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.
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.
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.
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.
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.-.
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.
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.
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.
'Eye proteins' are structural or functional proteins, such as crystallins, opsins, and collagens, located in various parts of the eye, including the cornea, lens, retina, and aqueous humor, that contribute to maintaining transparency, refractive power, phototransduction, and overall integrity of the visual system.
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)
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.
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.
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.
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.
Enzymes that catalyze the hydrolysis of cyclic GMP to yield guanosine-5'-phosphate.
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.
The process in which light signals are transformed by the PHOTORECEPTOR CELLS into electrical signals which can then be transmitted to the brain.
Recording of electric potentials in the retina after stimulation by light.
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 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.
Adjustment of the eyes under conditions of low light. The sensitivity of the eye to light is increased during dark adaptation.
A genus of the Ambystomatidae family. The best known species are the axolotl AMBYSTOMA MEXICANUM and the closely related tiger salamander Ambystoma tigrinum. They may retain gills and remain aquatic without developing all of the adult characteristics. However, under proper changes in the environment they metamorphose.
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.
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.
A species of the true toads, Bufonidae, becoming fairly common in the southern United States and almost pantropical. The secretions from the skin glands of this species are very toxic to animals.
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)
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.
The absence of light.
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.

Occupancy of the chromophore binding site of opsin activates visual transduction in rod photoreceptors. (1/1358)

The retinal analogue beta-ionone was used to investigate possible physiological effects of the noncovalent interaction between rod opsin and its chromophore 11-cis retinal. Isolated salamander rod photoreceptors were exposed to bright light that bleached a significant fraction of their pigment, were allowed to recover to a steady state, and then were exposed to beta-ionone. Our experiments show that in bleach-adapted rods beta-ionone causes a decrease in light sensitivity and dark current and an acceleration of the dim flash photoresponse and the rate constants of guanylyl cyclase and cGMP phosphodiesterase. Together, these observations indicate that in bleach-adapted rods beta-ionone activates phototransduction in the dark. Control experiments showed no effect of beta-ionone in either fully dark-adapted or background light-adapted cells, indicating direct interaction of beta-ionone with the free opsin produced by bleaching. We speculate that beta-ionone binds specifically in the chromophore pocket of opsin to produce a complex that is more catalytically potent than free opsin alone. We hypothesize that a similar reaction may occur in the intact retina during pigment regeneration. We propose a model of rod pigment regeneration in which binding of 11-cis retinal to opsin leads to activation of the complex accompanied by a decrease in light sensitivity. The subsequent covalent attachment of retinal to opsin completely inactivates opsin and leads to the recovery of sensitivity. Our findings resolve the conflict between biochemical and physiological data concerning the effect of the occupancy of the chromophore binding site on the catalytic potency of opsin. We show that binding of beta-ionone to rod opsin produces effects opposite to its previously described effects on cone opsin. We propose that this distinction is due to a fundamental difference in the interaction of rod and cone opsins with retinal, which may have implications for the different physiology of the two types of photoreceptors.  (+info)

Properties and functional roles of hyperpolarization-gated currents in guinea-pig retinal rods. (2/1358)

1. The inward rectification induced by membrane hyperpolarization was studied in adult guinea-pig rods by the perforated-patch-clamp technique. 2. CsCl blocked the rectification observed in both voltage- and current-clamp recordings at voltages negative to -60 mV, while BaCl2 blocked the inward relaxation observed at voltages positive to -60 mV. The current activated at -90 mV had a low selectivity between sodium and potassium and reversed at -31.0 mV. 3. These observations suggest that two inward rectifiers are present in guinea-pig rods: a hyperpolarization-activated (Ih) and a hyperpolarization-deactivated (Ikx) current. The functional roles of Ih and Ikx were evaluated by stimulating rods with currents sinusoidally modulated in time. 4. Rods behave like bandpass amplifiers, with a peak amplification of 1.5 at about 2 Hz. For hyperpolarizations that mainly gate Ikx, amplification and phase shifts are fully accounted for by a rod membrane analogue model that includes an inductance. For hyperpolarizations that also gate Ih, a harmonic distortion became apparent. 5. Bandpass filtering and amplification of rod signals, associated with Ih and Ikx gating by membrane hyperpolarization, are strategically located to extend, beyond the limits imposed by the slow phototransductive cascade, the temporal resolution of signals spreading to the rod synapse.  (+info)

Formate-induced inhibition of photoreceptor function in methanol intoxication. (3/1358)

Formic acid is the toxic metabolite responsible for the retinal and optic nerve toxicity produced in methanol intoxication. Previous studies in our laboratory have documented formate-induced retinal dysfunction and histopathology in a rodent model of methanol intoxication. The present studies define the time and concentration dependence of formate-induced retinal toxicity in methanol-intoxicated rats. Retinal function was assessed 24, 48, and 72 h after the initial dose of methanol by flicker electroretinographic measurements. Retinal histopathology was assessed at the same time intervals. Rod- and cone-mediated electroretinogram (ERG) responses were attenuated in a formate concentration- and time-dependent manner, and both retinal sensitivity and maximal responsiveness to light were diminished. Attenuation of UV-cone-mediated responses was temporally delayed in comparison to the functional deficits observed in the 15 Hz/510 nm responses, which have a rod-mediated component and occurred at significantly higher formate concentrations. Both 15 Hz/510 nm and UV-cone-mediated ERG responses were undetectable by 72 h; however, if light intensity was increased, a retinal ERG response could be recorded, indicating that photoreceptor function was profoundly attenuated, but not abolished, under these intoxication conditions. Functional changes preceded structural alterations. Histopathological changes were most pronounced in the outer retina with evidence of inner segment swelling, photoreceptor mitochondrial disruption, and the appearance of fragmented photoreceptor nuclei in the outer nuclear layer. The nature of both the functional and structural alterations observed are consistent with formate-induced inhibition of mitochondrial energy production, resulting in photoreceptor dysfunction and pathology.  (+info)

Sensitivity and kinetics of mouse rod flash responses determined in vivo from paired-flash electroretinograms. (4/1358)

1. Electroretinograms (ERGs) were recorded corneally from C57BL/6J mice using a paired-flash procedure in which a brief test flash at time zero was followed at time tprobe by a bright probe flash of fixed strength, and in which the probe response amplitude was determined at time t = tprobe + 6 ms. Probe responses obtained in a series of paired-flash trials were analysed to derive A(t), a family of amplitudes that putatively represents the massed response of the rod photoreceptors to the test flash. A central aim was to obtain a mathematical description of the normalized derived response A(t)/Amo as a function of Itest, the test flash strength. 2. With fixed tprobe (80 <= tprobe <= 1200 ms), A(t)/Amo was described by the saturating exponential function [1 - exp(-ktItest)], where kt is a time-dependent sensitivity parameter. For t = 86 ms, a time near the peak of A(t), k86 was 7.0 +/- 1.2 (scotopic cd s m-2)-1 (mean +/- s. d.; n = 4). 3. A(t)/Amo data were analysed in relation to the equation below, a time-generalized form of the above exponential function in which (k86Itest) is replaced by the product [k86Itestu(t)], and where u(t) is independent of the test flash strength. The function u(t) was modelled as the product of a scaling factor gamma, an activation term 1 - exp[-alpha(t - td)2]), and a decay term exp(-t/tauomega): A(t)/Amo = 1 - exp[-k86Itestu(t)]; u(t) = gamma(1 - exp[-alpha(t - td)2](exp(-t/tauomega) where td is a brief delay, tauomega is an exponential time constant, and alpha characterizes the acceleration of the activation term. For Itest up to approximately 2.57 scotopic cd s m-2, the overall time course of A(t) was well described by the above equation with gamma = 2.21, td = 3.1 ms, tauomega = 132 ms and alpha = 2.32 x 10-4 ms-2. An approximate halving of alpha improved the fit of the above equation to ERG a-wave and A(t)/Amo data obtained at t about 0-20 ms. 4. Kinetic and sensitivity properties of A(t) suggest that it approximates the in vivo massed photocurrent response of the rods to a test flash, and imply that u(t) in the above equation is the approximate kinetic description of a unit, i.e. single photon, response.  (+info)

Abnormal photoresponses and light-induced apoptosis in rods lacking rhodopsin kinase. (5/1358)

Phosphorylation is thought to be an essential first step in the prompt deactivation of photoexcited rhodopsin. In vitro, the phosphorylation can be catalyzed either by rhodopsin kinase (RK) or by protein kinase C (PKC). To investigate the specific role of RK, we inactivated both alleles of the RK gene in mice. This eliminated the light-dependent phosphorylation of rhodopsin and caused the single-photon response to become larger and longer lasting than normal. These results demonstrate that RK is required for normal rhodopsin deactivation. When the photon responses of RK-/- rods did finally turn off, they did so abruptly and stochastically, revealing a first-order backup mechanism for rhodopsin deactivation. The rod outer segments of RK-/- mice raised in 12-hr cyclic illumination were 50% shorter than those of normal (RK+/+) rods or rods from RK-/- mice raised in constant darkness. One day of constant light caused the rods in the RK-/- mouse retina to undergo apoptotic degeneration. Mice lacking RK provide a valuable model for the study of Oguchi disease, a human RK deficiency that causes congenital stationary night blindness.  (+info)

Reciprocity between light intensity and rhodopsin concentration across the rat retina. (6/1358)

1. If a purpose of photostasis - absorption of a constant number of photons by the retina, regardless of incident light levels - is to maintain rods at saturation during the light period, then in retinal regions where light intensity is low, rhodopsin concentration should be high, and vice versa. 2. Our ocular transmission photometric measurements revealed that the distribution of light intensity across the rat retina was not as simple as had been thought and, furthermore, that the local concentration of rhodopsin had a high negative correlation with the light intensity. 3. The reciprocity between these two parameters leads to nearly uniform rates of photon absorption in rods across the retina.  (+info)

Regulation of mammalian circadian behavior by non-rod, non-cone, ocular photoreceptors. (7/1358)

Circadian rhythms of mammals are entrained by light to follow the daily solar cycle (photoentrainment). To determine whether retinal rods and cones are required for this response, the effects of light on the regulation of circadian wheel-running behavior were examined in mice lacking these photoreceptors. Mice without cones (cl) or without both rods and cones (rdta/cl) showed unattenuated phase-shifting responses to light. Removal of the eyes abolishes this behavior. Thus, neither rods nor cones are required for photoentrainment, and the murine eye contains additional photoreceptors that regulate the circadian clock.  (+info)

Is the rod visual field temporally homogeneous? (8/1358)

Cone vision has been shown to be temporally inhomogeneous across the visual field. In the periphery, contrast sensitivity is lower for low temporal frequencies and higher for high temporal frequencies. Here we ask a similar question for rod vision at mesopic luminances. Isolation is obtained by testing a well documented rod monochromat. We show that the rod visual field exhibits only a modest degree of temporal inhomogeneity.  (+info)

Retinal rod photoreceptor cells are specialized neurons in the retina of the eye that are primarily responsible for vision in low light conditions. They contain a light-sensitive pigment called rhodopsin, which undergoes a chemical change when struck by a single photon of light. This triggers a cascade of biochemical reactions that ultimately leads to the generation of electrical signals, which are then transmitted to the brain via the optic nerve.

Rod cells do not provide color vision or fine detail, but they allow us to detect motion and see in dim light. They are more sensitive to light than cone cells, which are responsible for color vision and detailed sight in bright light conditions. Rod cells are concentrated at the outer edges of the retina, forming a crescent-shaped region called the peripheral retina, with fewer rod cells located in the central region of the retina known as the fovea.

Photoreceptor cells are specialized neurons in the retina of the eye that convert light into electrical signals. These cells consist of two types: rods and cones. Rods are responsible for vision at low light levels and provide black-and-white, peripheral, and motion sensitivity. Cones are active at higher light levels and are capable of color discrimination and fine detail vision. Both types of photoreceptor cells contain light-sensitive pigments that undergo chemical changes when exposed to light, triggering a series of electrical signals that ultimately reach the brain and contribute to visual perception.

