (ideaconnection.com)
  • After the transduction of light energy into an electrical signal in photoreceptors, the next key task in visual processing is the transmission of an optimized signal to the follower neurons in the retina. (frontiersin.org)
  • Photoreceptors are the most numerous and metabolically demanding cells in the retina. (elifesciences.org)
  • these changes impact nutrient availability for the sensory retina and promote progressive photoreceptor degeneration. (elifesciences.org)
  • The choriocapillaris, Bruch's membrane, RPE, and photoreceptors function as one unit, with the choriocapillaris providing fuel for phototransduction, and Bruch's membrane and RPE cells filtering and regulating the reciprocal exchange of oxygen, nutrients, biomolecules, and metabolic waste products between the circulation and retina. (elifesciences.org)
  • In this study, we describe an in vitro method by which hPSCs can be differentiated into 3D retinas with at least some important features reminiscent of a mature retina, including exuberant outgrowth of outer segment-like structures and synaptic ribbons, photoreceptor neurotransmitter expression, and membrane conductances and synaptic vesicle release properties consistent with possible photoreceptor synaptic function. (utah.edu)
  • The advanced outer segment-like structures reported here support the notion that 3D retina cups could serve as a model for studying mature photoreceptor development and allow for more robust modeling of retinal degenerative disease in vitro. (utah.edu)
  • Retinal progenitor cells were derived from the neural retina of GFP-transgenic pigs and transplanted to the subretinal space of rhodopsin Pro347Leu-transgenic allorecipients, in the early stage of the degeneration and the absence of immune suppression. (lu.se)
  • compensatory neurogenesis mechanisms do not exist to replace all dying cells in the normal retina [ 1 ]. (biomedcentral.com)
  • Labeled protein was displaced as early as 1 hr postinjection from pigment epithelial cell somas into the apical processes, and by 2 hr postinjection was located in the adjacent lamellar whorls characteristic of the mutant rat retina. (rupress.org)
  • Photoreceptor and microglia cell numbers and retina thickness were determined to quantitatively characterize retinal degeneration in ARSG-deficient mice. (uni-bielefeld.de)
  • Photoreceptor loss was accompanied by reactive astrogliosis, reactive microgliosis that was evident in the outer but not inner retina, and elevated expression levels of some lysosomal proteins. (uni-bielefeld.de)
  • In contrast, gene expression profiling and histological data suggest an increased survival of amacrine cells in the postischemic retina of P2Y1R-KO mice. (uni-regensburg.de)
  • An online publication of the December 2001 publication of Nature Neuroscience has reported that, with genetic manipulation, cells from the iris may be able to replace photoreceptor cells in the retina. (preventblindness.org)
  • The procedure caused the iris cells to express rhodopsin, a substance in the retina that adapts the eye to changes in light. (preventblindness.org)
  • Photoreceptor cell-replacement may hold the potential for repair in a completely degenerate retina by reinstating light sensitive cells to form connections that relay information to downstream retinal layers. (ox.ac.uk)
  • Amacrine cells are interneurons in the retina. (unionpedia.org)
  • Cone cells, or cones, are one of three types of photoreceptor cells in the retina of mammalian eyes (e.g. the human eye). (unionpedia.org)
  • Early EAU is defined as the phase prior to day 7 postimmunization before infiltration of inflammatory cells into the retina and/or urea, whereas amplified EAU occurs after day 7, with a peak inflammation on day 14 (Fig. 1 ) revealing heavy infiltration and inflammatory cells in the retina and uvea. (springeropen.com)
  • A photoreceptor cell is a specialized type of neuron found in the retina that is capable of phototransduction . (omicsgroup.org)
  • The OCT data showed a loss of the photoreceptor inner segment/outer segment (IS/OS) junction in the central retina, which correlated well with rod loss but not with cone loss. (city.ac.uk)
  • Well after the total loss of photoreceptors, neurons of the inner retina are known to undergo plastic changes. (edu.au)
  • There was a decrease in size and level of branching of A2, B1 and D type ganglion cells in the degenerated retina at 11 months of age. (edu.au)
  • We propose these changes in ganglion cell morphology could impact the function of individual cells as well as the retinal circuitry in the degenerated retina. (edu.au)
  • The pineal organ in mammals has lost its photoreceptor function and receives information from the retina via sympathetic fibers. (mtak.hu)
  • Our results support the view that RPE cells synthesise and express CFH and are probably a major local source of this protein at the retina/choroid interface, secreting CFH into the interphotoreceptor matrix as well as Bruch's membrane. (elsevier.com)
  • Rod and cone photoreceptors account for 70-80% of all cells in the adult neural retina. (pnas.org)
  • In the retina, six classes of neurons and one class of glia develop from a pool of precursor cells, whose competence decreases during development ( W etts and F raser 1988 ). (genetics.org)
  • Self-renewing, multipotential retinal stem cells (RSCs) reside in the pigmented ciliary epithelium of the peripheral retina in adult mammals. (biologists.org)
  • RSCs can give rise to rhodopsin positive-cells, which can integrate into early postnatal retina, and represent a potentially useful option for cellular therapy. (biologists.org)
  • Structurally, the retina is stratified, i.e., most cells are in distinct bands or layers. (fredshead.info)
  • The following is a short description of the important cell types of the retina. (fredshead.info)
  • Once the photoreceptor neuron converts the photic energy to an electrophysiological signal, it passes this signal on to secondary neurons in the next layer of the retina (e.g., bipolar cells) and ultimately to the brain. (fredshead.info)
  • There is a concentration of cone cells in a highly specialized, region of the retina called the macula. (fredshead.info)
  • Retinitis pigmentosa (RP) is a group of inherited human diseases in which photoreceptor degeneration leads to visual loss and eventually to blindness. (pnas.org)
  • In this paper, we report a test of the hypothesis that photoreceptor cell death occurs by an apoptotic mechanism in three mouse models of RP: retinal degeneration slow (rds) caused by a peripherin mutation, retinal degeneration (rd) caused by a defect in cGMP phosphodiesterase, and transgenic mice carrying a rhodopsin Q344ter mutation responsible for autosomal dominant RP. (pnas.org)
  • Both methods showed extensive apoptosis of photoreceptors in all three mouse models of retinal degeneration. (pnas.org)
  • This study was conducted to study correlations among fundus autofluorescence (AF), RPE lipofuscin accumulation, and photoreceptor cell degeneration and to investigate the structural basis of fundus AF spots. (sigmaaldrich.com)
  • Retinal diseases, such as hereditary retinitis pigmentosa and age-related macular degeneration, are characterized by the progressive loss of photoreceptors. (nature.com)
  • In RP, primary rod degeneration is followed by secondary cone cell death, and in COD cone photoreceptors are the major cells affected and subsequently degenerate. (nature.com)
  • Retinal pigment epithelium (RPE) cell dysfunction is central to the pathogenesis of age-related macular degeneration (AMD), a leading cause of adult blindness. (nature.com)
