Autonomic Control of the Eye

Comprehensive physiology, Journal Year: 2014, Volume and Issue: unknown, P. 439 - 473

Published: Dec. 23, 2014

The autonomic nervous system influences numerous ocular functions. It does this by way of parasympathetic innervation from postganglionic fibers that originate neurons in the ciliary and pterygopalatine ganglia, sympathetic superior cervical ganglion. Ciliary ganglion project to body sphincter pupillae muscle iris control accommodation pupil constriction, respectively. Superior dilator dilation. Ocular blood flow is controlled both via direct on vasculature optic nerve, choroid, body, iris, as well indirect retinal flow. In mammals, innervated vasodilatory ganglion, vasoconstrictive Intraocular pressure regulated primarily through balance aqueous humor formation outflow. Autonomic regulation vessels epithelium an important determinant formation; trabecular meshwork episcleral These tissues are all ganglia. addition these classical pathways, trigeminal sensory exert local, intrinsic many regions eye, some within

Language: Английский

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Standards in Pupillography

Frontiers in Neurology, Journal Year: 2019, Volume and Issue: 10

Published: Feb. 21, 2019

The number of research groups studying the pupil is increasing, as publications. Consequently, new standards in pupillography are needed to formalize methodology including recording conditions, stimulus characteristics, well suitable parameters evaluation. Since description intrinsically photosensitive retinal ganglion cells (ipRGCs) there has been an increased interest and broader application ophthalmology other fields psychology chronobiology. Colour plays important role not only but also clinical observational therapy studies like gene hereditary degenerations psychopathology. Stimuli can vary size, brightness, duration, wavelength. Stimulus paradigms determine whether rhodopsin-driven rod responses, opsin-driven cone or melanopsin-driven ipRGC responses primarily elicited. Background illumination, adaptation state, instruction for participants will furthermore influence results. This standard recommends a minimum set variables be used specified publication methodologies. Initiated at 32nd International Pupil Colloquium 2017 Morges, Switzerland, aim this manuscript outline based on current knowledge experience experts order achieve greater comparability pupillographic studies. Such particularly facilitate proper by researchers field. First we describe general standards, followed specific suggestions concerning demands different targets research: afferent efferent reflex arc, pharmacology, psychology, sleepiness-related animal

Language: Английский

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Opponent melanopsin and S-cone signals in the human pupillary light response

Proceedings of the National Academy of Sciences, Journal Year: 2014, Volume and Issue: 111(43), P. 15568 - 15572

Published: Oct. 13, 2014

Significance Our eyes sense bright light using cones (L, M, and S) recently discovered melanopsin-containing ganglion cells. Both S melanopsin respond to blueish (short-wavelength) light. How does interact with the in visual function? We measured response of human pupil isolated stimulation different photoreceptors. work reveals a curious, opponent blue otherwise familiar pupillary response. Increased can cause dilate, but this effect is usually masked by stronger opposite from results have clinical importance because sensing known be related seasonal depression, sleep, pain

Language: Английский

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Vision under mesopic and scotopic illumination

Frontiers in Psychology, Journal Year: 2015, Volume and Issue: 5

Published: Jan. 22, 2015

Evidence has accumulated that rod activation under mesopic and scotopic light levels alters visual perception performance. Here we review the most recent developments in measurement of cone contributions to color temporal processing, with a focus on data measured using four-primary photostimulator method independently controls excitations. We discuss findings context inputs three primary retinogeniculate pathways understand vision. Additionally, present evidence hue is possible scotopic, pure rod-mediated conditions involves cortical mechanisms.

Language: Английский

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The Post-Illumination Pupil Response (PIPR)

Investigative Ophthalmology & Visual Science, Journal Year: 2015, Volume and Issue: 56(6), P. 3838 - 3838

Published: June 11, 2015

Purpose.: The post-illumination pupil response (PIPR) has been quantified using four metrics, but the spectral sensitivity of only one is known; here we determine other three. To optimize human PIPR measurement, protocol producing largest PIPR, duration and metric(s) with lowest coefficient variation. Methods.: consensual light reflex (PLR) was measured a Maxwellian view pupillometer. Experiment 1: Spectral metrics (plateau, 6 seconds, area under curve early late recovery) determined from criterion to 1-second pulse fitted vitamin A1 nomogram (λmax = 482 nm). 2: PLR as function three stimulus durations (1 second, 10 30 seconds), five irradiances spanning low high melanopsin excitation levels (retinal irradiance: 9.8–14.8 log quanta.cm−2.s−1), two wavelengths, (465 nm) (637 excitation. Intra- interindividual coefficients variation (CV) were calculated. Results.: (opn4) photopigment adequately describes all metrics. amplitude short-wavelength pulses (≥12.8 quanta.cm−2.s−1). plateau 6-second showed least intra- CV (≤0.2). maximum sustained 83.0 ± 48.0 seconds (mean SD) for 180.1 106.2 30-second nm; 14.8 Conclusions.: All current provide direct measure intrinsic photoresponse. progressive changes in disease, recommend that be short-duration (e.g., ≤1 second) analyzed and/or Our data baseline selection interstimulus intervals between consecutive testing sequences.