A rod cell outer segment is a specialized structure in the retina of the eye that is responsible for photoreception, or the conversion of light into electrical signals. Rod cells are one of the two types of photoreceptor cells in the retina, with the other type being cone cells. Rod cells are more sensitive to light than cone cells and are responsible for low-light vision and peripheral vision.

The outer segment of a rod cell is a long, thin structure that contains stacks of discs filled with the visual pigment rhodopsin. When light hits the rhodopsin molecules in the discs, it causes a chemical reaction that leads to the activation of a signaling pathway within the rod cell. This ultimately results in the generation of an electrical signal that is transmitted to the brain via the optic nerve.

The outer segment of a rod cell is constantly being regenerated and broken down through a process called shedding and renewal. The tips of the outer segments are shed and phagocytosed by cells called retinal pigment epithelial (RPE) cells, which help to maintain the health and function of the rod cells.

Rhodopsin, also known as visual purple, is a light-sensitive pigment found in the rods of the vertebrate retina. It is a complex protein molecule made up of two major components: an opsin protein and retinal, a form of vitamin A. When light hits the retinal in rhodopsin, it changes shape, which initiates a series of chemical reactions leading to the activation of the visual pathway and ultimately results in vision. This process is known as phototransduction. Rhodopsin plays a crucial role in low-light vision or scotopic vision.

Transducin is a G protein found in the rod cells of the retina and plays a crucial role in the visual signal transduction pathway. It is responsible for converting the light-induced isomerization of rhodopsin into a biochemical signal, which ultimately leads to the activation of downstream effectors and the generation of a neural response.

Transducin has three subunits: alpha (Tα), beta (Tβ), and gamma (Tγ). When light activates rhodopsin, it interacts with the Tα subunit, causing it to exchange GDP for GTP and dissociate from the Tβγ complex. The activated Tα then interacts with a downstream effector called phosphodiesterase (PDE), which leads to the hydrolysis of cGMP and the closure of cGMP-gated ion channels in the plasma membrane. This results in the hyperpolarization of the rod cell, which is the initial step in the visual signal transduction pathway.

Overall, transducin is a key player in the conversion of light energy into neural signals, allowing us to see and perceive our visual world.

Photoreceptor cells in vertebrates are specialized types of neurons located in the retina of the eye that are responsible for converting light stimuli into electrical signals. These cells are primarily responsible for the initial process of vision and have two main types: rods and cones.

Rods are more numerous and are responsible for low-light vision or scotopic vision, enabling us to see in dimly lit conditions. They do not contribute to color vision but provide information about the shape and movement of objects.

Cones, on the other hand, are less numerous and are responsible for color vision and high-acuity vision or photopic vision. There are three types of cones, each sensitive to different wavelengths of light: short (S), medium (M), and long (L) wavelengths, which correspond to blue, green, and red, respectively. The combination of signals from these three types of cones allows us to perceive a wide range of colors.

Both rods and cones contain photopigments that consist of a protein called opsin and a light-sensitive chromophore called retinal. When light hits the photopigment, it triggers a series of chemical reactions that ultimately lead to the generation of an electrical signal that is transmitted to the brain via the optic nerve. This process enables us to see and perceive our visual world.

Retinal cone photoreceptor cells are specialized neurons located in the retina of the eye, responsible for visual phototransduction and color vision. They are one of the two types of photoreceptors, with the other being rods, which are more sensitive to low light levels. Cones are primarily responsible for high-acuity, color vision during daylight or bright-light conditions.

There are three types of cone cells, each containing different photopigments that absorb light at distinct wavelengths: short (S), medium (M), and long (L) wavelengths, which correspond to blue, green, and red light, respectively. The combination of signals from these three types of cones allows the human visual system to perceive a wide range of colors and discriminate between them. Cones are densely packed in the central region of the retina, known as the fovea, which provides the highest visual acuity.

The retina is the innermost, light-sensitive layer of tissue in the eye of many vertebrates and some cephalopods. It receives light that has been focused by the cornea and lens, converts it into neural signals, and sends these to the brain via the optic nerve. The retina contains several types of photoreceptor cells including rods (which handle vision in low light) and cones (which are active in bright light and are capable of color vision).

In medical terms, any pathological changes or diseases affecting the retinal structure and function can lead to visual impairment or blindness. Examples include age-related macular degeneration, diabetic retinopathy, retinal detachment, and retinitis pigmentosa among others.

Eye proteins, also known as ocular proteins, are specific proteins that are found within the eye and play crucial roles in maintaining proper eye function and health. These proteins can be found in various parts of the eye, including the cornea, iris, lens, retina, and other structures. They perform a wide range of functions, such as:

1. Structural support: Proteins like collagen and elastin provide strength and flexibility to the eye's tissues, enabling them to maintain their shape and withstand mechanical stress.
2. Light absorption and transmission: Proteins like opsins and crystallins are involved in capturing and transmitting light signals within the eye, which is essential for vision.
3. Protection against damage: Some eye proteins, such as antioxidant enzymes and heat shock proteins, help protect the eye from oxidative stress, UV radiation, and other environmental factors that can cause damage.
4. Regulation of eye growth and development: Various growth factors and signaling molecules, which are protein-based, contribute to the proper growth, differentiation, and maintenance of eye tissues during embryonic development and throughout adulthood.
5. Immune defense: Proteins involved in the immune response, such as complement components and immunoglobulins, help protect the eye from infection and inflammation.
6. Maintenance of transparency: Crystallin proteins in the lens maintain its transparency, allowing light to pass through unobstructed for clear vision.
7. Neuroprotection: Certain eye proteins, like brain-derived neurotrophic factor (BDNF), support the survival and function of neurons within the retina, helping to preserve vision.

Dysfunction or damage to these eye proteins can contribute to various eye disorders and diseases, such as cataracts, age-related macular degeneration, glaucoma, diabetic retinopathy, and others.

Retinal degeneration is a broad term that refers to the progressive loss of photoreceptor cells (rods and cones) in the retina, which are responsible for converting light into electrical signals that are sent to the brain. This process can lead to vision loss or blindness. There are many different types of retinal degeneration, including age-related macular degeneration, retinitis pigmentosa, and Stargardt's disease, among others. These conditions can have varying causes, such as genetic mutations, environmental factors, or a combination of both. Treatment options vary depending on the specific type and progression of the condition.

Rhodopsin, also known as visual purple, is a light-sensitive protein found in the rods of the eye's retina. It is a type of opsin, a class of proteins that are activated by light and play a crucial role in vision. Rhodopsin is composed of two parts: an apoprotein called opsin and a chromophore called 11-cis-retinal. When light hits the retina, it changes the shape of the 11-cis-retinal, which in turn activates the rhodopsin protein. This activation triggers a series of chemical reactions that ultimately lead to the transmission of a visual signal to the brain. Rhodopsin is highly sensitive to light and allows for vision in low-light conditions.

In the context of medical terminology, "light" doesn't have a specific or standardized definition on its own. However, it can be used in various medical terms and phrases. For example, it could refer to:

1. Visible light: The range of electromagnetic radiation that can be detected by the human eye, typically between wavelengths of 400-700 nanometers. This is relevant in fields such as ophthalmology and optometry.
2. Therapeutic use of light: In some therapies, light is used to treat certain conditions. An example is phototherapy, which uses various wavelengths of ultraviolet (UV) or visible light for conditions like newborn jaundice, skin disorders, or seasonal affective disorder.
3. Light anesthesia: A state of reduced consciousness in which the patient remains responsive to verbal commands and physical stimulation. This is different from general anesthesia where the patient is completely unconscious.
4. Pain relief using light: Certain devices like transcutaneous electrical nerve stimulation (TENS) units have a 'light' setting, indicating lower intensity or frequency of electrical impulses used for pain management.

Without more context, it's hard to provide a precise medical definition of 'light'.

Photoreceptor cells in invertebrates are specialized sensory neurons that convert light stimuli into electrical signals. These cells are primarily responsible for the ability of many invertebrates to detect and respond to light, enabling behaviors such as phototaxis (movement towards or away from light) and vision.

Invertebrate photoreceptor cells typically contain light-sensitive pigments that absorb light at specific wavelengths. The most common type of photopigment is rhodopsin, which consists of a protein called opsin and a chromophore called retinal. When light hits the photopigment, it changes the conformation of the chromophore, triggering a cascade of molecular events that ultimately leads to the generation of an electrical signal.

Invertebrate photoreceptor cells can be found in various locations throughout the body, depending on their function. For example, simple eyespots containing a few photoreceptor cells may be scattered over the surface of the body in some species, while more complex eyes with hundreds or thousands of photoreceptors may be present in other groups. In addition to their role in vision, photoreceptor cells can also serve as sensory organs for regulating circadian rhythms, detecting changes in light intensity, and mediating social behaviors.

Arrestin is a type of protein that plays a crucial role in regulating the signaling of G protein-coupled receptors (GPCRs) in cells. These receptors are involved in various cellular responses to hormones, neurotransmitters, and other signaling molecules.

When a signaling molecule binds to a GPCR, it activates the receptor and triggers a cascade of intracellular events, including the activation of G proteins. Arrestin binds to the activated GPCR and prevents further interaction with G proteins, effectively turning off the signal.

There are two main types of arrestins: visual arrestin (or rod arrestin) and non-visual arrestins (which include β-arrestin1 and β-arrestin2). Visual arrestin is primarily found in the retina and plays a role in regulating the light-sensitive proteins rhodopsin and cone opsin. Non-visual arrestins, on the other hand, are expressed throughout the body and regulate various GPCRs involved in diverse physiological processes such as cell growth, differentiation, and migration.

By modulating GPCR signaling, arrestins help maintain proper cellular function and prevent overactivation of signaling pathways that could lead to disease. Dysregulation of arrestin function has been implicated in various pathologies, including cancer, cardiovascular diseases, and neurological disorders.

G-Protein-Coupled Receptor Kinase 1 (GRK1) is a serine/threonine kinase that specifically phosphorylates and desensitizes G-protein-coupled receptors (GPCRs) upon agonist activation. GRK1 plays a crucial role in the regulation of GPCR signaling, which is involved in various physiological processes, including sensory perception, neurotransmission, and hormonal regulation.

GRK1 is primarily expressed in the retina and testis, where it regulates the activity of rhodopsin and β-adrenergic receptors, respectively. The kinase activity of GRK1 leads to the recruitment of arrestin proteins, which uncouple the receptor from its G protein, thereby terminating the signaling response. Additionally, GRK1-mediated phosphorylation creates binding sites for β-arrestins, leading to receptor internalization and subsequent degradation or recycling.

Mutations in GRK1 have been associated with various diseases, including retinitis pigmentosa, a genetic disorder that causes progressive vision loss. Therefore, understanding the function and regulation of GRK1 is essential for developing therapeutic strategies targeting GPCR-mediated diseases.

3',5'-Cyclic guanosine monophosphate (cGMP) phosphodiesterases are a group of enzymes that play a role in regulating the levels of cGMP, an important intracellular signaling molecule involved in various biological processes. These enzymes catalyze the hydrolysis of cGMP to 5'-GMP, thereby terminating cGMP-mediated signals within cells.

There are several isoforms of cGMP phosphodiesterases, which differ in their regulatory properties, substrate specificity, and cellular distribution. These enzymes can be activated or inhibited by various factors, including drugs, hormones, and neurotransmitters, and play a crucial role in modulating the activity of cGMP-dependent signaling pathways in different tissues and organs.

Dysregulation of cGMP phosphodiesterase activity has been implicated in various diseases, including cardiovascular disorders, pulmonary hypertension, neurodegenerative diseases, and cancer. Therefore, these enzymes are considered important targets for the development of novel therapeutic strategies for the treatment of these conditions.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Ocular vision refers to the ability to process and interpret visual information that is received by the eyes. This includes the ability to see clearly and make sense of the shapes, colors, and movements of objects in the environment. The ocular system, which includes the eye and related structures such as the optic nerve and visual cortex of the brain, works together to enable vision.