  • However, underlying molecular mechanisms of the RP9 mutation causing photoreceptor degeneration remains fully unknown. (sigmaaldrich.com)
  • Photoreceptor cell degeneration is a feature common to these diseases, and the death of these cells in many instances seems to involve the closely associated retinal pigment epithelial (RPE) cells. (biomedsearch.com)
  • It appears that, despite severe light-mediated retinal degeneration, anti-opsin immunoreactivity persisted in the photoreceptor cells but with an altered pattern in damaged rod outer segments and photoreceptor perikarya. (springer.com)
  • Transplanted photoreceptor precursor cells restore visual function in mice with retinal degeneration ( Scientists have successfully transplant. (bio-medicine.org)
  • The photoreceptor precursors were transplanted into three different types of mice with retinal degeneration caused by distinct genetic defects involving malfunctioning or degenerating rods. (bio-medicine.org)
  • In the majority of macular and retinal degenerative diseases, such as age-related macular degeneration and retinitis pigmentosa, it is the loss of photoreceptors that leads to blindness. (bio-medicine.org)
  • Royal College of Surgeon (RCS) rats undergo retinal degeneration due to the inability of retinal pigment epithelial (RPE) cells to phagocytose shed outer segments. (ua.es)
  • We explored the effect of introducing Schwann cells to the subretinal space of RCS rats (before the onset of retinal degeneration), by relying on electro-retinogram (ERG) recordings and correlative retinal morphology. (ua.es)
  • Blue light induces photoreceptor apoptosis and causes age-related macular degeneration or retinitis pigmentosa. (molvis.org)
  • Photoreceptor degeneration is an irreversible process that can lead to night blindness and visual field defects and eventually to loss of vision. (molvis.org)
  • The retinal progenitor cells are able to integrate with retinas from a mouse model of retinal degeneration and increase in their expression of photoreceptor-specific markers. (ideaconnection.com)
  • Defects in RPE, photoreceptors, and the choriocapillaris are characteristic of age-related macular degeneration (AMD), a common vision-threatening disease. (elifesciences.org)
  • Development of reliable methods to culture complex retinal tissues from human pluripotent stem cells (hPSCs) could offer a means to study human retinal development, provide a platform to investigate the mechanisms of retinal degeneration and screen for neuroprotective compounds, and provide the basis for cell-based therapeutic strategies. (utah.edu)
  • Transplantation of stem, progenitor, or precursor cells has resulted in photoreceptor replacement and evidence of functional efficacy in rodent models of retinal degeneration. (lu.se)
  • Moreover, recent studies have implicated changes in photoreceptor pH i in dysfunctional Ca 2+ homeostasis and photoreceptor degeneration ( 10 , 83 ), further underscoring the need to understand pH i -[Ca 2+ ] i interactions in the inner segment where the apoptotic machinery is localized. (physiology.org)
  • Mitotic terminally differentiated photoreceptors (PRs) are observed in early retinal degeneration (erd), an inherited canine retinal disease driven by mutations in the NDR kinase STK38L ( NDR2 ). (biomedcentral.com)
  • Furthermore, a recent comprehensive analysis of different rodent retinal mutants, along with a light-induced retinal degeneration model, clearly demonstrated that reactivation of the expression of cell cycle genes did not correlate with PR cell division as determined by ethynyl deoxyuridine incorporation and phospho histone H3 (PHH3) labeling. (biomedcentral.com)
  • Protein synthesis and displacement in photoreceptor and pigment epithelial cells of inbred normal (Fisher) and mutant (RCS) rats with inherited retinal degeneration has been studied by light and electron microscope radioautography. (rupress.org)
  • Arsg knockout mice showed a progressive degeneration of photoreceptor cells starting between 1 and 6 months of age, resulting in the loss of more than 50% of photoreceptor cells in 24-month-old mice. (uni-bielefeld.de)
  • To our knowledge, this is the first study demonstrating that ARSG deficiency results in progressive photoreceptor degeneration and dysregulation of various lysosomal proteins. (uni-bielefeld.de)
  • Kruszewski K, Luellmann-Rauch R, Dierks T, Bartsch U, Damme M. Degeneration of Photoreceptor Cells in Arylsulfatase G-Deficient Mice. (uni-bielefeld.de)
  • Degeneration of Photoreceptor Cells in Arylsulfatase G-Deficient Mice", INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE , vol. 57, 2016, pp. 1120-1131. (uni-bielefeld.de)
  • Abstract Background Retinitis pigmentosa (RP) is an inherited eye disease characterized by the progressive degeneration of rod photoreceptor cells. (escholarship.org)
  • Importantly, its overexpression does not result in photoreceptor degeneration suggesting haploinsufficiency as the underlying cause in human RP patients carrying SP117. (escholarship.org)
  • Conclusion Our data suggest that distinct mutations in Prpf31 can lead to photoreceptor degeneration through different mechanisms, by haploinsufficiency or dominant-negative effects. (escholarship.org)
  • Photoreceptor degeneration due to retinitis pigmentosa (RP) is a primary cause of inherited retinal blindness. (ox.ac.uk)
  • Following transplantation into mice with end-stage retinal degeneration, these cells differentiated into photoreceptors and formed a cell layer connected with host retinal neurons. (ox.ac.uk)
  • In mutant larvae and adults, the highly ordered photoreceptor mosaic is maintained and degeneration is not observed, suggesting that lor functions after the specification of the other photoreceptor subtypes. (uky.edu)
  • Uveitis is one of the major causes of blindness due primarily to retinal tissue damage, especially retinal photoreceptor degeneration, caused by the release of cytokines and various other chemical mediators such as oxygen metabolites [ 1 ]. (springeropen.com)
  • Here, we have investigated in detail, whether ganglion cells are altered at late stages of degeneration, well after the total loss of photoreceptors. (edu.au)
  • Until today, no adequate treatment is available, but efforts are made to gain more knowledge about the mechanism of photoreceptor degeneration. (uni-tuebingen.de)
  • However, during cone degeneration or cone cell stress ICER expression was significantly upregulated in all mutant retinas. (uni-tuebingen.de)
  • Furthermore, satisfactory treatment options are not available for these diseases and the detailed study of murine cone degeneration models is challenging, because rod photoreceptors outnumber cones by far. (uni-tuebingen.de)
  • 1992). In a first step, these cells were characterized with several retinal markers, in order to find out whether these cone-like cells were suitable for the intended cone degeneration model. (uni-tuebingen.de)
  • Thereafter, the cone degeneration of cpfl1 cones was mimicked in 661W cells by either inhibition of the cone phosphodiesterase 6, or activation of the cGMP dependent protein kinase G. Conclusively, the cpfl1-like degeneration of 661W cells may be used for further investigations of cone degeneration mechanisms and to search for neuroprotective substances. (uni-tuebingen.de)
  • Defective phagosome motility and degradation in cell non-autonomous RPE pathogenesis of a dominant macular degeneration. (uclahealth.org)
  • AHI1 is required for photoreceptor outer segment development and is a modifier for retinal degeneration in nephronophthisis. (uclahealth.org)
