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1.
Nat Commun ; 11(1): 5247, 2020 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-33067436

RESUMO

Sleep spindle generation classically relies on an interplay between the thalamic reticular nucleus (TRN), thalamo-cortical (TC) relay cells and cortico-thalamic (CT) feedback during non-rapid eye movement (NREM) sleep. Spindles are hypothesized to stabilize sleep, gate sensory processing and consolidate memory. However, the contribution of non-sensory thalamic nuclei in spindle generation and the role of spindles in sleep-state regulation remain unclear. Using multisite thalamic and cortical LFP/unit recordings in freely behaving mice, we show that spike-field coupling within centromedial and anterodorsal (AD) thalamic nuclei is as strong as for TRN during detected spindles. We found that spindle rate significantly increases before the onset of rapid eye movement (REM) sleep, but not wakefulness. The latter observation is consistent with our finding that enhancing spontaneous activity of TRN cells or TRN-AD projections using optogenetics increase spindle rate and transitions to REM sleep. Together, our results extend the classical TRN-TC-CT spindle pathway to include non-sensory thalamic nuclei and implicate spindles in the onset of REM sleep.


Assuntos
Fenômenos Fisiológicos Oculares , Sono REM , Núcleos Talâmicos/fisiologia , Animais , Eletroencefalografia , Olho/química , Feminino , Masculino , Memória , Camundongos Endogâmicos C57BL , Optogenética , Núcleos Talâmicos/química , Tálamo/química , Tálamo/fisiologia , Vigília
2.
PLoS One ; 15(8): e0238146, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841295

RESUMO

We have previously developed a new theory for pressure dependent outflow from the human eye, and tested the model using experimental data at intraocular pressures above normal eye pressures. In this paper, we use our model to analyze a hypotensive pressure-time dataset obtained following application of a Honan balloon. Here we show that the hypotensive pressure-time data can be successfully analyzed using our proposed pressure dependent outflow model. When the most uncertain initial data point is removed from the dataset, then parameter estimates are close to our previous parameter estimates, but clearly parameter estimates are very sensitive to assumptions. We further show that (i) for a measured intraocular pressure-time curve, the estimated model parameter for whole eye surface hydraulic conductivity is primarily a function of the ocular rigidity, and (ii) the estimated model parameter that controls the rate of decrease of outflow with increasing pressure is primarily a function of the convexity of the monotonic pressure-time curve. Reducing parameter uncertainty could be accomplished using new technologies to obtain higher quality datasets, and by gathering additional data to better define model parameter ranges for the normal eye. With additional research, we expect the pressure dependent outflow analysis described herein may find applications in the differential diagnosis, prognosis and monitoring of the glaucomatous eye.


Assuntos
Pressão Intraocular/fisiologia , Modelos Biológicos , Fenômenos Fisiológicos Oculares , Bases de Dados Factuais , Olho/fisiopatologia , Glaucoma/diagnóstico , Glaucoma/fisiopatologia , Glaucoma/cirurgia , Humanos , Hidrodinâmica , Valores de Referência , Análise de Regressão , Fatores de Tempo , Tonometria Ocular
3.
Zhonghua Yan Ke Za Zhi ; 56(7): 481-488, 2020 Jul 11.
Artigo em Chinês | MEDLINE | ID: mdl-32842330

RESUMO

Vision is the receptive and cognitive process of converting light and pattern signals into nerve impulse signals. The main role of visual physiology is to elucidate the neural mechanism of vision. As an important part of visual physiology, visual electrophysiological examination, like electrocardiogram and electroencephalogram, is used to diagnose diseases through the bioelectrical phenomena generated during the activities of body organs and tissues. Since the founding of the People's Republic of China, remarkable achievements have been made in basic research, translational research and clinical research of visual physiology with more than 70 years of heritage and efforts. But there are still many unknown areas that need further exploration. Looking back at the development history will encourage us to forge ahead and make more contributions to visual physiology in China. Congratulations on the 70th anniversary of the founding of Chinese Journal of Ophthalmology. (Chin J Ophthalmol, 2020, 56: 481-488).


Assuntos
Fenômenos Fisiológicos Oculares , Oftalmologia , Grupo com Ancestrais do Continente Asiático , China , Humanos , Visão Ocular
4.
Med Sci (Paris) ; 36(8-9): 769-773, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32821054

RESUMO

The retina is the neurosensitive layer of the eye. In this tissue, photoreceptors convert light into nerve signals to be relayed to the brain. Despite retinal specialization in the treatment of light, excessive exposure can cause retinal damage, called retinal phototoxicity. In recent years, lighting devices rich in wavelengths of high energy (blue light) appeared, raising new concerns about retinal protection against light damage. We focus here on light-induced ocular diseases and the possible influence on visual health of new lighting technologies.