There are several components of ocular vision, including:

* Visual acuity: the clarity or sharpness of vision
* Field of vision: the extent of the visual world that is visible at any given moment
* Color vision: the ability to distinguish different colors
* Depth perception: the ability to judge the distance of objects in three-dimensional space
* Contrast sensitivity: the ability to distinguish an object from its background based on differences in contrast

Disorders of ocular vision can include refractive errors such as nearsightedness or farsightedness, as well as more serious conditions such as cataracts, glaucoma, and macular degeneration. These conditions can affect one or more aspects of ocular vision and may require medical treatment to prevent further vision loss.

Electroretinography (ERG) is a medical test used to evaluate the functioning of the retina, which is the light-sensitive tissue located at the back of the eye. The test measures the electrical responses of the retina to light stimulation.

During the procedure, a special contact lens or electrode is placed on the surface of the eye to record the electrical activity generated by the retina's light-sensitive cells (rods and cones) and other cells in the retina. The test typically involves presenting different levels of flashes of light to the eye while the electrical responses are recorded.

The resulting ERG waveform provides information about the overall health and function of the retina, including the condition of the photoreceptors, the integrity of the inner retinal layers, and the health of the retinal ganglion cells. This test is often used to diagnose and monitor various retinal disorders, such as retinitis pigmentosa, macular degeneration, and diabetic retinopathy.

Retinal pigments refer to the light-sensitive chemicals found in the retina, specifically within the photoreceptor cells called rods and cones. The main types of retinal pigments are rhodopsin (also known as visual purple) in rods and iodopsins in cones. These pigments play a crucial role in the process of vision by absorbing light and initiating a series of chemical reactions that ultimately trigger nerve impulses, which are then transmitted to the brain and interpreted as visual images. Rhodopsin is more sensitive to lower light levels and is responsible for night vision, while iodopsins are sensitive to specific wavelengths of light and contribute to color vision.

Cyclic nucleotide phosphodiesterases (PDEs) are a family of enzymes that play a crucial role in regulating intracellular levels of cyclic nucleotides, which are important second messengers in various cellular signaling pathways. Among the different types of PDEs, type 6 (PDE6) is specifically expressed in the photoreceptor cells of the retina and is involved in the visual signal transduction cascade.

PDE6 is composed of two catalytic subunits, PDE6α and PDE6β, which are arranged in a heterodimeric complex. These subunits have distinct roles in the enzyme's activity: PDE6α contains the catalytic site that hydrolyzes cyclic guanosine monophosphate (cGMP) to GMP, while PDE6β regulates the activity of PDE6α through its inhibitory γ subunit.

In the visual signal transduction pathway, light stimulation leads to the activation of rhodopsin, which triggers a cascade of events that ultimately results in the hydrolysis of cGMP by PDE6. This reduction in cGMP levels causes the closure of cyclic nucleotide-gated channels in the plasma membrane, leading to hyperpolarization of the photoreceptor cells and the transmission of visual signals to the brain.

Defects in PDE6 have been implicated in various retinal disorders, including congenital stationary night blindness, retinitis pigmentosa, and age-related macular degeneration. Therefore, understanding the structure and function of PDE6 is essential for developing novel therapeutic strategies to treat these vision-threatening diseases.

Dark adaptation is the process by which the eyes adjust to low levels of light. This process allows the eyes to become more sensitive to light and see better in the dark. It involves the dilation of the pupils, as well as chemical changes in the rods and cones (photoreceptor cells) of the retina. These changes allow the eye to detect even small amounts of light and improve visual acuity in low-light conditions. Dark adaptation typically takes several minutes to occur fully, but can be faster or slower depending on various factors such as age, prior exposure to light, and certain medical conditions. It is an important process for maintaining good vision in a variety of lighting conditions.

"Ambystoma" is a genus of salamanders, also known as the mole salamanders. These amphibians are characterized by their fossorial (burrowing) habits and typically have four limbs, a tail, and moist skin. They are found primarily in North America, with a few species in Asia and Europe. Some well-known members of this genus include the axolotl (A. mexicanum), which is famous for its ability to regenerate lost body parts, and the spotted salamander (A. maculatum). The name "Ambystoma" comes from the Greek words "amblys," meaning blunt, and "stoma," meaning mouth, in reference to the wide, blunt snout of these animals.

Recoverin is a protein found in the retina of the eye that plays a role in protecting photoreceptor cells from light-induced damage. It is a member of the neuronal calcium sensor family and functions as a calmodulin-binding protein, which means it can bind to calcium ions and regulate various cellular processes.

Recoverin is particularly important for the regulation of visual transduction, the process by which light is converted into electrical signals in the eye. When exposed to light, photoreceptor cells release calcium ions, which then bind to recoverin and cause it to change shape. This shape change allows recoverin to inhibit a key enzyme involved in the visual transduction cascade, helping to prevent excessive signaling and protect the photoreceptor cells from damage.

Mutations in the gene that encodes recoverin have been associated with certain inherited eye diseases, such as congenital stationary night blindness and retinitis pigmentosa. These mutations can disrupt the normal function of recoverin and lead to progressive vision loss.

Retinitis pigmentosa (RP) is a group of rare, genetic disorders that involve a breakdown and loss of cells in the retina - a light-sensitive tissue located at the back of the eye. The retina converts light into electrical signals which are then sent to the brain and interpreted as visual images.

In RP, the cells that detect light (rods and cones) degenerate more slowly than other cells in the retina, leading to a progressive loss of vision. Symptoms typically begin in childhood with night blindness (difficulty seeing in low light), followed by a gradual narrowing of the visual field (tunnel vision). Over time, this can lead to significant vision loss and even blindness.

The condition is usually inherited and there are several different genes that have been associated with RP. The diagnosis is typically made based on a combination of genetic testing, family history, and clinical examination. Currently, there is no cure for RP, but researchers are actively working to develop new treatments that may help slow or stop the progression of the disease.

Light signal transduction is a biological process that refers to the way in which cells convert light signals into chemical or electrical responses. This process typically involves several components, including a light-sensitive receptor (such as a photopigment), a signaling molecule (like a G-protein or calcium ion), and an effector protein that triggers a downstream response.

In the visual system, for example, light enters the eye and activates photoreceptor cells in the retina. These cells contain a light-sensitive pigment called rhodopsin, which undergoes a chemical change when struck by a photon of light. This change triggers a cascade of signaling events that ultimately lead to the transmission of visual information to the brain.

Light signal transduction is also involved in other biological processes, such as the regulation of circadian rhythms and the synthesis of vitamin D. In these cases, specialized cells contain light-sensitive receptors that allow them to detect changes in ambient light levels and adjust their physiology accordingly.

Overall, light signal transduction is a critical mechanism by which organisms are able to sense and respond to their environment.

'Bufo marinus' is the scientific name for a species of toad commonly known as the Cane Toad or Giant Toad. This toad is native to Central and South America, but has been introduced to various parts of the world including Florida, Australia, and several Pacific islands. The toad produces a toxic secretion from glands on its back and neck, which can be harmful or fatal if ingested by pets or humans.

Cyclic guanosine monophosphate (cGMP) is a important second messenger molecule that plays a crucial role in various biological processes within the human body. It is synthesized from guanosine triphosphate (GTP) by the enzyme guanylyl cyclase.

Cyclic GMP is involved in regulating diverse physiological functions, such as smooth muscle relaxation, cardiovascular function, and neurotransmission. It also plays a role in modulating immune responses and cellular growth and differentiation.

In the medical field, changes in cGMP levels or dysregulation of cGMP-dependent pathways have been implicated in various disease states, including pulmonary hypertension, heart failure, erectile dysfunction, and glaucoma. Therefore, pharmacological agents that target cGMP signaling are being developed as potential therapeutic options for these conditions.

Retinal bipolar cells are a type of neuron located in the inner nuclear layer of the retina, an light-sensitive tissue that lines the interior of the eye. These cells play a crucial role in the visual system by transmitting visual signals from photoreceptors (rods and cones) to ganglion cells, which then relay this information to the brain via the optic nerve.

Bipolar cells have two processes or "arms" that connect to either photoreceptors or ganglion cells: one process receives input from photoreceptors and the other transmits output to ganglion cells. They are called "bipolar" because of this dual connection. These cells can be classified into different types based on their morphology, neurotransmitter usage, and synaptic connections with photoreceptors and ganglion cells.

There are two primary types of retinal bipolar cells: rod bipolar cells and cone bipolar cells. Rod bipolar cells mainly transmit signals from rod photoreceptors, which are responsible for low-light vision, while cone bipolar cells connect to cone photoreceptors that handle color vision and high visual acuity in bright light conditions.

Retinal bipolar cells help process and encode visual information based on contrast, spatial patterns, and temporal changes in light intensity. Their output contributes significantly to the formation of visual perceptions such as brightness, contrast, and motion detection. Dysfunction or damage to retinal bipolar cells can lead to various visual impairments and diseases, including some forms of vision loss.

I am not aware of a medical definition for the term "darkness." In general, darkness refers to the absence of light. It is not a term that is commonly used in the medical field, and it does not have a specific clinical meaning. If you have a question about a specific medical term or concept, I would be happy to try to help you understand it.

Cyclic nucleotide-gated (CNG) channels are a type of ion channel found in the membranes of certain cells, particularly in the sensory neurons of the visual and olfactory systems. They are called cyclic nucleotide-gated because they can be activated or regulated by the binding of cyclic nucleotides, such as cyclic adenosine monophosphate (cAMP) or cyclic guanosine monophosphate (cGMP), to the intracellular domain of the channel.

CNG channels are permeable to cations, including sodium (Na+) and calcium (Ca2+) ions, and their activation allows these ions to flow into the cell. This influx of cations can trigger a variety of cellular responses, such as the initiation of visual or olfactory signaling pathways.

CNG channels are composed of four subunits that form a functional channel. Each subunit has a cyclic nucleotide-binding domain (CNBD) in its intracellular region, which can bind to cyclic nucleotides and regulate the opening and closing of the channel. The CNBD is connected to the pore-forming region of the channel by a flexible linker, allowing for conformational changes in the CNBD to be transmitted to the pore and modulate ion conductance.

CNG channels play important roles in various physiological processes, including sensory perception, neurotransmission, and cellular signaling. Dysfunction of CNG channels has been implicated in several human diseases, such as retinitis pigmentosa, congenital stationary night blindness, and cystic fibrosis.