  • Mutant prominin 1 found in patients with macular degeneration disrupts photoreceptor disk morphogenesis in mice. (uclahealth.org)
  • Macroarray analysis was used to compare equal amounts of cDNA from wild-type and rd/rd (retinal degeneration) mice, collected at P90 when photoreceptor degeneration is virtually complete. (ox.ac.uk)
  • In contrast, the molecular basis of photoreceptor differentiation has been poorly understood. (jneurosci.org)
  • We have shown previously that transplantation of rod precursor cells at a specific stage of development results in integration and differentiation into rod photoreceptors (Nature, 2006) and that this can improve vision in mouse models of visual dysfunction (Nature, 2012). (europa.eu)
  • The mutant phenotype of mbt is characterised by fewer neurones in the brain and the eye, indicating a role of the protein in cell proliferation, differentiation or survival. (biologists.org)
  • Polarized exocytosis plays a major role in development and cell differentiation but the mechanisms that target exocytosis to specific membrane domains in animal cells are still poorly understood. (pubmedcentralcanada.ca)
  • Further evidence of photoreceptor differentiation included the presence of numerous photoreceptor rosettes within GFP-positive grafts, indicative of the development of cellular polarity and self-assembly into rudiments of outer retinal tissue. (lu.se)
  • Based upon these data, we propose a previously undescribed function for tbx2b in photoreceptor cell precursors, to promote the UV cone fate by repressing the rod differentiation pathway. (uky.edu)
  • Besides, previous studies have shown that PCB 1254 exposure can affect the differentiation of retinal layers and adversely damage the photoreceptor cells. (aging-us.com)
  • MiRNAs are endogenous, non-coding, single-stranded RNAs that regulate gene expression through translational repression or mRNA degradation [ 9 ], and are involved in many physiological, pathological, and biochemical processes such as tumorigenesis, organ development, cell proliferation and differentiation, and apoptosis [ 10 ]. (aging-us.com)
  • Photoreceptor differentiation is completed in our culture method in serum-free medium, allowing its examination in a definitive paradigm. (mtak.hu)
  • Through genetic and developmental analysis of Drosophila eye development, we found that the cyclin-dependent kinase-inhibitor Roughex maintains G1 cell cycle exit during differentiation of the R8 class of photoreceptor neurons. (elsevier.com)
  • These findings indicate a neuron-specific defect in cytokinesis and demonstrate a critical role for mitotic cyclin downregulation both to maintain cell cycle exit during neuronal differentiation and to prevent axonal defects following failed cytokinesis. (elsevier.com)
  • this loss of activated STAT3 leads to Rhodopsin expression and rod photoreceptor cell differentiation. (elsevier.com)
  • Thus, SOCS3 can act as a temporal fine-tuner of STAT3 activation during photoreceptor cell differentiation. (elsevier.com)
  • The Maf-family transcription factor Nrl is a key regulator of photoreceptor differentiation in mammals. (pnas.org)
  • The ability to purify a stem cell population and direct the differentiation toward a particular cell lineage is a challenge facing the application of stem cells in regenerative medicine. (biologists.org)
  • This directed RSC differentiation follows the temporal sequence of photoreceptor differentiation in vivo , and the cells exhibit morphology, protein and gene expression consistent with primary cultures of rods in vitro . (biologists.org)
  • The use of stem cells for photoreceptor replacement strategies in humans would require differentiation protocols that can generate highly pure, fate-specified, populations of photoreceptor precursors. (biologists.org)
  • Nir I, Papermaster DS (1986) Immunocytochemical localization of opsin in the inner segment and ciliary plasma membrane of photoreceptors in retinas of rds mutant mice. (springer.com)
  • Rod photoreceptor cells dissociated from mature mice retinas. (arvojournals.org)
  • Intact rod photoreceptors were dissociated from pronase-treated whole retinas of adult mice by repeated passage through a plastic pipette tip. (arvojournals.org)
  • In both light- and dark-adapted retinas, PDE was localized primarily in the outer segments of the photoreceptor cells. (nih.gov)
  • Transplantation of cells into retinas affected by degenerative diseases to replace dying photoreceptors represents a promising therapeutic approach. (molvis.org)
  • Young photoreceptors of 4-day-old mice show the highest capacity to integrate into the retinas of adult mice following grafting. (molvis.org)
  • In situ hybridization and immunohistochemistry showed specificity of Cacna2d4, Kcnv2, and Pcdh21 for photoreceptors in the retinas of young mice. (molvis.org)
  • Cacna2d4, Kcnv2, and Cnga1 were identified as specific for target cells in the retinas of young mice and could serve as candidates for rod photoreceptor enrichment to replace cells in retinal degenerative diseases. (molvis.org)
  • For this technique, the glycosylphosphatidylinositol (GPI)-anchored cell surface molecule ecto-5′-nucleotidase (Nt5e, also termed CD73), expressed by photoreceptors in retinas of 4-day-old mice [ 7 , 8 ], was used. (molvis.org)
  • Normal retinal morphology was found in areas of retinas that had received cell injections. (ua.es)
  • We have a new publication out ( direct link ), Photoreceptor Outer Segment-like Structures in Long-Term 3D Retinas from Human Pluripotent Stem Cells authored by Karl Wahlin , Julien Maruotti , Srinivasa Sripathi , John Ball, Juan Angueyra, Catherin Kim, Rhonda Grebe, Wei Li , myself and Don Zack . (utah.edu)
  • Importantly, we show for the first time in vivo that retinal transcripts are wrongly spliced in adult transgenic retinas expressing AD5 and exhibiting increased apoptosis in rod photoreceptors. (escholarship.org)
  • The researchers conclude that the preliminary study raises "the possibility that [iris] cells constitute a potential source of retinal transplantation in patients with retinal degenerative diseases or damaged retinas. (preventblindness.org)
  • With immunostaining, ICER expression was observed in GCL, INL and in cone photoreceptors of all mutants and corresponding wt retinas. (uni-tuebingen.de)
  • In Nrl −/− retinas, the GFP+ photoreceptors express S-opsin, consistent with the transformation of rod precursors into cones. (pnas.org)
  • We report the gene profiles of freshly isolated flow-sorted GFP+ photoreceptors from wild-type and Nrl −/− retinas at five distinct developmental stages. (pnas.org)
  • There are two main types of photoreceptor cells in most animal retinas. (fredshead.info)
  • Two complementary techniques were used to detect apoptosis-specific internucleosomal DNA fragmentation: agarose gel electrophoresis and in situ labeling of apoptotic cells by terminal dUTP nick end labeling. (pnas.org)
  • NPD1 inhibits oxidative-stress-mediated proinflammatory gene induction and apoptosis, and consequently promotes RPE cell survival. (biomedsearch.com)
  • The Drosophila gene mushroom bodies tiny ( mbt ) encodes a putative p21-activated kinase (PAK), a family of proteins that has been implicated in a multitude of cellular processes including regulation of the cytoskeleton, cell polarisation, control of MAPK signalling cascades and apoptosis. (biologists.org)
  • A critical role for reactive oxygen species (ROS) in photoreceptor apoptosis has been established. (csic.es)
  • Cytosolic calcium levels increased during photoreceptor apoptosis, leading to activation of the calcium-dependent proteases calpains. (csic.es)