Assuntos
Olho/efeitos da radiação , Iluminação , Fenômenos Fisiológicos Oculares/efeitos da radiação , Adaptação Ocular/fisiologia , Adaptação Ocular/efeitos da radiação , Olho/fisiopatologia , Humanos , Invenções , Luz/efeitos adversos , Iluminação/efeitos adversos , Iluminação/métodos , Iluminação/tendências
5.
Proc Natl Acad Sci U S A ; 117(33): 19825-19829, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32759213

RESUMO

Suppose you are surreptitiously looking at someone, and then when they catch you staring at them, you immediately turn away. This is a social phenomenon that almost everyone experiences occasionally. In such experiences-which we will call gaze deflection-the "deflected" gaze is not directed at anything in particular but simply away from the other person. As such, this is a rare instance where we may turn to look in a direction without intending to look there specifically. Here we show that gaze cues are markedly less effective at orienting an observer's attention when they are seen as deflected in this way-even controlling for low-level visual properties. We conclude that gaze cueing is a sophisticated mental phenomenon: It is not merely driven by perceived eye or head motions but is rather well tuned to extract the "mind" behind the eyes.


Assuntos
Atenção , Fenômenos Fisiológicos Oculares , Percepção Social , Adulto , Sinais (Psicologia) , Feminino , Humanos , Intenção , Orientação Espacial , Visão Ocular
6.
Med Hypotheses ; 143: 110082, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32679424

RESUMO

A pandemic outbreak of a viral respiratory infection (COVID-19) caused by a coronavirus (SARS-CoV-2) prompted a multitude of research focused on various aspects of this disease. One of the interesting aspects of the clinical manifestation of the infection is an accompanying ocular surface viral infection, viral conjunctivitis. Although occasional reports of viral conjunctivitis caused by this and the related SARS-CoV virus (causing the SARS outbreak in the early 2000s) are available, the prevalence of this complication among infected people appears low (~1%). This is surprising, considering the recent discovery of the presence of viral receptors (ACE2 and TMPRSS2) in ocular surface tissue. The discrepancy between the theoretically expected high rate of concurrence of viral ocular surface inflammation and the observed relatively low occurrence can be explained by several factors. In this work, we discuss the significance of natural protective factors related to anatomical and physiological properties of the eyes and preventing the deposition of large number of virus-loaded particles on the ocular surface. Specifically, we advance the hypothesis that the standing potential of the eye plays an important role in repelling aerosol particles (microdroplets) from the surface of the eye and discuss factors associated with this hypothesis, possible ways to test it and its implications in terms of prevention of ocular infections.


Assuntos
Betacoronavirus , Conjuntivite Viral/prevenção & controle , Infecções por Coronavirus/prevenção & controle , Olho/virologia , Modelos Biológicos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Aerossóis , Microbiologia do Ar , Betacoronavirus/patogenicidade , Conjuntivite Viral/virologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Humanos , Potenciais da Membrana , Fenômenos Fisiológicos Oculares , Tamanho da Partícula , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Eletricidade Estática
7.
PLoS One ; 15(6): e0234117, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32525895

RESUMO

The goal of the study was to assess whether tonic immobility (TI)-induced stress reactions in laying hens can be reduced by probiotic supplementation and if the changes in body surface temperature, as a stress indicator, are genetically dependent and can be detected using infrared thermography (IRT). Seventy-one white and 70 brown hens were used. Hens were randomly assigned to three treatments at 1-day-old: beak trimmed and fed a regular diet; non-beak trimmed and fed a regular diet; and non-beak trimmed and fed a diet supplemented with probiotics, Bacillus subtilis. At 40 weeks of age, hens were tested for TI reactions. Eye and face temperatures were measured with IRT immediately before and after TI testing. Results revealed that the probiotic supplementation did not affect hens' stress responses to TI testing; the left and right eye temperatures increased by 0.26s°C and 0.15°C, respectively, while right face temperature tended to increase following TI testing. However, the right eye (32.60°C for white, and 32.35°C for brown) and face (39.51°C for white, and 39.36°C for brown) temperatures differed significantly among genetic lines. There was a positive correlation between TI duration and the changes of the left and right eye temperatures after TI testing in white hens. Based on these results, hens experienced TI-induced surface temperature changes that were detectable using IRT. White hens experienced greater stress reactions in response to TI than brown hens. However, supplementation with Bacillus subtilis did not attenuate hens' reaction to TI testing.