The photoreceptors (rods and cones) transmit to the bipolar cells, which transmit then to the retinal ganglion cells. Retinal ... rods, cones, and intrinsically photosensitive retinal ganglion cells. The two classic photoreceptor cells are rods and cones, ... The membranous photoreceptor protein opsin contains a pigment molecule called retinal. In rod cells, these together are called ... Intrinsically photosensitive retinal ganglion cells (ipRGCs) are a subset (≈1-3%) of retinal ganglion cells, unlike other ...
The human eye contains three types of photoreceptors, rods, cones, and intrinsically photosensitive retinal ganglion cells ( ... Cone cells are able to regain maximum retinal sensitivity in 9-10 minutes of darkness whereas rods require 30-45 minutes to do ... The photopigment rhodopsin found in human rod cells is composed of retinal, a form of vitamin A, bound to an opsin protein. ... In humans, rod cells are exclusively responsible for night vision as cone cells are only able to function at higher ...
"Responses of retinal rods to single photons", 819 citations 1989 "Cyclic GMP-activated conductance of retinal photoreceptor ... Yau KW, Baylor DA (1989). "Cyclic GMP-activated conductance of retinal photoreceptor cells". Annual Review of Neuroscience. 12 ... Baylor DA, Lamb TD, Yau KW (1979). "Responses of retinal rods to single photons". Journal of Physiology. 288: 613-634. doi: ... Hattar, S; Liao HW; Takao M; Berson DM; Yau KW (2002). "Melanopsin-containing retinal ganglion cells: architecture, projections ...
... the retinal rod photoreceptor cells begin degenerating at about postnatal day 10, and by 3 weeks no rod photoreceptors remain. ... Bennett J, Tanabe T, Sun D, Zeng Y, Kjeldbye H, Gouras P, Maguire AM (Jun 1996). "Photoreceptor cell rescue in retinal ... There are two types of photoreceptors: cones and rods. The rod and cone PDE6 complexes have different structures. PDE6β ... "The human beta-subunit of rod photoreceptor cGMP phosphodiesterase: complete retinal cDNA sequence and evidence for expression ...
May 2020). "SARM1 deficiency promotes rod and cone photoreceptor cell survival in a model of retinal degeneration". Life ... October 2020). "SARM1 depletion rescues NMNAT1-dependent photoreceptor cell death and retinal degeneration". eLife. 9: e62027. ... January 2022). "SARM1 Ablation Is Protective and Preserves Spatial Vision in an In Vivo Mouse Model of Retinal Ganglion Cell ... 2022). "SARM1 Promotes Photoreceptor Degeneration in an Oxidative Stress Model of Retinal Degeneration". Frontiers in ...
Provencio concluded that either melanopsin-containing retinal ganglion cells or outer-retinal photoreceptors (rods and cones) ... He found that blind mice without classical photoreceptor cells (rods and cones) still had eye-mediated responses to light. Mice ... Since retinal ganglion cells that express melanopsin have also been found in humans, these studies suggest that blind humans ... cones and/or melanopsin cells, was missing in the mice lacking melanopsin cells. Therefore, Provencio suggested that cells ...
They are found in the photoreceptor cells in the retina of eye. The opsin in the vertebrate rod cells is rhodopsin. The rods ... and 6 occur in rod cell outer segments; Steps 1, 2, and 7 occur in retinal pigment epithelium (RPE) cells. RPE65 ... It regenerates 11-cis-retinal. For example, the visual cycle of mammalian rod cells is as follows: all-trans-retinyl ester + ... Retinal is a conjugated chromophore. In the human eye, retinal begins in an 11-cis-retinal configuration, which - upon ...
Nasonkin I, Illing M, Koehler MR, Schmid M, Molday RS, Weber BH (January 1998). "Mapping of the rod photoreceptor ABC ... Sun H, Nathans J (September 1997). "Stargardt's ABCR is localized to the disc membrane of retinal rod outer segments". Nature ... Allikmets R (September 1997). "A photoreceptor cell-specific ATP-binding transporter gene (ABCR) is mutated in recessive ... Nasonkin I, Illing M, Koehler MR, Schmid M, Molday RS, Weber BH (January 1998). "Mapping of the rod photoreceptor ABC ...
... including the photoreceptors (rods and cones), inner retinal cells (bipolar and amacrine cells), and the ganglion cells. ... while the remainder of the wave is produced by a mixture of cells including photoreceptors, bipolar, amacrine, and Müller cells ... The pattern ERG (PERG), evoked by an alternating checkerboard stimulus, primarily reflects activity of retinal ganglion cells. ... may be useful in assessing retinal ganglion cell function in diseases like glaucoma. The multifocal ERG is used to record ...
Without 11-cis-retinal, the rod photoreceptor cells no longer produce all-trans-retinol and production of A2E is halted. The ... The formation of A2E is largely associated with the rod photoreceptor cells. These cells account for approximately 95% of human ... The all-trans-retinal is released from opsin, reduced to all-trans-retinol, then transported from the photoreceptor cells back ... The 11-cis-retinol is oxidized to 11-cis retinal and transported to photoreceptor cells where it binds to opsin to form ...
AII amacrine cell serve the critical role of transferring light signals from rod photoreceptors to the retinal ganglion cells ( ... The rod photoreceptor synapses with the rod bipolar cell. This rod bipolar cell will directly (exclusively) synapse with an AII ... Note: A small proportion of rods contact the cone bipolar cells directly. There is only one type of rod bipolar cell: an ON- ... cone bipolar cells in turn contact the ON- and OFF-centre retinal ganglion cells, respectively. ...
... including the photoreceptors (rods and cones), inner retinal cells (bipolar and amacrine cells), and the ganglion cells. ... Vitreo-retinal surgery, deals with surgical management of retinal and posterior segment diseases Medical retina and vitreo- ... In 1949, he performed the first successful treatment of a retinal detachment with a light beam (light coagulation) with a self- ... Electrooculography (EOG) is a technique for measuring the corneo-retinal standing potential that exists between the front and ...
... rod precursors proliferate and differentiate into new rod photoreceptors. This population of progenitor cells can be induced to ... Montgomery, JE; Parsons, MJ; Hyde, DR (2010). "A novel model of retinal ablation demonstrates that the extent of rod cell death ... Retinal regeneration refers to the restoration of vision in vertebrates that have suffered retinal lesions or retinal ... which dedifferentiate into stem-like cells and proliferate into neural progenitor cells in response to retinal damage. While ...
The synaptic contacts amongst photoreceptor cells, bipolar cells, and horizontal cells were preserved in the ursodoxicoltaurine ... yet non-altered retinal morphology or function. Even at P30, a stage where rod and cone function is usually greatly diminished ... This caused a considerable preservation in cone cell amount and function at P50, and a modest rod cell amount at P30. In the ... Electroretinography (ERG), photoreceptor cell counts, cone photoreceptor nuclei counts, and TUNEL labeling were all analyzed to ...
Eventually, loss of rod cells leads to loss of cone cells (cone photoreceptors), the mainstay of human vision. Symptoms of RP ... Photoreceptor cell death is the eventual outcome of retinal degeneration. Without proper function of the photoreceptor cells, ... RP begins with death of rod photoreceptor cells, which are the only cells in the retina to express rhodopsin and which express ... Rhodopsin is the opsin of rod photoreceptor cells, which are the only cells in the retina that express rhodopsin and which ...
"Mutations in the cone-rod homeobox gene are associated with the cone-rod dystrophy photoreceptor degeneration". Neuron. 19 (6 ... by this gene is a photoreceptor-specific transcription factor which plays a role in the differentiation of photoreceptor cells ... "Genetic linkage of cone-rod retinal dystrophy to chromosome 19q and evidence for segregation distortion". Nature Genetics. 6 (2 ... "Cone-rod dystrophy due to mutations in a novel photoreceptor-specific homeobox gene (CRX) essential for maintenance of the ...
... is expressed in the retinal pigment epithelium (RPE, a layer of epithelial cells that nourish the photoreceptor cells) ... It is also found in rods and cones. The photoisomerization of 11-cis-retinal to all-trans-retinal initiates the ... 11-cis-retinol is then used in visual pigment regeneration in photoreceptor cells. RPE65 belongs to the carotenoid oxygenase ... Cell. 122 (3): 449-59. doi:10.1016/j.cell.2005.06.042. PMC 2748856. PMID 16096063. Ma J, Zhang J, Othersen KL, Moiseyev G, ...
He developed a widely-used method for observing the electrical activity of single rod and cone photoreceptor cells and ... Baylor, D A; Lamb, T D; Yau, K W (March 1979). "Responses of retinal rods to single photons". The Journal of Physiology. 288: ... in particular the mechanism in which light energy is converted to neural signals within the rod and cone photoreceptor cells of ... method for recording the electrical currents of individual cells he recorded for the first time the response of retinal rods to ...
... retina by influencing the structure and function of both the rod photoreceptor cells and supporting cells called the retinal ... a degeneration of the retinal cells. Usually, the rod cells of the retina are affected first, leading to early night blindness ... The photoreceptor cells usually start to degenerate from the outer periphery to the center of the retina, including the macula ... In other cases, early degeneration of the cone cells in the macula occurs, leading to a loss of central acuity. In some cases, ...
The progenitor cell can then divide and differentiate into a number of retinal cell types, including photoreceptor cells, that ... "Adult Human Müller Glia Cells Are a Highly Efficient Source of Rod Photoreceptors". Stem Cells. 29 (2): 344-56. doi:10.1002/ ... The Müller glia cell is the only retinal glial cell that shares a common cell lineage with retinal neurons. A subset of Müller ... Damage to retinal cells induces Müller cells to produce gliosis. The result of the response varies depending on the damage and ...
With about 4.6 million cone cells and 92 million rod cells, or 96.6 million photoreceptors per retina, on average each retinal ... there are at least five main classes of retinal ganglion cells: Midget cell (parvocellular, or P pathway; P cells) Parasol cell ... These cells are known as midget retinal ganglion cells, based on the small sizes of their dendritic trees and cell bodies. ... These cells are known as parasol retinal ganglion cells, based on the large sizes of their dendritic trees and cell bodies. ...
... including retinal ganglion cells, amacrine cells, bipolar cells, horizontal cells, rod photoreceptors, cone photoreceptors, and ... Ath5 expression in retinal progenitor cells biases their differentiation into a retinal ganglion cell fate. An example of an ... Retinal precursor cells are biological cells that differentiate into the various cell types of the retina during development. ... retinal cells originate from the anterior portion of the neural plate termed the eye field. Eye field cells with a retinal fate ...
Bipolar cell of the retina Horizontal cell Photoreceptor cell Retinal ganglion cell Kolb, H; Nelson, R; Fernandez, E (1995). " ... amacrine cells work laterally, but whereas horizontal cells are connected to the output of rod and cone cells, amacrine cells ... Amacrine cells operate at inner plexiform layer (IPL), the second synaptic retinal layer where bipolar cells and retinal ... but some specific functions of the retinal amacrine cells can be outlined. Intercept retinal ganglion cells and/ or bipolar ...
Rod cells are photoreceptor cells in the retina of the eye that can function in lower light better than the other type of ... Thus, rods can have a large response to a small amount of light. As the retinal component of rhodopsin is derived from vitamin ... Rods are much more common than cones, with about 120 million rod cells compared to 6 to 7 million cone cells. Like cones, rod ... A human rod cell is about 2 microns in diameter and 100 microns long. Rods are not all morphologically the same; in mice, rods ...
Rod cell-specific antigens in retinoblastoma. Arch Ophthalmol 1989;107:1061-63 Kivela T. Glycoconjugates in retinoblastoma: a ... that the tumor cells forming the Flexner-Wintersteiner rosette have ultrastructural features of primitive photoreceptor cells. ... suggesting that Flexner-Wintersteiner rosettes represent a specific form of retinal differentiation. In addition to being a ... dendritic cell neurofibroma, astroblastoma, large cell neuroendocrine tumor of cervix, clear cell ependymoma of spinal cord, ...
In general, PRAs are characterised by initial loss of rod photoreceptor cell function followed by that of the cones and for ... Characterized by dysplasia of the rod cell unit and subsequent degeneration of the cone cell unit. Rod cell response is nearly ... This is a disease with normal rod and cone cell development but late onset degeneration of the rod cells that progresses to the ... Irish Setter - Rod cell response is nearly absent. Night blindness by six to eight weeks old, often blind by one year old. ...
There are photoreceptor cells in the retina called rods and cones, which transduce light energy into nerve signals that can be ... retinal vein occlusion (a blockage of a retinal vein), anemia, leukemia or diabetes. At the early stage, a retinal hemorrhage ... Retinal hemorrhage (UK English: retinal haemorrhage) is a disorder of the eye in which bleeding occurs in the retina, the light ... Pilyugina S. "Retinal Physician - Ocular Dietary Supplementation - Food For Thought". Retinal Physician. Retrieved 2018-09-13. ...