  • However, although treatment with the pan-caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp fluoromethyl ketone inhibited caspase activity per se in SNP-treated 661W cells, it did not prevent apoptosis. (csic.es)
  • On the other hand, CR-6 (3,4-dihydro-6-hydroxy-7-methoxy-2,2-dimethyl-1(2H)-benzopyran) acted as a scavenger of ROS and reduced 661W photoreceptor apoptosis induced by SNP by preventing the activation of a pathway in which calpains have a key role. (csic.es)
  • In summary, we report for the first time that both caspases and calpains are involved in 661W photoreceptor apoptosis and that calpain activation can be prevented by the ROS scavenger CR-6. (csic.es)
  • Agents that prevent mitochondrial oxidative stress and photoreceptor apoptosis may help prevent retinal damage and preserve vision in uveitis. (springeropen.com)
  • Apoptosis or retinoblastoma: alternative fates of photoreceptors expressing the HPV-16 E7 gene in the presence or absence of p53. (ac.be)
  • The result showed that PCB 1254 exposure inhibited cell proliferation and increased the apoptosis of the 661w cells, and the dose-response relationship between the retinal development-related genes (SWS1, CRX, Rho), miR-20b expression and PCB 1254 exposure was also discovered. (aging-us.com)
  • Finally, closest to the brain (and farthest from the field of view) is the outer segment, the part of the photoreceptor that absorbs light. (wikipedia.org)
  • Expression in COS-1 cells produces the complete form of both channel polypeptides, whereas Western blot analysis indicates that channels in outer segment membranes are present in a processed form that is significantly shorter than the full-length polypeptide. (nih.gov)
  • Both rod and cone photoreceptors elaborate a specialized structure, the outer segment, to catch the light. (jneurosci.org)
  • The expression of multiple photoreceptor markers by grafted cells included the rod outer segment-specific marker ROM-1. (lu.se)
  • To reveal comprehensive understanding of the physiological properties of the photoreceptors, we focused on the characteristic feature of the morphology of the photoreceptor outer segment. (nii.ac.jp)
  • In RCS photoreceptors, outer segment displacement was slowed from the normal rate before day 17 and at all subsequent stages. (rupress.org)
  • They are synthesized in the cell body, located and transported in the outer segment on common lipid rafts and play a developmental role. (mtak.hu)
  • Synthesis of CFH was not affected by a short-term (2 h) photoreceptor outer segment (POS) treatment. (elsevier.com)
  • Here, I study the molecular mechanisms of photoreceptor outer segment (POS) phagosome formation, motility and maturation in the retinal pigment epithelium (RPE), using molecular biological techniques, cell culture, live cell imaging and, 3D/4D modelling and image analysis. (uclahealth.org)
  • This is done is a specialized part of the photoreceptor cells called the outer segment. (fredshead.info)
  • Kennedy, B. and Malicki, J. (2009), What drives cell morphogenesis: A look inside the vertebrate photoreceptor. (wiley.com)
  • We show that mutations in mbt interfere with photoreceptor cell morphogenesis. (biologists.org)
  • We propose a role for Mbt as a downstream effector of Cdc42 in photoreceptor cell morphogenesis. (biologists.org)
  • Xiong W, Rebay I. Abelson tyrosine kinase is required for Drosophila photoreceptor morphogenesis and retinal epithelial patterning. (uchicago.edu)
  • With recent advances in microscopy techniques and molecular and biochemical approaches, we are now beginning to understand the molecular basis of photoreceptor ciliary architecture, ciliary function and its involvement in human diseases. (mdpi.com)
  • Khanna, H. Photoreceptor Sensory Cilium: Traversing the Ciliary Gate. (mdpi.com)
  • Presentation] Identification and characterization of differentially expressed genes among ciliary type photoreceptor neurons in zebrafish. (nii.ac.jp)
  • In animal models, cells transfected with the gene that produces ciliary neurotrophic factor (CNTF) slowed vision loss. (preventblindness.org)
  • They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. (uchicago.edu)
  • Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. (uchicago.edu)
  • In Annelida two types of photoreceptor cells (PRCs) are regarded as generally present, rhabdomeric and ciliary PRCs. (biomedcentral.com)
  • Live-cell imaging evidence for the ciliary transport of rod photoreceptor opsin by heterotrimeric kinesin-2. (uclahealth.org)
  • Although synaptic feedback regulation of photoreceptors is known to occur in Drosophila, many questions about the underlying molecular mechanisms and physiological implementation remain unclear. (nih.gov)
  • Differential localizations of and requirements for the two Drosophila ninaC kinase/myosins in photoreceptor cells. (rupress.org)
  • 1995 ) Signaling activities of the Drosophila wingless gene are separately mutable and appear to be transduced at the cell surface. (biologists.org)
  • 1992 ) A unique mutation in the Enhancer of split gene complex affects the fates of the mystery cells in the developing Drosophila eye. (biologists.org)
  • A Drosophila photoreceptor cell-specific protein, calphotin, binds calcium and contains a leucine zipper. (unil.ch)
  • The membranous photoreceptor protein opsin contains a pigment molecule called retinal. (wikipedia.org)
  • However, the alterations induced in the opsin moiety of the rhodopsin molecule and its distribution in the rod cell after a photic insult have not been definitively established. (springer.com)
  • Hicks D, Sparrow J, Barnstable CJ (1989) Immunoelectron microscopical examination of the surface distribution of opsin in rat rod photoreceptor cells. (springer.com)
  • Nir I, Papermaster DS (1989) Immunocytochemical localization of opsin in degenerating photoreceptors of RCS rats and rd and rds mice. (springer.com)
  • This observation was confirmed by coimmunostaining of dissociated retinal cells with the lacZ and opsin antibodies. (jneurosci.org)
  • The aggregation of short-wavelength opsin (S-opsin) in the murine photoreceptor cells was observed with immunostaining. (molvis.org)
  • The effect of S-opsin knockdown on ATF4 expression in the murine photoreceptor cell line was also investigated. (molvis.org)
  • In the present study, we investigated the mechanism underlying ER stress in response to exposure to blue LED light using murine photoreceptor cells, with particular emphasis on the involvement of S-opsin. (molvis.org)
  • Fluorescent immunohistochemistry was used to visualize markers for Müller's cells (vimentin and retinaldehyde-binding protein 1), photoreceptors (L-M opsin, rhodopsin, and cytochrome oxidase 2), and the outer limiting membrane (OLM) (zonula occludens 1 and occludin). (city.ac.uk)
  • Hybrid photoreceptors appear that express rod and, to a lesser extent, S-opsin. (mtak.hu)
  • Double-labelling was performed with antibodies against Gpi1 and calbindin-D, glutamine synthetase, RPE65, calretinin and ultraviolet opsin in order to provide positive cell type identification. (ox.ac.uk)
  • rods , cones , and intrinsically photosensitive retinal ganglion cells . (wikipedia.org)
  • The two classic photoreceptor cells are rods and cones, each contributing information used by the visual system to form a representation of the visual world, sight . (wikipedia.org)
  • The three types of cone cell respond (roughly) to light of short, medium, and long wavelengths, so they may respectively be referred to as S-cones, M-cones, and L-cones. (wikipedia.org)