Assuntos
Bacillus subtilis/fisiologia , Probióticos/administração & dosagem , Estresse Fisiológico , Termografia/métodos , Animais , Temperatura Corporal , Galinhas , Suplementos Nutricionais , Raios Infravermelhos , Fenômenos Fisiológicos Oculares
8.
Science ; 368(6498)2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32586989

RESUMO

Neuronal circuits damaged or lost after injury can be regenerated in some adult organisms, but the mechanisms enabling this process are largely unknown. We used the planarian Schmidtea mediterranea to study visual system regeneration after injury. We identify a rare population of muscle cells tightly associated with photoreceptor axons at stereotyped positions in both uninjured and regenerating animals. Together with a neuronal population, these cells promote de novo assembly of the visual system in diverse injury and eye transplantation contexts. These muscle guidepost-like cells are specified independently of eyes, and their position is defined by an extrinsic array of positional information cues. These findings provide a mechanism, involving adult formation of guidepost-like cells typically observed in embryos, for axon pattern restoration in regeneration.


Assuntos
Axônios/fisiologia , Olho/citologia , Músculos/fisiologia , Fenômenos Fisiológicos Oculares , Células Fotorreceptoras de Invertebrados/fisiologia , Planárias/fisiologia , Regeneração , Animais
9.
Proc Natl Acad Sci U S A ; 117(26): 14682-14687, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32546523

RESUMO

We predict and experimentally verify an entoptic phenomenon through which humans are able to perceive and discriminate optical spin-orbit states. Direct perception and discrimination of these particular states of light with polarization-coupled spatial modes is possible through the observation of distinct profiles induced by the interaction between polarization topologies and the radially symmetric dichroic elements that are centered on the foveola in the macula of the human eye. A psychophysical study was conducted where optical states with a superposition of right and left circular polarization coupled to two different orbital angular momentum (OAM) values ([Formula: see text] and [Formula: see text]) were directed onto the retina of participants. The number of azimuthal fringes that a human sees when viewing the spin-orbit states is shown to be equal to the number (N) of radial lines in the corresponding polarization profile of the beam, where [Formula: see text] The participants were able to correctly discriminate between two states carrying OAM [Formula: see text] and differentiated by [Formula: see text] and [Formula: see text], with an average success probability of 77.6% (average sensitivity [Formula: see text], [Formula: see text], [Formula: see text]). These results enable methods of robustly characterizing the structure of the macula, probing retina signaling pathways, and conducting experiments with human detectors and optical states with nonseparable modes.


Assuntos
Fenômenos Fisiológicos Oculares , Retina/fisiologia , Percepção Visual/fisiologia , Humanos , Luz , Estimulação Luminosa , Teoria Quântica
11.
Chemosphere ; 258: 127409, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32569959

RESUMO

Perfluorobutanesulfonate (PFBS), an aquatic pollutant of emerging concern, is found to disturb gut microbiota, retinoid metabolism and visual signaling in teleosts, while probiotic supplementation can shape gut microbial community to improve retinoid absorption. However, it remains unknown whether probiotic bacteria can modulate the toxicities of PFBS on retinoid metabolism and visual physiology. In the present study, adult zebrafish were exposed for 28 days to 0, 10 and 100 µg/L PFBS, with or without dietary administration of probiotic Lactobacillus rhamnosus. Interaction between PFBS and probiotic was examined regarding retinoid dynamics (intestine, liver and eye) and visual stimuli transmission. PFBS single exposures remarkably inhibited the absorption of retinyl ester in female intestines, which were, however, restored by probiotic to normal status. Although coexposure scenarios markedly increased the hepatic storage of retinyl ester in females, mobilization of retinol was reduced in livers by single or combined exposures regardless of sex. In the eyes, transport and catalytic conversion of retinol to retinal and retinoic acid were interrupted by PFBS alone, which were efficiently antagonized by probiotic presumably through an indirect action. In response to the availability of retinal chromophore, transcriptions of opsins and arrestin genes were altered adaptively to control visual perception and termination. Neurotransmission across retina circuitry was changed accordingly, centering on epinephrine and norepinephrine. In summary, the present study found the efficient modulation of probiotic on retinoid metabolic disorders of PFBS pollution, which subsequently impacted visual signaling. A future work is warranted to provide mechanistic clues in retinoid interaction.