The rod cells are the photoreceptor cells in the retina capable of sensing light. However, they are not what sets the ... The photosensitive retinal ganglion cells contain a pigment called melanopsin. This photopigment is depolarized in the presence ... Also, pharmacological manipulation, cell culture imaging and computational biology all make attempts at doing this but in the ... The neuroscience of rhythm refers to the various forms of rhythm generated by the central nervous system (CNS). Nerve cells, ...
... play essential and synergistic roles in affecting photosensitivity and outer segment morphogenesis of rod photoreceptor cells. ... Initially named "ORP1" for its response to in vivo retinal oxygen levels (designated ORP1 for 'oxygen-regulated protein-1'), ... The encoded protein is a protein associated with the photoreceptor cell microtubules in the retina and is necessary for the ... 1999). "Mutations in a gene encoding a new oxygen-regulated photoreceptor protein cause dominant retinitis pigmentosa". Nat. ...
... the photoreceptors synapse directly onto bipolar cells, which in turn synapse onto ganglion cells of the outermost layer, which ... The retina adapts to change in light through the use of the rods. In the dark, the chromophore retinal has a bent shape called ... resulting in hyper-polarization of the photoreceptor. Rods and cones differ in function. Rods are found primarily in the ... About 130 million photo-receptors absorb light, yet roughly 1.2 million axons of ganglion cells transmit information from the ...
Therefore, they constitute a third class of photoreceptors, in addition to rod and cone cells. Compared to the rods and cones, ... Unlike the visual opsins in rod cells and cone cells, which rely on the standard visual cycles for recharging all-trans-retinal ... Bistratified cell Melanopsin Midget cell Parasol cell Photoreceptor Keeler, Clyde E. (1927). "Iris movements in blind mice". ... Intrinsically photosensitive retinal ganglion cells (ipRGCs), also called photosensitive retinal ganglion cells (pRGC), or ...
Cell adhesion molecules are known to play a pivotal … ... Retinal Cone Photoreceptor Cells * Retinal Rod Photoreceptor ... Neurofascin Is a Novel Component of Rod Photoreceptor Synapses in the Outer Retina Front Neural Circuits. 2021 Feb 10:15:635849 ... Consistent with these findings, we also observe a decrease in rod-driven retinal responses with disruption of Nfasc function ... Cell adhesion molecules are known to play a pivotal role in assembling neural circuits. They serve as recognition molecules ...
Photoreceptors rely on distinct membrane compartments to support their specialized function. Unlike protein localization, ... Retinal Rod Photoreceptor Cells / metabolism* * Retinal Rod Photoreceptor Cells / ultrastructure * Rhodopsin / metabolism ... Nano-scale resolution of native retinal rod disk membranes reveals differences in lipid composition J Cell Biol. 2021 Aug 2;220 ... Photoreceptors rely on distinct membrane compartments to support their specialized function. Unlike protein localization, ...
The photoreceptors (rods and cones) transmit to the bipolar cells, which transmit then to the retinal ganglion cells. Retinal ... rods, cones, and intrinsically photosensitive retinal ganglion cells. The two classic photoreceptor cells are rods and cones, ... The membranous photoreceptor protein opsin contains a pigment molecule called retinal. In rod cells, these together are called ... Intrinsically photosensitive retinal ganglion cells (ipRGCs) are a subset (≈1-3%) of retinal ganglion cells, unlike other ...
The ophthalmic preparations may be supplemented with oral intake of various retinal photoreceptors vision supporting lutein, ... Night blindness and decreased night vision is associated with retinal diseases such as dry age related macular degeneration, ... bipolar cells. 710, 712 situated between photoreceptors (. rods. 706 and cones 705) and ganglion cells. 714. The therapeutic ... 210000000964 Retinal Cone Photoreceptor Cells Anatomy 0.000 description 2 * 210000003994 Retinal Ganglion Cells Anatomy 0.000 ...
Light that enters the eye activates rod and cone photoreceptors, which then activates retinal ganglion cells. A signal travels ... known as bipolar cells. In a healthy eye, bipolar cells receive signals from photoreceptor cells across a synapse and then ... Zack, Gamm, and their teams plan to study precursor photoreceptor cells derived from human stem cells to determine what factors ... retinal damage induces Muller glia to reprogram and re-enter the cell cycle to produce neuronal progenitor cells, which are ...
Elisa Cuevas: Retinal organoids lacking NRL are rich in blue cone cells at expense of rod photoreceptors ... NRL−/− gene edited human embryonic stem cells generate rod‐deficient retinal organoids enriched in S‐cone‐like photoreceptors ( ... Single-Cell RNA-Seq Analysis of Retinal Development Identifies NFI Factors as Regulating Mitotic Exit and Late-Born Cell ... Generation of Retinal Pigment Epithelial Cells Derived from Human Embryonic Stem Cells Lacking Human Leukocyte Antigen Class I ...
... at NEI develops novel therapies for retinal and macular degeneration. Learn more about the lab and its research. ... The Retinal Development, Genetics and Therapy Section in the Neurobiology Neurodegeneration & Repair Laboratory (NNRL) ... Accelerated Development of Rod Photoreceptors in Retinal Organoids Derived from Human Pluripotent Stem Cells by Supplementation ... Cell Rep. 2016;17(9):2460-2473. PMID:27880916.. Recruitment of Rod Photoreceptors from Short-Wavelength-Sensitive Cones during ...
Retinal disintegration includes the damage of rods and photoreceptor cells, which are located in the retina. As a result, ones ... Over time, the sensitivity of these cells declines, and it becomes difficult to distinguish colours. Blue is the colour that ... The retina contains colour sensitive cells, which help one to perceive and differentiate colours. ...
Retinal Bipolar Cells. Cyclic Nucleotide-Gated Cation Channels. Retinal Rod Photoreceptor Cells. Photoreceptor Cells, ... As rods degenerate, synaptic structures between rod and rod bipolar cells disappear and the rod bipolar cells extend their ... a surprising degree of plasticity following rescue of rod photoreceptors. The wayward dendrites of rod bipolar cells re- ... Activation of Rod Input in a Model of Retinal Degeneration Reverses Retinal Remodeling and Induces Formation of Functional ...
... an early onset rod/cone retinal cell developmental dysplasia (a dominant trait, much lower in incidence, associated with the ... These include a late onset photoreceptor cell degeneration that typically occurs at 3-5 years of age (a recessive trait ... PRA is caused when the cells at the back of the eye degenerate and lose their function. Some signs to look for are dilated ... The cat liver, however, is poor at metabolizing fat, causing a buildup of fat in the cells of the liver, leading to fatty liver ...
... mice to blue light not only induces cone cell death but also disrupts the inner blood-retinal barrier. Macular edema in humans ... This was accompanied by retinal swelling and the appearance of cystoid spaces in both inner and ONLs of R91W;Nrl−/− mice ... Recently, we generated R91W;Nrl−/− double-mutant mice, which display a well-ordered all-cone retina with normal retinal ... mice led to additional cell death detected within the inner nuclear layer. Microglia/macrophage infiltration at the site of ...
The team examined three forms of retinal degenerative diseases, rod cone dysplasia 1 being the most severe, or earliest onset, ... the time before the peak level of photoreceptor cell death; the "execution phase," when the highest rates of photoreceptor cell ... "We were focusing on what would happen with the photoreceptor cells, the cells that we knew were dying," Beltran said. "But what ... All of these diseases involve the death of photoreceptor cells and each is caused by a distinct genetic mutation. But what ...
Retinal Rod Photoreceptor Cells Medicine & Life Sciences 15% * Computer Simulation Medicine & Life Sciences 10% ... Comprehensive analysis of photoreceptor gene expression and the identification of candidate retinal disease genes. In: Cell. ... Comprehensive analysis of photoreceptor gene expression and the identification of candidate retinal disease genes. Cell. 2001 ... Nearly half of all cloned human retinal disease genes are selectively expressed in rod photoreceptors. In silico mapping of the ...
"Even after retinal diseases kill rod and cone photoreceptors - the cells of the retina that take in light - other retinal cells ... "These non-photoreceptor cells remain physiologically capable of processing electrical and chemical signals, as in the normal ... will support development and testing of the device in nerve cell preparations including isolated cells obtained from rat ... Engineered molecular device may restore vision lost to retinal diseases. Home/Ophthalmology & Visual Sciences/Ophthalmology ...
1991) Polarized sorting of rhodopsin on post-Golgi membranes in frog retinal photoreceptor cells. J Cell Biol 113:1281-1293, ... 2002) Deletional analysis of the rod photoreceptor cell peripherin/RDS carboxy-terminal region. Exp Eye Res 75:143-154, doi: ... 2012) Live-cell imaging evidence for the ciliary transport of rod photoreceptor opsin by heterotrimeric kinesin-2. J Neurosci ... 2006) Retention of function without normal disc morphogenesis occurs in cone but not rod photoreceptors. J Cell Biol 173:59-68 ...
Hsu Y-T, Molday RS (1993) Modulation of the cGMP-gated channel of rod photoreceptor cells by calmodulin. Nature 361: 76-79. ... Yau K-W, Baylor DA (1989) Cyclic GMP-activated conductance of retinal photoreceptor cells. Annu Rev Neurosci 12: 289-327. ... Bönigk W, Altenhofen W, Müller F, Dose A, Illing M, Molday RS, Kaupp UB (1993) Rod and cone photoreceptor cells express ... Similar effects on the Ca2+ affinity have been described for CNGB1a and CNGB1b, the B subunits of CNG channels in retinal rods ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
Rod Outer Segments. Rod Cell Outer Segment. Rods (Retina). Retinal Rod Photoreceptor Cells. ... Retinal Cone Photoreceptor Cells. Photoreceptors. Photoreceptor Cells. Photoreceptors, Invertebrate. Photoreceptor Cells, ... Granuloma, Plasma Cell, Pulmonary. Plasma Cell Granuloma, Pulmonary. C11 - Eye Diseases. Granuloma, Plasma Cell, Orbital. ... G04 - Cell Physiological Phenomena. Cell Physiology. Cell Physiological Phenomena. G05 - Genetic Phenomena. Trans-Activation ( ...
... are a subset of retinal ganglion cells that respond to light independently from rod and cone photoreceptor input. ipRGCs are ... Kumar : Differentiation of Retinal Ganglion Cell Subtypes from Human Induced Pluripotent Stem Cells. Submission. ... Kumar : Differentiation of Retinal Ganglion Cell Subtypes from Human Induced Pluripotent Stem Cells. ... Kumar : Differentiation of Retinal Ganglion Cell Subtypes from Human Induced Pluripotent Stem Cells ...
Retinal Rod Photoreceptor Cells Medicine & Life Sciences 75% * Synapses Medicine & Life Sciences 60% ... ROCK inhibition reduces morphological and functional damage to rod synapses after retinal injury. Halász, É., Zarbin, M. A., ... Injury to Cone Synapses by Retinal Detachment: Differences from Rod Synapses and Protection by ROCK Inhibition. Townes-Anderson ... Coming of age for the photoreceptor synapse. Townes-Anderson, E., Halasz, E., Wang, W. & Zarbin, M., Sep 2021, In: ...
  • In this study, we identified a new player in assembling neural circuits in the outer retina, the L1-family cell adhesion molecule Neurofascin (Nfasc). (nih.gov)
  • Taken together, our data suggest a new role of Nfasc in rod synapses within the mouse outer retina. (nih.gov)
  • The distribution of photoreceptor cells across the surface of the retina has important consequences for vision. (wikipedia.org)
  • Cone photoreceptors are concentrated in a depression in the center of the retina known as the fovea centralis and decrease in number towards the periphery of the retina. (wikipedia.org)
  • Conversely, rod photoreceptors are present at high density throughout the most of the retina with a sharp decline in the fovea. (wikipedia.org)
  • The tapetum lucidum is a reflective structure that is responsible for this superior night vision as it mirrors light back through the retina exposing the photoreceptor cells to an increased amount of light. (wikipedia.org)
  • Goldberg and colleagues have demonstrated through a series of interventions in mice with optic nerve injury that they can successfully regenerate retinal ganglion cells axons, which form the optic nerve that transmits visual information from the retina to the brain. (nih.gov)
  • They expect their studies to identify a list of small molecules and candidate genes that contribute to the ability of photoreceptor cells to home in on their appropriate target cells in the retina, known as bipolar cells. (nih.gov)
  • Our research seeks to answer both basic and translational questions related to the retina and especially focuses on photoreceptors which initiate the visual process. (nih.gov)
  • How are specific cell numbers and their organization with the retina determined? (nih.gov)
  • Our investigations utilize in vivo mouse retina and human retinal organoids derived from pluripotent stem cells as study systems. (nih.gov)
  • The retina contains colour sensitive cells, which help one to perceive and differentiate colours. (infonettc.org)