  • In the human visual system, in addition to the photosensitive rods & cones, there are about 2.4 million to 3 million ganglion cells , with 1 to 2% of them being photosensitive. (wikipedia.org)
  • There are currently three known types of photoreceptor cells in mammalian eyes: rods, cones, and intrinsically photosensitive retinal ganglion cells. (wikipedia.org)
  • Utilizing the phase information, we were able to correct ocular aberrations in order to resolve individual cones and could interferometrically measure sub-wavelength length changes of the photoreceptor outer segments (OS) upon optical stimulation. (springer.com)
  • Monte Carlo methods for localization of cones given multielectrode retinal ganglion cell recordings. (duke.edu)
  • The authors then go on to show that the regular nuclear migration of cones through the outer nuclear layer (ONL) towards photoreceptor segments is altered in the absence of GRF2, and, specifically the terminal movement of cone nuclei towards the outer limiting membrane (OLM). (biologists.org)
  • B ) Volume-reconstructed cones and all CBC4 cells. (elifesciences.org)
  • Mechanisms underlying these properties are understood at the molecular level, and phototransduction proteins differentially expressed in the rods and cones contribute to the distinct photoresponses of these photoreceptors. (nii.ac.jp)
  • Although the physiological properties of cones and rods are well known, only a handful of genes have been identified that regulate the specification of photoreceptor subtypes. (uky.edu)
  • In most mammals, rods greatly outnumber cones (95-97% of photoreceptors in mouse and human). (pnas.org)
  • Some extracellular immunoreactivity was observed in the photoreceptor matrix around cones in freshly fixed tissue only, which could possibly reflect a role as a cytokine. (ox.ac.uk)
  • Antibodies against a synthetic peptide specific for the C-terminal amino acid sequence derived from one clone stain outer segments of cone but not rod photoreceptors. (nih.gov)
  • In adult rats, light-induced changes in the amounts of G and arrestin in the photoreceptor cell outer segments were observed both by polyacrylamide gel analysis of purified ROS and by immunocytochemical localization on retinal sections. (nih.gov)
  • In dark conditions, G was concentrated in the outer segments of photoreceptor cells while in the light G alpha was seen in the inner segments and the outer nuclear layer. (nih.gov)
  • Finally, we will develop protocols for generating mature photoreceptor cells with outer segments from human iPS cells in order to model photoreceptor disease. (europa.eu)
  • In photoreceptors, the assembly of signaling molecules into macromolecular complexes is important for phototransduction and maintaining the structural integrity of rod outer segments (ROS). (biologists.org)
  • We investigated interactions between two intracellular messenger ions, protons and calcium (Ca 2+ ), in salamander photoreceptor inner segments loaded with Ca 2+ and pH indicator dyes. (physiology.org)
  • This study examines the specialised arrangement of mitochondria within mouse photoreceptors inner segments by three-dimensional electron microscopy. (vision-research.eu)
  • In photoreceptor inner segments mitochondrial make contact with the plasma membrane through extensive tethering. (vision-research.eu)
  • The extra lamellar material therefore appears to be derived from both rod outer segments and pigment epithelial cells. (rupress.org)
  • The nitration process takes place primarily in the photoreceptor inner segments, an area rich in mitochondria. (springeropen.com)
  • Chen, M, Forrester, JV & Xu, H 2007, ' Synthesis of complement factor H by retinal pigment epithelial cells is down-regulated by oxidized photoreceptor outer segments ', Experimental Eye Research , vol. 84, no. 4, pp. 635-645. (elsevier.com)
  • The photoreceptor cell-specific nuclear receptor (PNR), also known as NR2E3 (nuclear receptor subfamily 2, group E, member 3), is a protein that in humans is encoded by the NR2E3 gene. (wikipedia.org)
  • Furthermore, in response to oxidative stress the redox regulatory protein peroxiredoxin 1 (Prx1) was modulated in 661W cells by HDAC6 inhibition. (nature.com)
  • Mature photoreceptor cells were estimated to contain, on average, 6.4 X 10(-12) g DNA, 2.3 X 10(-12) g RNA and 42-64 X 10(-12) g protein. (arvojournals.org)
  • The aims of this study are to demonstrate the inflammatory protein expression regulated by VEGF using mouse photoreceptor-derived cells and the protective effect of quercetin against VEGF-induced inflammatory response. (mdpi.com)
  • The CRX homeodomain protein is a transactivator of many photoreceptor/pineal-specific genes in vivo , such as rhodopsin and the cone opsins. (jneurosci.org)
  • Plasma membrane domains of polarized cells display distinct protein and lipid compositions. (pubmedcentralcanada.ca)
  • Under ER stress, cells activate the unfolded protein response (UPR) pathway as a self-defense mechanism. (molvis.org)
  • Marian Blanca Ramírez from the CSIC in Spain has been studying the effects of LRRK2, a protein associated with Parkinson's disease, on cell motility. (biologists.org)
  • Researchers from the lab of Lilach O. Lerman (Mayo Clinic, Minnesota, USA) recently sought to discover if cardiovascular risk factors transformed the protein content of extracellular vesicles (EVs) released from mesenchymal stem cells (MSCs). (stemcellsportal.com)
  • Burns, ME & Pugh Jr, EN 2010, ' Lessons from Photoreceptors: Turning off G-Protein Signaling in Living Cells ', Physiology , vol. 25, no. 2, pp. 72-84. (elsevier.com)
  • We used mice, rd1-Thy1, that carry a mutation in the β subunit of phosphodiesterase 6 and a fluorescent protein that labels a subset of ganglion cells and B6-Thy1 control mice. (edu.au)
  • Uninterrupted blood flow and an intricate and architecturally optimized network of photoreceptors, interneurons, glia, and epithelial cells are required for vision. (elifesciences.org)
  • Labeling of pigment epithelial cells in RCS rats was always heavier than in controls. (rupress.org)
  • The RCS pigment epithelial cells thus have an unusual synthetic role and appear to be a source of the extra lamellar material. (rupress.org)
  • 11. A method of producing primate retinal pigment epithelial cells, comprising culturing primate embryonic stem cells as suspended aggregates in a serum-free medium, further culturing the cultured cells under adhesive conditions, and obtaining retinal pigment epithelial cells from the culture. (patentsencyclopedia.com)
  • A novel allele of myosin VIIa reveals a critical function for the C-terminal FERM domain for melanosome transport in retinal pigment epithelial cells. (uclahealth.org)
  • The next wave of research will focus on characterizing the mechanisms that generate photoreceptor precursors from stem cells. (bio-medicine.org)
  • We will build on our achievements in the field of donor photoreceptor cell transplantation and determine if mouse and human ES cells have the potential to provide an efficient source of rod photoreceptor precursors for restoring vision. (europa.eu)
  • A key requirement for the development of retinal stem cell therapy is effective generation and transplantation of ES-derived cone photoreceptor precursors. (europa.eu)
  • 15. The method of claim 13, wherein at least one factor selected from the group consisting of retinoic acid and taurine is added to the culture under adhesive conditions at a stage after the emergence of photoreceptor precursors in the culture. (patentsencyclopedia.com)
  • Our results provide a framework for establishing gene regulatory networks that lead to mature functional photoreceptors from postmitotic precursors. (pnas.org)