Assuntos
Fluorcarbonetos/toxicidade , Fenômenos Fisiológicos Oculares/efeitos dos fármacos , Probióticos/farmacologia , Retinoides/metabolismo , Ácidos Sulfônicos/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Olho/efeitos dos fármacos , Olho/metabolismo , Feminino , Metabolismo dos Lipídeos/efeitos dos fármacos , Opsinas/genética , Transdução de Sinais , Transcrição Genética/efeitos dos fármacos
12.
PLoS One ; 15(6): e0234313, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32516320

RESUMO

The ocular surface microbiome of veterinary species has not been thoroughly characterized using molecular-based techniques, such as next generation sequencing (NGS), as the vast majority of studies have utilized traditional culture-based techniques. To date, there is one pilot study evaluating the ocular surface of healthy dogs using NGS. Furthermore, alterations in the ocular surface microbiome over time and after topical antibiotic treatment are unknown. The objectives of this study were to describe the bacterial composition of the ocular surface microbiome in clinically normal dogs, and to determine if microbial community changes occur over time or following topical antibiotic therapy. Topical neomycin-polymyxin-bacitracin ophthalmic ointment was applied to one eye each of 13 adult dogs three times daily for seven days, while contralateral eyes served as untreated controls. The inferior conjunctival fornix of both eyes was sampled via swabbing at baseline prior to antibiotic therapy (day 0), after 1 week of treatment (day 7), and 4 weeks after discontinuing treatment (day 35). Genomic DNA was extracted from the conjunctival swabs and primers targeting the V4 region of bacterial 16S rRNA genes were used to generate amplicon libraries, which were then sequenced on an Illumina platform. Data were analyzed using Quantitative Insights Into Molecular Ecology (QIIME 2.0). At baseline, the most relatively abundant phyla sequenced were Proteobacteria (49.7%), Actinobacteria (25.5%), Firmicutes (12%), Bacteroidetes (7.5%), and Fusobacteria (1.4%). The most common families detected were Pseudomonadaceae (13.2%), Micrococcaceae (12%), Pasteurellaceae (6.9%), Microbacteriaceae (5.2%), Enterobacteriaceae (3.9%), Neisseriaceae (3.5%), and Corynebacteriaceae (3.3%). Alpha and beta diversity measurements did not differ in both control and treatment eyes over time. This report examines the temporal stability of the canine ocular surface microbiome. The major bacterial taxa on the canine ocular surface remained consistent over time and following topical antibiotic therapy.


Assuntos
Túnica Conjuntiva/microbiologia , Microbiota/efeitos dos fármacos , Microbiota/genética , Administração Tópica , Animais , Antibacterianos/administração & dosagem , Bacitracina/farmacologia , Bactérias/genética , Túnica Conjuntiva/efeitos dos fármacos , Primers do DNA , Cães/microbiologia , Olho/microbiologia , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Masculino , Neomicina/farmacologia , Fenômenos Fisiológicos Oculares , Polimixinas/farmacologia , RNA Ribossômico 16S/genética
13.
PLoS One ; 15(5): e0228365, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32421714

RESUMO

We investigated the global structure of intrinsic cross-frequency dynamics by systematically examining power-based temporal associations among a broad range of oscillation frequencies both within and across EEG-based current sources (sites). We focused on power-based associations that could reveal unique timescale dependence independently of interacting frequencies. Large spectral-power fluctuations across all sites occurred at two characteristic timescales, sub-second and seconds, yielding distinct patterns of cross-frequency associations. On the fast sub-second timescale, within-site (local) associations were consistently between pairs of ß-γ frequencies differing by a constant Δf (particularly Δf ~ 10 Hz at posterior sites and Δf ~ 16 Hz at lateral sites) suggesting that higher-frequency oscillations are organized into Δf amplitude-modulated packets, whereas cross-site (long-distance) associations were all within-frequency (particularly in the >30 Hz and 6-12 Hz ranges, suggestive of feedforward and feedback interactions). On the slower seconds timescale, within-site (local) associations were characterized by a broad range of frequencies selectively associated with ~10 Hz at posterior sites and associations among higher (>20 Hz) frequencies at lateral sites, whereas cross-site (long-distance) associations were characterized by a broad range of frequencies at posterior sites selectively associated with ~10 Hz at other sites, associations among higher (>20 Hz) frequencies among lateral and anterior sites, and prevalent associations at ~10 Hz. Regardless of timescale, within-site (local) cross-frequency associations were weak at anterior sites indicative of frequency-specific operations. Overall, these results suggest that the fast sub-second-timescale coordination of spectral power is limited to local amplitude modulation and insulated within-frequency long-distance interactions (likely feedforward and feedback interactions), while characteristic patterns of cross-frequency interactions emerge on the slower seconds timescale. The results also suggest that the occipital α oscillations play a role in organizing higher-frequency oscillations into ~10 Hz amplitude-modulated packets to communicate with other regions. Functional implications of these timescale-dependent cross-frequency associations await future investigations.