  • Retinal disintegration includes the damage of rods and photoreceptor cells, which are located in the retina. (infonettc.org)
  • Activation of Rod Input in a Model of Retinal Degeneration Reverses Retinal Remodeling and Induces Formation of Functional Synapses and Recovery of Visual Signaling in the Adult Retina. (duke.edu)
  • Moreover, we show that the adult mouse retina displays a surprising degree of plasticity upon activation of rod input. (duke.edu)
  • We show that the adult mammalian neural retina exhibits a surprising degree of plasticity following rescue of rod photoreceptors. (duke.edu)
  • Recently, we generated R91W;Nrl −/− double-mutant mice, which display a well-ordered all-cone retina with normal retinal vasculature and a strong photopic function that generates useful vision. (nature.com)
  • An additional surprise was that the differentially expressed proteins were present not only in photoreceptor cells but also in other cells in the retina, including horizontal and Müller cells. (mvrf.org)
  • To identify the full set of genes expressed by mammalian rods, we conducted serial analysis of gene expression (SAGE) by using libraries generated from mature and developing mouse retina. (johnshopkins.edu)
  • Even after retinal diseases kill rod and cone photoreceptors - the cells of the retina that take in light - other retinal cells often remain healthy," said Dr. Pepperberg, the Searls-Schenk Professor of Ophthalmology at the UIC College of Medicine and principal investigator on the project. (uic.edu)
  • These non-photoreceptor cells remain physiologically capable of processing electrical and chemical signals, as in the normal retina, but in the absence of functioning rods and cones, they lack light-responsive input signals," Dr. Pepperberg said. (uic.edu)
  • Results: Here, cell type-specific transgenic lines were generated to enable TRAP studies for retinal ganglion cells and rod photoreceptors in the Xenopus laevis retina. (johnshopkins.edu)
  • There are about 100-120 million rods and 7-8 million cones in the retina [Wan 95, Fer 01]. (informit.com)
  • The region of the retina with the highest density of photoreceptors is called the fovea . (informit.com)
  • These disorders typically begin in mid-adulthood and are characterized by an abnormal buildup of pigment in cells underlying the retina. (medlineplus.gov)
  • The various areas that he examines in his Retina study include Endocrinology, Postsynaptic potential, Retinal, Neurotransmission and Synapse. (research.com)
  • Functional architecture of synapses in the inner retina: segregation of visual signals by stratification of bipolar cell axon terminals. (research.com)
  • His work carried out in the field of Retina brings together such families of science as Receptive field, Neurotransmission and Cell biology. (research.com)
  • His main research concerns Retina, Retinal ganglion, Cell biology, Retinal ganglion cell and Ophthalmology. (research.com)
  • The study incorporates disciplines such as gamma-Aminobutyric acid, Biophysics, Retinal and Anatomy in addition to Retina. (research.com)
  • The various areas that Samuel M. Wu examines in his Cell biology study include Vertebrate retina, TFEB and Immunology. (research.com)
  • Samuel M. Wu spends much of his time researching Cell biology, Retina, Intraocular pressure, Retinal degeneration and Ophthalmology. (research.com)
  • His work in Retina covers topics such as Anatomy which are related to areas like Retinal. (research.com)
  • The distribution of rods and cones across the surface of the retina also has important consequences for vision ( Figure 11.10 ). (nih.gov)
  • Despite the fact that perception in typical daytime light levels is dominated by cone-mediated vision, the total number of rods in the human retina (91 million) far exceeds the number of cones (roughly 4.5 million). (nih.gov)
  • As a result, the density of rods is much greater than cones throughout most of the retina. (nih.gov)
  • Distribution of rods and cones in the human retina. (nih.gov)
  • It is easier to see a dim object (such as a faint star) by looking away from it, so that the stimulus falls on the region of the retina that is richest in rods (see Figure 11.10 ). (nih.gov)
  • Another anatomical feature of the fovea (which literally means "pit") that contributes to the superior acuity of the cone system is that the layers of cell bodies and processes that overlie the photoreceptors in other areas of the retina are displaced around the fovea, and especially the foveola (see Figure 11.11 ). (nih.gov)
  • Between embryonic day 12 and postnatal day 21, six major neuronal and one glia cell type are generated from multipotential progenitors in a characteristic sequence during mouse retina development. (biomedcentral.com)
  • Revealing the intrinsic program of gene regulation that accompanies mammalian retinal development is a key step for eventual cure of many human retina diseases and blindness. (biomedcentral.com)
  • Given the high rate of rod birth in newborn mice and the fact that rods constitute more than 70% of the cells in the adult mouse retina, the majority of cells that are electroporated at P0 are rods. (wustl.edu)
  • Rod photoreceptors and rod-connected nerve cells through the retina are responsible for pathways concerned with night vision and increased sensitivity of our visual system under what is called scotopic conditions (conditions of very little ambient light). (utah.edu)
  • When looking at the mosaic of human photoreceptors it becomes apparent that the human retina is actually rod-dominated numerically (Fig. 1). (utah.edu)
  • Both Golgi impregnation of single rod bipolar cells (Fig. 6) and immunocytochemical staining of rod bipolar cell populations with protein kinase C (PKC) (Fig. 7) show the characteristic morphology of the rod bipolar cell type in mammalian retina (Kolb et al. (utah.edu)
  • Two amacrine cells are key in the rod pathway circuitry through the mammalian retina (Fig. 10). (utah.edu)
  • Our results demonstrate for the first time a melanopsin-dependent regulation of visual processing within the retina, revealing an important function for inner retinal photoreceptors in optimizing classical visual pathways according to time of day. (ox.ac.uk)
  • Figures 323 & 324 from Chapter 13 (Cilia and Flagella) of 'The Cell' by Don W. Fawcett M.D. The outer segments of the rods and cones of the vertebrate retina and many photoreceptors of invertebrates b. (cellimagelibrary.org)
  • TEM image of epon section of a freeze-substituted mouse retina illustrating the unusual distribution of heterochromatin in rod receptor nuclei where the compact heterochromatin is centrally located. (cellimagelibrary.org)
  • The key photoreceptors, known as the rod cells and cone cells, and downstream neurons lie within the retina. (medcell.org)
  • injection of purmorphamine promoted the activation of Mller glial cells, and in turn, the production of rod-like photoreceptors in acute damaged retina. (exposed-skin-care.net)
  • Our goals were twofold: 1) to characterize the gene expression, protein expression, and activity of key synthesizing and regulating enzymes of energy metabolism in the whole mouse retina, retinal compartments, and/or cells and 2) to provide an integrative analysis of the results related to function. (molvis.org)
  • Expression of nucleoside diphosphate kinase, mitochondria-associated adenylate kinase, and several mitochondria-associated creatine kinase isozymes was highest in the outer retina, whereas expression of cytosolic adenylate kinase and brain creatine kinase was higher in the cones, horizontal cells, and amacrine cells indicating the diversity of ATP-buffering strategies among retinal neurons. (molvis.org)
  • Retinal nerve fibers exit the eye through the optic nerve, located nasally and on the same plane as the anatomical center of the retina. (medscape.com)
  • The outermost layer of the retina, the retinal pigment epithelium, is tightly attached to the choroid. (medscape.com)
  • Assuming that the ocular media (cornea, anterior chamber, lens, and vitreous) are not cloudy, the living retina can be examined using a direct or indirect ophthalmoscope or a retinal lens at the slit lamp. (medscape.com)
  • In addition, the retina may be photographed using a retinal camera. (medscape.com)
  • The retina, with the exception of the blood vessels coursing through it, is transparent to the examiner up to its outer layer, the retinal pigment epithelium. (medscape.com)
  • The examiner sees the neurosensory retina against the background orange color of the melanin containing retinal pigment epithelium and blood-filled choroidal layer of the eye. (medscape.com)
  • There is a potential space between the neurosensory retina and the retinal pigment epithelium. (medscape.com)
  • In a retinal detachment, this space fills with fluid and detaches the neurosensory retina from the underlying retinal pigment epithelium. (medscape.com)
  • The central area of the retina, called the macula , contains a high density of color-sensitive photoreceptor (light-sensing) cells. (msdmanuals.com)
  • The peripheral area of the retina, which surrounds the macula, contains photoreceptor cells called rods , which respond to lower light levels but are not color sensitive. (msdmanuals.com)
  • The central retinal artery (the other major source of blood to the retina) reaches the retina near the optic nerve and then branches out within the retina. (msdmanuals.com)
  • Blood drains from the retina into branches of the central retinal vein . (msdmanuals.com)
  • Many common eye diseases, including age-related macular degeneration, glaucoma and diabetic retinopathy, put these cells at risk. (nih.gov)
  • Dr. Bo Chen's research focuses on mechanistic and therapeutic studies of retinal degenerative diseases caused by loss of photoreceptors or retinal ganglion cells, such as age-related macular degeneration, retinitis pigmentosa, and glaucoma. (nih.gov)
  • Dysfunction or loss of photoreceptors is the primary cause of vision impairment in almost all cases of retinal and macular degeneration. (nih.gov)
  • Retinas from these mice undergo stereotypic retinal remodeling as a consequence of rod malfunction and degeneration. (duke.edu)
  • These findings demonstrate remarkable plasticity extending beyond the developmental period and support efforts to repair or replace defective rods in patients blinded by rod degeneration. (duke.edu)
  • The acute model of light-induced retinal degeneration uses short exposure to bright white light to study photoreceptor cell death leading to loss of vision. (nature.com)
  • The team examined three forms of retinal degenerative diseases, rod cone dysplasia 1 being the most severe, or earliest onset, followed by X-linked progressive retinal atrophy 2 and then early retinal degeneration. (mvrf.org)
  • According to Dr. Pepperberg, success in this early work and in future studies that test the technology in animal experiments could lead to a new type of molecular therapy for macular degeneration and related photoreceptor degenerative diseases. (uic.edu)
  • This disk membrane deficiency is one of the most severe among the retinal degeneration models and is comparable to rhodopsin knock-out mice that are also incapable of forming disks. (jneurosci.org)
  • Like other retinal disorders caused by PRPH2 gene mutations, retinitis pigmentosa involves a slow degeneration of photoreceptor cells, leading to progressive vision loss. (medlineplus.gov)
  • Growing evidence suggests a role for lysosome-related mechanisms in retinal degeneration. (irrf.org)
  • Oxidative stress plays a key role in driving pathological events in several different ocular diseases, which lead to retinal degeneration and ultimately blindness. (mdpi.com)
  • The disease leads to degeneration of retinal photoreceptor cells in dog. (genocan.eu)
  • Mutations in the PRPH2 gene cause a variety of retinal disorders, including a group of disorders called pattern dystrophies of the retinal pigment epithelium. (medlineplus.gov)
  • For example, researchers have reported a family with retinitis pigmentosa (described above), pattern dystrophy of the retinal pigment epithelium, and retinitis punctata albescens (an eye disorder similar to retinitis pigmentosa) in different individuals with the same PRPH2 mutation. (medlineplus.gov)
  • A purplish-red, light-sensitive pigment found in RETINAL ROD CELLS of most vertebrates. (lookformedical.com)
  • Retinitis pigmentosa is characterized by retinal pigment deposits visible on fundus examination and primary loss of rod photoreceptor cells followed by secondary loss of cone photoreceptors. (nih.gov)
  • Genome editing was previously used to restore vision in mice with the genetic eye disease Leber congenital amaurosis, which affects the retinal pigment epithelium, a layer of non-neuronal cells in the eye that supports the light-sensing rod and cone photoreceptor cells. (scienceboard.net)
  • Clinical evidence for neovascularization includes retinal pigment epithelium (RPE) elevation, subretinal hemorrhage, and/or the presence of exudate. (medscape.com)
  • The atrophic retinal pigment epithelium (RPE) demonstrates staining of the underlying choroidal vasculature. (medscape.com)
  • The atrophic areas are easily distinguished by the hyperfluorescence of the retinal pigment epithelium (RPE) in the mid phase of the angiogram. (medscape.com)
  • Note the even pigmentation of the retinal pigment epithelium and the absence of any yellow excrescences (drusen) in the fovea. (medscape.com)