  • In rod cells, these together are called rhodopsin. (wikipedia.org)
  • Although mutations in the rhodopsin, peripherin, and cGMP phosphodiesterase genes have been identified in some forms of RP, it remains to be determined whether these mutations lead to photoreceptor cell death through necrotic or apoptotic mechanisms. (pnas.org)
  • The metabolic capacity of dissociated cells was assessed by measuring the utilization of 32P inorganic phosphate for the synthesis of phospholipids and for the light-dependent phosphorylation of rhodopsin. (arvojournals.org)
  • This study shows that with CRX, the iris cells were able to produce rhodopsin, the visual pigment that begins the process of absorbing light and turning it into an electrical signal. (preventblindness.org)
  • The image shows endocytosis of rhodopsin from the rhabdomeres into the cell body. (plos.org)
  • doi:10.1371/journal.pgen.1000377) demonstrates that degradation of internalized rhodopsin in a timely manner is essential for maintaining photoreceptor viability. (plos.org)
  • We show that clonally-derived mouse and human RSC progeny are multipotent and can differentiate into mature rhodopsin-positive cells with high efficiency using combinations of exogenous culture additives known to influence neural retinal development, including taurine and retinoic acid. (biologists.org)
  • The team of scientists found that transplanted photoreceptor precursor. (bio-medicine.org)
  • Farther back still is the inner segment, a specialized part of the cell full of mitochondria. (wikipedia.org)
  • The inner segment region of the photoreceptors contains elongated mitochondria that provide the necessary energy (in addition to aerobic glycolysis) for cellular function. (vision-research.eu)
  • We show that a 2.5-kb Nrl promoter segment directs the expression of enhanced GFP specifically to rod photoreceptors and the pineal gland of transgenic mice. (pnas.org)
  • Cytokine-mediated modulation of MMPs and TIMPs in multipotential neural precursor cells. (biomedsearch.com)
  • Importantly, these results are only achieved using photoreceptor precursor cells that are specified to differentiate into photoreceptors, but are not mature photoreceptors at the time of transplantation. (europa.eu)
  • The present invention further provides a method of producing photoreceptor precursor cells, comprising culturing isolated retinal progenitor cells differentiated from embryonic stem cells, under adhesive conditions, in the presence of a gamma secretase inhibitor, and obtaining a photoreceptor precursor from the culture. (patentsencyclopedia.com)
  • Not much was known about the mechanisms underlying the formation and function of photoreceptor cilia, largely because of technical limitations and the specific structural and functional modifications that cannot be modeled in vitro . (mdpi.com)
  • Because defining the mechanisms of regulation of photoreceptor-specific genes is important to understanding the regulation of cell type specificity, mechanisms of transcriptional regulations of these photoreceptor-specific molecules have been studied extensively. (jneurosci.org)
  • How neurons in the eye feed signals back to photoreceptors to optimize sensitivity to patterns of light appears to be mediated by one or more unconventional mechanisms. (frontiersin.org)
  • Via these mechanisms, horizontal cells control photoreceptor synaptic gain and enhance key aspects of temporal and spatial center-surround receptive field antagonism. (frontiersin.org)
  • However, the exact molecular mechanisms triggered by oxidative stress in photoreceptor cell death remain undefined. (csic.es)
  • We are now investigating the candidate genes by generating knock-out zebrafish to understand the molecular mechanisms for the unique functions of the photoreceptors. (nii.ac.jp)
  • Identifying the principal molecular players and providing an in-depth knowledge of the mechanisms that induce and regulate the underlying PR cell death will provide essential insight into disease progression. (biomedcentral.com)
  • The mechanisms of cell cycle exit by neurons remain poorly understood. (elsevier.com)
  • To avoid this, photosynthetic organisms can actively decrease their light absorption capacity via photoprotective mechanisms that dissipate the excess light as heat, avoiding cell damage. (lpcv.fr)
  • The decline in A2E levels in the Rdh8(-/-)/Abca4(-/-) mice paralleled reduced photoreceptor cell viability as reflected in ONL thinning. (sigmaaldrich.com)
  • Scientists have successfully transplanted light-sensing cells called photoreceptors directly into the eyes of mice and restored their visual function. (bio-medicine.org)
  • Photoreceptor cell tumors in transgenic mice. (arvojournals.org)
  • One line of mice was generated, and all mice of this line develop both retinal photoreceptor cell and pineal tumors by as early as 2 weeks of age. (arvojournals.org)
  • In mice, manipulations of genes in specific retinal cell types can be achieved via traditional germline transgenesis. (frontiersin.org)
  • We have generated transgenic mice, using 5′- and/or 3′-flanking sequences from the mouse Crx homeobox gene fused to the β-galactosidase ( lacZ ) reporter gene, and we have investigated the promoter function of the cell-specific and developmentally regulated expression of Crx . (jneurosci.org)
  • used genetically modified mice to investigate how cells in the eye respond to starvation. (elifesciences.org)
  • While control retinae of P2Y1R-KO mice displayed reduced cell numbers in the ganglion cell and inner nuclear layers, ischemia induced apoptotic death of cells in all retinal layers in both, Wt and P2Y1R-KO mice, but the damage especially on photoreceptors was more pronounced in retinae of P2Y1R-KO mice. (uni-regensburg.de)
  • Function of human pluripotent stem cell-derived photoreceptor progenitors in blind mice. (ox.ac.uk)
  • Scientists have shown that light-sensitive retinal cells, grown in the lab from stem cells, can successfully integrate into the eye when implanted into blind mice. (ajanreginald.com)
  • For other types of photoreceptors, see Photoreceptor (disambiguation) . (wikipedia.org)
  • Apoptotic photoreceptor cell death in mouse models of retinitis pigmentosa. (pnas.org)
  • Here, we utilize the CRISPR/Cas9 system to generate both the Rp9 gene knockout (KO) and point mutation knock in (KI) (Rp9, c.A386T, P.H129L) which is analogous to the reported one in the retinitis pigmentosa patients (RP9, c.A410T, P.H137L) in 661 W retinal photoreceptor cells in vitro. (sigmaaldrich.com)
  • Mutations of various photoreceptor-specific genes have been shown to be responsible for the human genetic retinal disease retinitis pigmentosa (for review, see Dryja and Li, 1995 ). (jneurosci.org)
  • Retinitis pigmentosa refers to a family of inherited photoreceptor degenerations resulting in blindness. (edu.au)
  • In hereditary eye diseases of the Retinitis pigmentosa (RP) type, rod photoreceptors degenerate in a mutation-dependent fashion, followed by mutation independent cone cell death. (uni-tuebingen.de)
  • For this to happen, the release of the excitatory neurotransmitter glutamate from photoreceptors is carefully regulated via horizontal cell feedback, which acts as a thermostat to keep the synaptic transmission in an optimal range during changes to light patterns and intensities. (frontiersin.org)
  • Output signaling from photoreceptors takes place at synaptic complexes comprising the photoreceptor terminal, horizontal cell synaptic processes, and bipolar cell dendrites, where visual information transfer and processing is initiated ( Thoreson and Mangel, 2012 ). (frontiersin.org)