Language: Английский

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Diverse Cell Types, Circuits, and Mechanisms for Color Vision in the Vertebrate Retina

Physiological Reviews, Journal Year: 2019, Volume and Issue: 99(3), P. 1527 - 1573

Published: May 29, 2019

Synaptic interactions to extract information about wavelength, and thus color, begin in the vertebrate retina with three classes of light-sensitive cells: rod photoreceptors at low light levels, multiple types cone that vary spectral sensitivity, intrinsically photosensitive ganglion cells contain photopigment melanopsin. When isolated from its neighbors, a photoreceptor confounds photon flux wavelength so by itself provides no color. The has evolved elaborate color opponent circuitry for extracting comparing activities different broadly tuned parts visible spectrum. We review studies concerning circuit mechanisms mediating range species, tetrachromatic fish diverse cell common dichromatic mammals where opponency is restricted subset specialized circuits. Distinct among mammals, primates have reinvented trichromatic vision using novel strategies incorporate evolution an additional gene into foveal structure supports high-resolution vision. Color absent scotopic levels when only rods are active, but interact signals influence perception mesopic levels. Recent evidence suggests melanopsin-mediated signals, which been identified as substrate setting circadian rhythms, may also perception. consider circuits mediate these interactions. While relatively simple neural computation, it implemented vertebrates not yet fully understood.

Language: Английский

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Melanopsin-Expressing Intrinsically Photosensitive Retinal Ganglion Cells in Retinal Disease

Optometry and Vision Science, Journal Year: 2014, Volume and Issue: 91(8), P. 894 - 903

Published: May 30, 2014

Melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) are a class of photoreceptors with established roles in non–image-forming processes. Their contributions to image-forming vision may include the estimation brightness. Animal models have been central for understanding physiological mechanisms ipRGC function and there is evidence conservation across species. Intrinsically can be divided into five cell subtypes that show morphological functional diversity. Research humans has ipRGCs signal environmental irradiance entrain body clock solar day regulating circadian processes sleep. In addition, mediate pupil light reflex (PLR), making PLR readily accessible behavioral marker activity. Less known about optic nerve disease, emerging research providing insight their diabetes, retinitis pigmentosa, glaucoma, hereditary neuropathy. We briefly review anatomical distributions, projections, basic proposed functions animals without eye disease. introduce paradigm differentiating inner outer inputs pupillary control pathway disease apply this patients age-related macular degeneration (AMD). these cases AMD, we provide initial altered dysfunction more pronounced advanced Our perspective refined pupillometry paradigms, extended AMD assessment as tool measurement dysfunction.

Language: Английский

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A five-primary photostimulator suitable for studying intrinsically photosensitive retinal ganglion cell functions in humans

Journal of Vision, Journal Year: 2015, Volume and Issue: 15(1), P. 27 - 27

Published: Jan. 26, 2015

Intrinsically photosensitive retinal ganglion cells (ipRGCs) can respond to light directly through self-contained photopigment, melanopsin. IpRGCs also receive synaptic inputs from rods and cones. Thus, studying ipRGC functions requires a novel photostimulating method that account for all of the photoreceptor inputs. Here, we introduced an inexpensive LED-based five-primary photostimulator control excitations rods, S-, M-, L-cones, melanopsin-containing ipRGCs in humans at constant background excitation levels, critical requirement adaptation behavior with rod, cone, or melanopsin input. We described theory technical aspects (including optics, electronics, software, calibration) photostimulator. Then presented two preliminary studies using have implemented measure melanopsin-mediated pupil responses temporal contrast sensitivity function (TCSF). The results showed S-cone input was antagonistic L-, M- inputs, consistent S-OFF (L + M)-ON response property primate (Dacey et al., 2005). In addition, TCSF had distinctive pattern compared L M mediated TCSF. Other than controlling individual independently, has flexibility presenting stimuli modulating any combination excitations, which allows researchers study mechanisms by combine various

Language: Английский

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Exploiting metamerism to regulate the impact of a visual display on alertness and melatonin suppression independent of visual appearance

SLEEP, Journal Year: 2018, Volume and Issue: 41(8)

Published: May 18, 2018

Abstract Objectives Artificial light sources such as visual display units (VDUs) elicit a range of subconscious and reflex responses, including increases in alertness suppression pineal melatonin. Such responses employ dedicated retinal circuits encompassing melanopsin photoreceptors. Here, we aimed to determine whether this arrangement can be exploited modulate the impact VDUs on melatonin onset without altering appearance. Methods We generated five-primary VDU capable presenting metameric movies (matched for color luminance) but varying melanopic-irradiance. Healthy human participants (n = 11) were exposed from 18:00 23:00 hours at high- or low-melanopic setting randomized cross-over design measured salivary self-reported sleepiness 30-minute intervals. Results Our presented 3× adjustment melanopic-irradiance images matched photometrically luminance. Participants reported no significant difference appearance (color glare) between conditions. During time which was viewed, levels increased significantly, would expected phase diurnal cycle. The magnitude increase both parameters significantly enhanced when reduced. Conclusions data demonstrate that modulated independent photometric under commonly encountered exposure scenario (evening use VDU). They provide first demonstration production controlled independently experience, establish achieving objective.

Language: Английский

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Form vision from melanopsin in humans

Nature Communications, Journal Year: 2019, Volume and Issue: 10(1)

Published: May 22, 2019

Abstract Detection and discrimination of spatial patterns is thought to originate with photoreception by rods cones. Here, we investigated whether the inner-retinal photoreceptor melanopsin could represent a third origin for form vision. We developed 4-primary visual display capable presenting differing in contrast vs cones, generated spectrally distinct stimuli that were indistinguishable cones (metamers) but presented melanopsin. Healthy observers detect sinusoidal gratings formed these metamers when peripheral retina at low (≤0.8 cpd) temporal (≤0.45 Hz) frequencies, Michelson contrasts ≥14% Metameric became invisible lower light levels (<10 13 photons cm −2 sr −1 s ) are more active. The addition metameric increases altered appearance greyscale representations coarse range everyday images. These data identify as new potential aspects vision humans.

Language: Английский

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