  • A few areas of atrophy are noted, where the retinal pigment epithelium (RPE) has lost pigmentation. (medscape.com)
  • The neuroretina is tightly attached to the underlying retinal pigment only at the margins of the optic nerve and at the ora serrata. (medscape.com)
  • To study these conditions, his laboratory pursues two main strategies: neuroprotective strategy to save existing retinal neurons and neural regenerative strategy to produce new retinal neurons. (nih.gov)
  • Any damage to retinal neurons can have devastating consequences, including loss of vision. (nih.gov)
  • If our rods or rod system neurons become diseased and degenerated we become night blind as happens to unfortunate people who have a disease called retinitis pigmentosa. (utah.edu)
  • That is, rod photoreceptors out-number cone photoreceptors by orders of magnitude and the consequent second- and third-order neurons recruited for processing rod-driven vision outnumber the cone pathways neurons everywhere but in the central fovea. (utah.edu)
  • The retinal layer contains photoreceptors (rod cells and cone cells) as well as neurons that transmit the information to the optic nerve. (medcell.org)
  • light must actually traverse downstream neurons and support cells before hitting the photoreceptors. (medcell.org)
  • Consequently, the present research looked into whether SHH could be changed by purmorphamine within the transdifferentiation of Mller glial cells to retinal neurons, and therefore, attempted to give a far more convenient, stabilized and effective therapy. (exposed-skin-care.net)
  • The combined results indicate that glycolysis is regulated by the compartmental expression of hexokinase 2, pyruvate kinase M1, and pyruvate kinase M2 in photoreceptors, whereas the inner retinal neurons exhibit a lower capacity for glycolysis and aerobic glycolysis. (molvis.org)
  • Elevated intraocular pressure causes inner retinal dysfunction before cell loss in a mouse model of experimental glaucoma. (research.com)
  • The discovery of melanopsin-dependent inner retinal photoreceptors in mammals has precipitated a fundamental reassessment of such non-image forming (NIF) light responses as circadian photoentrainment and the pupil light reflex. (ox.ac.uk)
  • The retinal ganglion cells that subserve inner retinal photoreception (ipRGCs) project overwhelmingly to brain areas involved in NIF responses, indicating that, in terms of central signaling, their predominant function is non-image forming. (ox.ac.uk)
  • Here, we explore this second possibility by using melanopsin knockout (Opn4-/-) mice to examine the role of inner retinal photoreceptors in diurnal regulation of retinal function. (ox.ac.uk)
  • Anterior to the ora serrata, the retinal layer becomes a non-photosensitive epithelium. (medcell.org)
  • A signal travels to the brain via the retinal ganglion cell axons. (nih.gov)
  • What are intrinsic control mechanisms that lead to photoreceptor cell fate from retinal progenitors? (nih.gov)
  • Retinal and macular diseases are a major cause of visual impairment and affect the quality of life of millions worldwide. (nih.gov)
  • Hoping to develop a treatment that works more broadly across diseases, a Penn Vet team used canine disease models to closely examine how retinal gene activity varied during the progression of three different forms of inherited vision disease. (mvrf.org)
  • Their results turned up an unexpected commonality: Early on in each of the diseases, genes involved in the same specific pathway of cell death appeared to be activated. (mvrf.org)
  • These findings point to possible interventions that could curb vision loss across a variety of inherited retinal diseases. (mvrf.org)
  • All of these diseases involve the death of photoreceptor cells and each is caused by a distinct genetic mutation. (mvrf.org)
  • We wanted to get a better understanding of whether there are any common cell death or cell survival pathways that could be targeted in some of these diseases. (mvrf.org)
  • We assumed," Aguirre said, "the diseases would be different from one another and that cells would commit suicide by their own specific pathway and that perhaps quite late they would have a common final pathway. (mvrf.org)
  • Genini, Beltran and Aguirre say their results suggest that these drugs or similar ones might have a role to play in the retinal diseases they investigated and perhaps in others that their team is currently studying. (mvrf.org)
  • Both address the overall goal of engineering devices to establish light-sensitivity and vision in patients with photoreceptor degenerative diseases. (uic.edu)
  • The researchers sought to edit the genomes of neural retinal cells, particularly unhealthy or dying photoreceptors, in order to provide evidence for the genome-editing tool's potential application in treating retinal diseases. (scienceboard.net)
  • However, our study provides substantial evidence for the in vivo applicability of this new genome-editing strategy and its potential in diverse research and therapeutic contexts -- in particular for inherited retinal diseases such as retinitis pigmentosa," co-author Kai Yao, Wuhan University of Science and Technology professor, said in a statement. (scienceboard.net)
  • Precision genome editing agents can enable gene correction and disease rescue in inherited retinal diseases, according to University of California, Irvine. (scienceboard.net)
  • In a healthy eye, bipolar cells receive signals from photoreceptor cells across a synapse and then transmit this information either directly or indirectly to retinal ganglion cells. (nih.gov)
  • We are also interested in understanding photoreceptor morphogenesis and synapse formation. (nih.gov)
  • In normal rods, light-induced closure of CNG channels leads to hyperpolarization of the cell, reducing neurotransmitter release at the synapse. (duke.edu)
  • The A17 is characterized by always making a return synapse known as a reciprocal synapse to the rod bipolar axon terminal. (utah.edu)
  • Generating appropriate synapses between photoreceptor and bipolar cells is an essential step in restoring vision through photoreceptor transplantation. (nih.gov)
  • Electron microscopy of the rod bipolar cell axons in the inner plexiform layer shows that they make ribbon synapses only upon amacrine cell profiles (Fig. 8). (utah.edu)
  • The electron micrograph in the top panel shows two invaginating synapses between cone and horizontal cells in the outer p. (cellimagelibrary.org)
  • Some approaches involve the use of stem cells, progenitor cells, and novel materials. (nih.gov)
  • This project seeks to elucidate transcriptional and post-transcriptional regulatory networks that determine cell fate and guide the development of photoreceptors from retinal progenitor cells. (nih.gov)
  • We are now focused on delineating the transcription factors and signaling pathways that are responsible for generating photoreceptors from retinal progenitor cells. (nih.gov)
  • The two-year research project, "Nanoparticle-based Photo-activator of Voltage-gated Sodium Channels," will support development and testing of the device in nerve cell preparations including isolated cells obtained from rat retinas. (uic.edu)
  • While mouse retinal electroporation, both in vivo and ex vivo, has been developed and extensively described by Matsuda and Cepko(6-7,9), we have recently developed a simple approach to quantify the activity of photoreceptor-specific CREs in electroporated mouse retinas(10). (wustl.edu)
  • Most vertebrates have a preponderance of rod photoreceptors in their retinas and such animals are very good at hunting and movement at night because of their very sensitive scotopic visual systems. (utah.edu)
  • 1994). The immunocytochemical staining and confocal microscopy is now the most illustrative way of seeing the rod bipolar cells in mammalian retinas (Cuenca personal communication) (Fig. 7). (utah.edu)
  • By the age of four months, the retinas of control mice with uncorrected retinitis pigmentosa were observed to be thin and lacking in rod photoreceptors. (scienceboard.net)
  • But mice who had the PDE6β gene mutation corrected through the PE SpRY system had much thicker retinas containing numerous rod cells. (scienceboard.net)
  • Intrinsically photosensitive retinal ganglion cells (ipRGCs) are a subset of retinal ganglion cells that respond to light independently from rod and cone photoreceptor input. (indianactsi.org)
  • We now know that a small subset of retinal ganglion cells are directly photosensitive and utilize an opsin/vitamin A-based photopigment called melanopsin maximally sensitive in the blue part of the spectrum. (ox.ac.uk)
  • This loss of photoreceptors underlies the retinal abnormalities and progressive vision loss characteristic of vitelliform macular dystrophy. (medlineplus.gov)
  • This research has been extended to include how aging affects retinal and photoreceptor function. (nih.gov)
  • How the remodeled retinal circuit affects visual processing following rod rescue is not known. (duke.edu)
  • Although light affects rod photoreceptors primarily, cones seem to be more resilient surviving for a prolonged period of time after light exposure. (nature.com)
  • Abnormal lysosomal activation or inhibition has dramatic consequences on photoreceptor cell homeostasis and impacts extensive cellular function, which in turn affects vision. (irrf.org)
  • Ferroptosis is an iron-dependent cell death and affects efficacies of multiple antitumor regimens, showing a great potential in cancer therapy. (bvsalud.org)
  • CAR affects both rods and cones, whereas MAR is typically characterized by antibodies directed toward bipolar cells that interfere with rod function. (medscape.com)
  • The sensory primary cilium of vertebrate photoreceptor cells houses thousands of photosensitive disk membranes that are renewed continuously throughout our lifespan. (jneurosci.org)
  • In this next research phase they hope to identify genes and proteins that help or hinder this ability of retinal ganglion cells to regenerate, grow axons to a target and become functional in mice. (nih.gov)
  • Low-level gestational lead exposure increases retinal progenitor cell proliferation and rod photoreceptor and bipolar cell neurogenesis in mice. (cdc.gov)
  • While exposure of wt mice resulted in massive pyknosis in a focal region of the outer nuclear layer (ONL), the exposure of R91W;Nrl −/− mice led to additional cell death detected within the inner nuclear layer. (nature.com)
  • This was accompanied by retinal swelling and the appearance of cystoid spaces in both inner and ONLs of R91W;Nrl −/− mice indicating edema in affected areas. (nature.com)
  • Collectively, our data suggest that exposure of R91W;Nrl −/− mice to blue light not only induces cone cell death but also disrupts the inner blood-retinal barrier. (nature.com)
  • 4 Therefore, the impact of the R91W mutation on cones can be analyzed without the 'contaminating' presence of rods in R91W;Nrl −/− mice. (nature.com)
  • When assaying photoreceptor cis-regulatory activity, electroporation is usually performed in newborn mice (postnatal day 0, P0) which is the time of peak rod production(11-12). (wustl.edu)
  • By using electroretinography in wild-type mice, we describe diurnal rhythms in both the amplitude and speed of the retinal cone pathway that are a function of both prior light exposure and circadian phase. (ox.ac.uk)
  • The discovery that mice lacking rods and cones are capable of regulating their circadian rhythms by light provided the conceptual framework for the discovery of an entirely new photoreceptor system within the mammalian eye. (ox.ac.uk)
  • Progressive Retinal Atrophy rcd4 is an eye disease that is inherited in an autosomal recessive manner. (genocan.eu)
  • The increased density of cones in the fovea is accompanied by a sharp decline in the density of rods. (nih.gov)
  • In fact, the central 300 µm of the fovea, called the foveola , is totally rod-free. (nih.gov)
  • The extremely high density of cone receptors in the fovea , and the one-to- one relationship with bipolar cells and retinal ganglion cells (see earlier), endows this region (and the cone system generally) with the capacity to mediate high visual acuity. (nih.gov)
  • It is also the reason why disorders that affect the functioning of the fovea have such devastating effects on sight (see Box C ). Conversely, the exclusion of rods from the fovea, and their presence in high density away from the fovea, explain why the threshold for detecting a light stimulus is lower outside the region of central vision. (nih.gov)
  • Rods are present in greater numbers than cones from 2 mm from the fovea to the far periphery. (utah.edu)
  • Wayward bipolar cell dendrites establish contact with rods to support normal synaptic transmission, which is propagated to the retinal ganglion cells. (duke.edu)
  • As was pointed out in a previous section, only one morphological type of bipolar cell has been found to make connections with the rod photoreceptors. (utah.edu)
  • 6 , 7 High photon flux, oxygen tension and the high levels of polyunsaturated fatty acids present in rod outer segment membranes make rod photoreceptor cells especially vulnerable to photochemical damage. (nature.com)
  • A ) An illustration showing a rod photoreceptor cell and a zoomed-in view of the outer segment disc, where ABCA4 is located. (elifesciences.org)
  • His Anatomy research incorporates themes from Retinal Rod Photoreceptor Cells, Gap junction and Outer nuclear layer. (research.com)
  • This high density is achieved by decreasing the diameter of the cone outer segments such that foveal cones resemble rods in their appearance. (nih.gov)