  • We studied the influence of altered ionic conditions on the recycling of synaptic vesicle membrane in frog retinal photoreceptors using horseradish peroxidase to monitor synaptic activity and trace the fate of internalized membrane. (rupress.org)
  • After oxidative stress, exerted by hydrogen peroxide, TST promoted cell survival and the upregulation of heat-shock proteins HSP70 and HSP25 by activation of heat-shock transcription factor 1. (nature.com)
  • Hence, HDAC6 inhibition and the regulation of peroxiredoxin activity may play a significant role in protecting retinal cells and in particular photoreceptors, which are exposed to high levels of reactive oxygen species derived from oxidative stress-induced injuries. (nature.com)
  • TNF-α is a cytokine known to diffuse and upregulate inducible nitric oxide synthase in adjacent cells, resulting in the generation of NO and the subsequent formation of peroxynitrite (ONOO − ) in the mitochondria which leads to mitochondrial oxidative stress. (springeropen.com)
  • We used AO-SLO system to assess macular photoreceptor abnormalities in eyes with resolved or persistent macular edema from retinal vein occlusion (RVO). (nii.ac.jp)
  • RESULTS: The clinically recorded region of macular pigment loss in the macula correlated well with Müller's cell depletion. (city.ac.uk)
  • CONCLUSIONS: We have confirmed our previous finding of Müller's cell loss in MacTel type 2 and have shown that the area of Müller's cell loss matches the area of macular pigment depletion. (city.ac.uk)
  • Most of our central and sharp vision uses macular cone cells. (fredshead.info)
  • Rod and cone photoreceptor cells express distinct genes for cGMP-gated channels. (nih.gov)
  • Gene expression profiling by RNA-Seq demonstrated that RP associated genes, Fscn2 and Bbs2, were down-regulated in the mutated cells. (sigmaaldrich.com)
  • Expression of retinal cell type- specific genes was assessed by quantitative real-time PCR to characterize isolated cell populations. (frontiersin.org)
  • Microarray data of young rod photoreceptors were analyzed using the Database for Annotation, Visualization and Integrated Discovery combined with a literature search to identify genes encoding for proteins containing extracellular domains. (molvis.org)
  • The purification of transplantable donor photoreceptors by cell surface markers would be advantageous in future clinical applications avoiding the need for genetic manipulations of donor cells for the expression of cell type-specific reporter genes. (molvis.org)
  • Interestingly, it recently has been reported that many photoreceptor-specific genes also are expressed in the pineal gland in which Crx is expressed ( Blackshaw and Snyder, 1997 ). (jneurosci.org)
  • In response to blue and red light exposure, this animal-like cryptochrome (aCRY) alters the light-dependent expression of various genes encoding proteins involved in chlorophyll and carotenoid biosynthesis, light-harvesting complexes, nitrogen metabolism, cell cycle control, and the circadian clock. (plantcell.org)
  • Expression of the cell cycle related genes RB1 and E2F1 as well as CDK2,4,6 was up-regulated, but changes were mutation-specific. (biomedcentral.com)
  • Changes in cyclin expression differed across all genes, diseases and time points analyzed, although CCNA1 and CCNE1 expression increased with age in the three models suggesting that there is a dysregulation of cell cycle gene expression in all three diseases. (biomedcentral.com)
  • and then manipulate the iris cell to include any missing genes. (preventblindness.org)
  • In line with a role of this set of homeobox genes in the immature developing pinealocyte, that is, the principal melatonin-producing cell type of the pineal gland, in situ hybridization analyses have revealed that these homeobox genes are highly expressed during early stages in rodent pineal gland development before the appearance of pineal melatonin synthesis [ 13 - 17 ]. (hindawi.com)
  • Exquisitely timed expression of cell-type-specific genes, together with spatial and quantitative precision, depends on the interaction between transcriptional control machinery and extracellular signals ( 2 , 3 ). (pnas.org)
  • The majority of photoreceptors is represented by rods. (nih.gov)
  • Understanding the birth of photoreceptors In 2001, Swaroop's team first showed that the gene NRL, discovered several years earlier in his U-M lab, is essential for the development of rods. (bio-medicine.org)
  • The transformed cells exhibit morphological characteristics and a gene-expression pattern typical of rods, but differentiate in a temporal and spatial pattern consistent with UV-cone development. (uky.edu)
  • Recent research from the labs of Philip EB Nickerson and Valerie Wallace (University Health Network, Toronto, Canada) focused on investigating the effect of the host retinal environment on donor photoreceptor neurite outgrowth. (stemcellsportal.com)
  • To be more specific, photoreceptor proteins in the cell absorb photons , triggering a change in the cell's membrane potential . (wikipedia.org)
  • The different responses of the three types of cone cells are determined by the likelihoods that their respective photoreceptor proteins will absorb photons of different wavelengths. (wikipedia.org)
  • From a utilitarian perspective, it can be also used to selectively label retinal cells via the differential expression of fluorescent proteins. (frontiersin.org)
  • A layer of extracellular matrix proteins, Bruch's membrane, lies adjacent to the choriocapillaris, and a monolayer of retinal pigment epithelium (RPE) cells divides Bruch's membrane from the photoreceptors. (elifesciences.org)
  • G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. (unionpedia.org)
  • The transplanted cells survived and were functional for the duration of the study. (bio-medicine.org)
  • Their primary nutrient source is the choriocapillaris, and both the choriocapillaris and photoreceptors require trophic and functional support from retinal pigment epithelium (RPE) cells. (elifesciences.org)
  • changes in cytosolic ion concentrations provide an integrative feedback about the functional state of the cell to many intracellular processes and pathways. (physiology.org)
  • While stimulating the proliferation of diseased yet functional PRs to maintain the PR layer would likely be therapeutically beneficial in some retinal degenerative diseases, the proliferative potential of PR cells is controversial, and not well understood. (biomedcentral.com)
  • Furthermore, the magnitude of functional improvement was positively correlated with the number of engrafted cells. (ox.ac.uk)
  • The cell (from Latin cella, meaning 'small room') is the basic structural, functional, and biological unit of all known living organisms. (unionpedia.org)
  • Functional experiments were carried out in 661w cells including CCK-8 assay, caspase-3 assay, and the flow cytometry, while the functional role of miR - 20b was further investigated by using the zebrafish model. (aging-us.com)
  • Retinal degenerations leading to loss of photoreceptors are a major cause of untreatable blindness in the EU. (europa.eu)
  • The murine photoreceptor cell line was incubated and exposed to blue LED light (464 nm blue LED light, 450 lx, 3 to 24 h). (molvis.org)
  • Investigations of the mechanism of cone cell death and the search for a neuroprotective compound requires a reliable, high-throughput cell based model system, which we intended to establish using the murine-photoreceptor cell line 661W (Al-Ubaidi et al. (uni-tuebingen.de)
  • Closest to the visual field (and farthest from the brain) is the axon terminal, which releases a neurotransmitter called glutamate to bipolar cells. (wikipedia.org)
  • Parallel visual processing already starts at the very first synapse of the visual system, where photoreceptors distribute the signal onto multiple types of bipolar cells. (elifesciences.org)
  • The precise connectivity rules between photoreceptors and bipolar cell (BC) types determine which signals are available to downstream circuits. (elifesciences.org)
  • Rod bipolar cells (RBCs) are thought to exclusively receive rod input and to feed this signal into the cone pathway via AII amacrine cells (reviewed by Bloomfield and Dacheux, 2001 ). (elifesciences.org)
  • to quantify the connectivity between photoreceptors and bipolar cells in the mouse. (elifesciences.org)
  • A bipolar neuron or bipolar cell, is a type of neuron which has two extensions. (unionpedia.org)
  • Signal transduction in vertebrate rod and cone photoreceptor cells involves ion channels that are directly gated by the internal messenger cGMP. (nih.gov)
  • The vertebrate rod and cone photoreceptors are highly specialized sensory neurons that transduce light into the chemical and electrical signals of the nervous system. (uky.edu)
  • Human and murine embryonic stem [ 9 , 10 ] as well as induced pluripotent stem cells [ 11 , 12 ] were recently demonstrated to differentiate in vitro into photoreceptor-containing cell populations. (molvis.org)
  • Presentation] Multiple types of retinal photoreceptors mediate background adaptation in larval zebrafish. (nii.ac.jp)
  • Presentation] Retinal photoreceptors for body color change in zebrafish. (nii.ac.jp)
  • Tbx2b is required for ultraviolet photoreceptor cell specification during zebrafish retinal development. (uky.edu)
  • Taking advantage of the mosaic organization of photoreceptors in zebrafish, we report the isolation of a mutation resulting in a unique change in photoreceptor cell fate. (uky.edu)
  • In the miR-20b overexpression zebrafish model, we found abnormal retinal morphology characterized by sparse and irregular photoreceptor cells and the thick photoreceptor cell layers. (aging-us.com)
  • Invertebrate photoreceptors in organisms such as insects and molluscs are different in both their morphological organization and their underlying biochemical pathways. (wikipedia.org)
  • Distinct and atypical intrinsic and extrinsic cell death pathways between photoreceptor cell types upon specific ablation of Ranbp2 in cone photoreceptors. (duke.edu)
  • A sensory system consists of sensory neurons (including the sensory receptor cells), neural pathways , and parts of the brain involved in sensory perception . (wikipedia.org)
  • Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade. (uchicago.edu)
  • Robin Ali, University College London (UCL) and President of the European Society of Gene and Cell Therapy (ESGCT) and colleagues from UCL and University of Edinburgh, U.K. coauthored the article entitled "Assessment of AAV Vector Tropisms for Mouse and Human Pluripotent Stem Cell-Derived RPE and Photoreceptor Cells. (eurekalert.org)
  • The research-ers demonstrated the feasibility of using human pluripotent stem cell-derived retinal or-ganoids as an in vitro test system for the development of gene therapy vectors. (eurekalert.org)
  • Incorporating adaptive optics (AO) system into scanning laser ophthalmoscopy (SLO) allowed us for clear imaging of individual cone photoreceptors in living eyes. (nii.ac.jp)
  • Iron (Fe) overload and cigarette smoke exposure are the two environmental factors that are known to affect the lysosomal pathway and impact RPE cell health. (nature.com)
  • VEGF treatment activated angiogenic signaling pathway in photoreceptor cells. (mdpi.com)
  • Considerable progress has been made toward elucidating the physiological and biochemical basis of the phototransduction pathway in photoreceptors. (jneurosci.org)
  • Fat facets is a deubiquitinating enzyme required in a cell communication pathway that limits to eight the number of photoreceptor cells in each facet of the Drososphila compound eye. (biologists.org)
  • We propose that glycolysis in Gpi1-negative cells proceeds entirely through the pentose phosphate pathway, creating NADPH at the cost of organic carbon. (ox.ac.uk)
  • The classification of the photoreceptors was based on morphology, combined with immunolabelling with various anti-visual pigment antibodies and other molecular probes on semithin sections and retinal wholemounts. (nih.gov)
  • Optical coherence tomography (OCT) has changed diagnostics in ophthalmology by visualizing the morphology of retinal cell layers, which play an important role in human vision. (springer.com)
  • This study delineates the molecular events that occur after treatment of the photoreceptor cell line 661W with the nitric oxide donor sodium nitroprusside (SNP). (csic.es)
  • The DPC was oval in shape and large in size, and characterized by features specific to gastropod photoreceptor cells such as massive microvilli, photic vesicles, and a depolarized response. (bioone.org)
  • DRA ommatidia contain homochromatic photoreceptors with high polarization sensitivity (PS) based on precisely aligned microvilli. (biologists.org)
  • For photoreception these cells use either microvilli or cilia. (biomedcentral.com)
  • The former two types of PRCs are always organized as an epithelium with their sensory processes - cilia or microvilli - projecting into an extracellular cavity formed by PRCs and supportive cells. (biomedcentral.com)
  • Cilia are antenna-like extensions of the plasma membrane found in nearly all cell types. (mdpi.com)
  • sec6 mutations cause cell lethality and disrupt plasma membrane growth. (pubmedcentralcanada.ca)
  • The paper, 'Symmetric arrangement of mitochondria: plasma membrane contacts between adjacent photoreceptor cells regulated by Opa1' presents the results of a study led by IoO's Dr Thomas Burgoyne and coauthored by Prof Mike Cheetham. (vision-research.eu)
  • Remarkably, these tethers link mitochondria to the plasma membrane in photoreceptors to form a striking alignment of mitochondria, and even their cristae, between cells. (vision-research.eu)
  • The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates the interior of all cells from the outside environment (the extracellular space). (unionpedia.org)
  • Cell type-specific changes in retinal ganglion cell function induced by rod death and cone reorganization in rats. (duke.edu)
  • We have determined the impact of rod death and cone reorganization on the spatiotemporal receptive fields (RFs) and spontaneous activity of distinct retinal ganglion cell (RGC) types. (duke.edu)
  • Separation of function for classical and ganglion cell photoreceptors with respect to circadian rhythm entrainment and induction of photosomnolence. (biomedsearch.com)
  • In cone cells, there are different types of opsins that combine with retinal to form pigments called photopsins. (wikipedia.org)
  • Therefore chicken rod and cone cells each express different forms of cGMP-gated channels that are genetically related to each other. (nih.gov)
  • The photoreceptor cells are classified into rod and cone cells, which are distinct from each other in photoresponses. (nii.ac.jp)
  • the cone cells are much less affected. (rupress.org)
  • In addition, the findings extend our previous ones demonstrating that rod cells and cone cells differ in their responses to divalent cations in ways that seem likely to be of physiological importance. (rupress.org)
  • Cone cells are more cone shaped. (fredshead.info)