  • A 48-Kd protein of the outer segment of the retinal rods and a component of the phototransduction cascade. (lookformedical.com)
  • The rod bipolar collects input from between 15 and 30 rod spherules in the outer plexiform layer (Fig. 3). (utah.edu)
  • Under current-clamp conditions, blocking h currents (hyperpolarization-activated cationic currents) with Cs + , Tl + , or ZD7288 hyperpolarized the resting potentials of cones and rods by ∼10 to 15 mV, and surprisingly generated spontaneous action potentials. (fujita-hu.ac.jp)
  • SCN2 Na + channel was observed in both cones and rods by single-cell RT-PCR analysis, suggesting that human photoreceptors express the SCN2 Na + channel. (fujita-hu.ac.jp)
  • The optic nerve carries signals generated by the photoreceptors (cones and rods). (msdmanuals.com)
  • A study at Penn, supported by MVRF, discovered that the same cell death pathway is involved in 3 forms of blindness. (mvrf.org)
  • But what scientists did not know is how the mutations trigger a molecular signaling pathway that leads to the death of photoreceptor cells. (mvrf.org)
  • In ciliated cells, including bovine and Xenopus laevis rod photoreceptors, P/rds was robustly sensitive to endoglycosidase H, which is consistent with its bypassing the medial Golgi and traversing the unconventional secretory pathway. (jneurosci.org)
  • It has been established that RGCs die by apoptosis in glaucoma, but the exact pathway from death stimulus to cell death is not understood. (uclahealth.org)
  • These results suggested that the endogenous neurogenic capacity of retinal Mller glial cells could be improved by this little molecular agonist from the SHH signaling pathway. (exposed-skin-care.net)
  • R&D Systems, Inc.) was added to purmorphamine-stimulated Mller glial cells to determine whether the Wnt pathway was involved. (exposed-skin-care.net)
  • Additionally, in vitro and vivo experiments validated PKD2 promoted proliferation, migration and invasion of LUAD cells. (bvsalud.org)
  • Following 2 days of culture, cells on the coverslips were fixed in 4% paraformaldehyde at 4C for 10 min and processed for immunocytochemistry to detect proliferation-associated markers. (exposed-skin-care.net)
  • Rod photoreceptors only contain one type of photopigment, rhodopsin, which has a peak sensitivity at a wavelength of approximately 500 nanometers which corresponds to blue-green light. (wikipedia.org)
  • The photoreceptor sensory cilium is recognized for fast membrane renewal, for which rhodopsin and peripherin/rds (P/rds) play critical roles. (jneurosci.org)
  • Because rhodopsin is known to traffic through conventional secretion, this study of P/rds suggests that both conventional secretion and unconventional secretion need to cooperate for the renewal of the photoreceptor sensory cilium. (jneurosci.org)
  • His Cell biology research incorporates elements of Rhodopsin, Retinal Rod Photoreceptor Cells, Endocrinology and TFEB. (research.com)
  • Researchers recently reported a technique that increases the regenerative capacity of retinal axons in a mouse model of optic nerve injury, a model commonly used to study glaucoma and other optic neuropathies. (nih.gov)
  • There exist three types of cone photoreceptors, each being maximally sensitive to a specific wavelength of light depending on the structure of their opsin photopigment. (wikipedia.org)
  • In the dark, 11- cis retinal binds the inert opsin. (elifesciences.org)
  • Light catalyzes the isomerization of 11- cis retinal to all- trans retinal, which is subsequently released from the activated opsin. (elifesciences.org)
  • It is a complex consisting of a molecule of ROD OPSIN and a molecule of 11-cis retinal (RETINALDEHYDE). (lookformedical.com)
  • A major cause of human blindness is the death of rod photoreceptors. (duke.edu)
  • However, most inherited forms of blindness, including retinitis pigmentosa, are caused by genetic defects in the photoreceptors themselves. (scienceboard.net)
  • This adaptation period is different between rod and cone cells and results from the regeneration of photopigments to increase retinal sensitivity. (wikipedia.org)
  • Strittmatter and his team also are searching for genes that contribute to the regeneration of axons from retinal ganglion cells. (nih.gov)
  • Cell adhesion molecules are known to play a pivotal role in assembling neural circuits. (nih.gov)
  • Furthermore, SHH-treated cells had been shifted to neural lineage by expressing neuron-specific course III -tubulin (Tuj1), directing cell destiny to pole Cbz-B3A cells (14). (exposed-skin-care.net)
  • In humans, rod cells are exclusively responsible for night vision as cone cells are only able to function at higher illumination levels. (wikipedia.org)
  • Cone cells are able to regain maximum retinal sensitivity in 9-10 minutes of darkness whereas rods require 30-45 minutes to do so. (wikipedia.org)
  • The various cone cells are maximally sensitive to either short wavelengths (blue light), medium wavelengths (green light), or long wavelengths (red light). (wikipedia.org)
  • It begins with the dysfunction and death of dim light-sensing rod cells, then spreads to the cone cells required for color vision, eventually leading to severe, irreversible vision loss. (scienceboard.net)
  • This protein is anchored to photoreceptor membranes in retinal cells and deactivates G proteins in the rod and cone phototransduction cascades. (utsouthwestern.edu)
  • The former edit allows for the purification of RGCs from retinal organoids derived from iPSCs, while the latter edit allows for the identification of ipRGCs among the broader RGC population. (indianactsi.org)
  • The human eye contains three types of photoreceptors, rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs). (wikipedia.org)
  • We previously discovered that that Maf-family bZIP transcription factor NRL is critical for rod photoreceptor fate and functional differentiation, and that loss of NRL leads to S-cones instead of rods. (nih.gov)
  • To address these questions, particularly in a human-relevant system, we have focused upon the use of human induced pluripotent stem cells (iPSCs) to assess their ability to give rise to RGCs, with a particular emphasis upon ipRGC differentiation. (indianactsi.org)
  • By immunostaining for cell type specific markers, I have documented the different stages of retinal differentiation and provided insight into the mechanisms of ipRGC differentiation. (indianactsi.org)
  • Different genes in the same functional clusters are expressed in the different developmental stages, suggesting that cells might change gene expression profiles from differentiation to maturation stages. (biomedcentral.com)
  • Subsequently, the cells were transferred to fresh culture medium, without purmorphamine or SHH-N, for a further 2 days to investigate Mller glia-derived cell differentiation. (exposed-skin-care.net)
  • Molecular cell. (arizona.edu)
  • To investigate this mechanism, electrophysiological and molecular biological techniques were used on human cone and rod photoreceptors. (fujita-hu.ac.jp)
  • The data confirmed that voltage-gated Na + channels were expressed not only in human rods but also in cones by electrophysiological and molecular biological experiments. (fujita-hu.ac.jp)
  • Dr. Piri's research is aimed toward understanding the molecular mechanisms leading to retinal ganglion cells (RGC) death in glaucoma. (uclahealth.org)
  • Gene and protein expression studies may lead to a better understanding of the regulatory events involved in RGC apoptosis, and provide molecular targets for the development of new therapeutic agents with neuroprotective effects in order to prevent or delay the loss of ganglion cells in glaucoma. (uclahealth.org)
  • Cone photoreceptors are conical in shape and contain cone opsins as their visual pigments. (wikipedia.org)
  • We are using state-of-the-art next generation sequencing combined with bioinformatic strategies, and developing stem cell-based approaches for gene therapy and drug discovery. (nih.gov)
  • Cells were initially edited by the CRISPR/Cas9 system to express the Thy1 gene at the Brn3b locus and the tdTomato gene at the melanopsin locus. (indianactsi.org)
  • It is unclear why mutations in this gene cause such a wide range of retinal abnormalities. (medlineplus.gov)
  • The spectrum of retinal dystrophies caused by mutations in the peripherin/RDS gene. (medlineplus.gov)
  • Cone-rod dystrophy, intrafamilial variability, and incomplete penetrance associated with the R172W mutation in the peripherin/RDS gene. (medlineplus.gov)
  • Among the later increased population, only about 40% genes are correlated with rod photoreceptors, indicating that multiple cell types contributed to gene expression in this phase. (biomedcentral.com)
  • The gene editing treatment prevented the death of rod and cone photoreceptors and restored normal electrical responses to light. (scienceboard.net)
  • French biotechnology firm GenSight Biologics is highlighting its lenadogene neparvovec (Lumevoq) and GS030 gene therapies at the Cell & Gene Meeting. (scienceboard.net)
  • Piri N, Gao Y, Danciger M, Mendoza E, Fishman GA, Farber DB: A transition of G to C in the 5' untranslated region of the cone cGMP-phosphodiesterase gamma subunit and cone-rod dystrophy. (uclahealth.org)
  • A retinal dystrophy belonging to the group of pigmentary retinopathies. (nih.gov)
  • There is no retinal tissue overlying the optic nerve head. (medscape.com)
  • Each photoreceptor is joined to the optic nerve by a tiny nerve branch. (msdmanuals.com)
  • The optic nerve is connected to nerve cells that carry signals to the vision center of the brain, where they are interpreted as visual images. (msdmanuals.com)
  • The central retinal vein exits the eye within the optic nerve. (msdmanuals.com)
  • Individuals with rod dysfunction have difficulty seeing in dim illumination (nyctalopia), prolonged dark adaptation, and peripheral field loss. (medscape.com)
  • Mutations in the genes encoding the CNGA3 and CNGB3 subunits of the cyclic nucleotide-gated (CNG) channel of cone photoreceptors have been associated with autosomal recessive achromatopsia. (jneurosci.org)
  • We also know that these photosensitive retinal ganglion cells mediate a broad range of physiological responses to light, ranging from the regulation of circadian rhythms to pupil constriction. (ox.ac.uk)
  • Such changes are broadly observed in blinding disorders caused by photoreceptor cell death and are thought to occur in response to deafferentation. (duke.edu)
  • SIGNIFICANCE STATEMENT Current strategies for treatment of neurodegenerative disorders are focused on the repair of the primary affected cell type. (duke.edu)
  • Paraneoplastic and autoimmune retinopathies belong to a spectrum of uncommon ophthalmic disorders in which autoantibodies directed at various retinal proteins cause progressive vision loss. (medscape.com)
  • Retinal disorders are often diagnosed and treated by an ophthalmologist. (msdmanuals.com)
  • First, temporally and spatially restricted tissue or cell patterns cause difficulties in dissecting target tissues or cells to collect enough RNA. (biomedcentral.com)
  • The retinal tissues were then digested in 0.25% trypsin and 0.1% type I collagenase at 37C for 5 min. (exposed-skin-care.net)
  • As rods degenerate, synaptic structures between rod and rod bipolar cells disappear and the rod bipolar cells extend their dendrites and occasionally make aberrant contacts. (duke.edu)
  • When peripherin 2 is altered or missing, photoreceptors break down (degenerate) over time. (medlineplus.gov)
  • Electron microscopic analysis confirms that indeed there are abnormal synaptic structures with less dendrites of rod bipolars innervating rod terminals in loss of Nfasc animals. (nih.gov)
  • His Retinal ganglion study combines topics in areas such as Amacrine cell, Receptive field, TRPV4 and Scotopic vision. (research.com)
  • Most commonly the output of the rod bipolar ribbon is to a dyad of amacrine cell processes, one of which is known as AII and the other as A17, a reciprocal amacrine (Figs. 8 and 9). (utah.edu)
  • abstract = "Background: Translating Ribosome Affinity Purification (TRAP), a method recently developed to generate cell type-specific translational profiles, relies on creating transgenic lines of animals in which a tagged ribosomal protein is placed under regulatory control of a cell type-specific promoter. (johnshopkins.edu)
  • All three genes encode key components of the phototransduction cascade in cone photoreceptors. (jneurosci.org)
  • They are receptor nerve cells that emit electrical signals when light hits them. (informit.com)
  • Disruption of Nfasc using a conditional knockout allele results in selective loss of pre- and post-synaptic proteins in the rod synaptic layer but not in the cone synaptic layer. (nih.gov)
  • Cell transdifferentiation methodology To examine the regenerative potential of Mller glial cells, 1104 cells/ml were plated on poly-D-lysine (500 g/ml) and laminin (5 g/ml) coated glass coverslips. (exposed-skin-care.net)
  • Development of Refractive Errors-What Can We Learn From Inherited Retinal Dystrophies? (harvard.edu)
  • This allows for both divergence of the rod signal and collection (convergence) of signals from many rods and rod bipolars, by means of these amacrine cells, before synaptic output to ganglion cells. (utah.edu)
  • The retinal distance circumferentially passing posteriorly from a point on the ora serrata to a point on the ora serrata 180 degrees away is approximately 50 mm. (medscape.com)