Assuntos
Comportamento/fisiologia , Córtex Cerebral/fisiologia , Eletroencefalografia , Fenômenos Fisiológicos Oculares , Adolescente , Adulto , Córtex Cerebral/diagnóstico por imagem , Feminino , Humanos , Masculino , Percepção , Visão Ocular/fisiologia , Adulto Jovem
14.
J Clin Neurosci ; 78: 313-316, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32354645

RESUMO

Many people with stroke (PwS) demonstrate reduced balance and increased postural sway afterwards, which may ultimately lead to falls and injury. In this study, we aimed to better understand postural sway behavior and the mechanisms of balance control by examining balance in upright standing among PwS using methods from statistical mechanics i.e., the Stabilogram diffusion analysis (SDA). Center-of-pressure displacements while standing still were measured in 25 PwS and 11 healthy subjects. The traditional postural sway parameters were measured, and the SDA was used to characterize balance control in eyes-open and eyes-closed conditions. We found that PwS demonstrated significantly greater postural sway in the mediolateral and anterior-posterior directions and significantly higher SDA short-term diffusion coefficients and critical displacement in both eyes-open and eyes-closed conditions. There was also a significant group-by-condition interaction, whereas PwS demonstrated more sway in the eyes-closed condition. The SDA analysis revealed unstable behavior during short-term intervals, interpreted as larger distance of sway until closed-loop control took place. This significant group-by-condition interaction suggests that PwS have a significantly greater reliance on visual input compared with healthy subjects.


Assuntos
Equilíbrio Postural/fisiologia , Postura/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Acidentes por Quedas/prevenção & controle , Adulto , Estudos de Casos e Controles , Olho , Feminino , Voluntários Saudáveis , Humanos , Masculino , Fenômenos Fisiológicos Oculares , Posição Ortostática
15.
Zoolog Sci ; 37(2): 177-192, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32282149

RESUMO

There are few model fish that are both edible and suitable for use in the laboratory. The Japanese loach (Misgurnus anguillicaudatus) is a traditional food in Japan, but is highly neglected despite its great nutritional value. To understand its circadian system and photic input pathway for synchronization of physiological activities to environmental light-dark cycles, we measured locomotor activity under light-dark and constant dark (DD) conditions. Locomotor activity was found to be higher in the nighttime than daytime, and its rhythmicity was weakened under DD conditions. The nocturnal activity of the Japanese loach is mainly controlled by environmental light, rather than the circadian clock. We explored the circadian regulation and light-responsiveness of clock gene expression in the eyes of loaches. The daily expression profiles of its mRNA revealed that most of the examined Cry and Per genes were likely regulated by internal circadian and/or environmental light signals. Among the Opsin genes transcribed in the eye, we detected the retinal photopigment porphyropsin at the protein level, which was lower than in mice. This property of loach eyes prompted us to analyze the locomotor activities of eye-enucleated fish. As a result, they still showed nocturnal circadian activity. Thus, it is likely that extraocular photoreceptive tissue(s) also contribute to the photic input pathway, although loach eyes are a circadian photosensitive tissue. This suggests that the loach mainly uses not its vision but other stimuli, such as mechanical or chemical stimuli, detected by barbels, to coordinate its nocturnal behavior.


Assuntos
Relógios Circadianos/genética , Cipriniformes/genética , Animais , Relógios Circadianos/fisiologia , Ritmo Circadiano/fisiologia , Cipriniformes/fisiologia , Olho/química , Olho/metabolismo , Feminino , Proteínas de Peixes/metabolismo , Regulação da Expressão Gênica , Luz , Locomoção/fisiologia , Masculino , Fenômenos Fisiológicos Oculares , RNA Mensageiro
16.
Open Vet J ; 9(4): 301-308, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32042649

RESUMO

Body temperature is an important component in the diagnosis and treatment of disease in canines. The rectal temperature remains the standard of obtaining temperature within the clinical setting, but there are many drawbacks with this method, including time, access, animal stress, and safety concerns. Interest in using infrared thermometry in canines to obtain body temperature has grown as animal scientists and veterinarians search for non-invasive and non-contact methods and locations of obtaining canine temperatures. Here, we review evidence on axillary, auricular, and ocular region canine thermometry and the degree to which measurements in these locations are representative of rectal temperature values. Instrumentation refinement and development, as well as morphologic differences, play an important role in the potential correlation between the rectal temperature and these other locations. These caveats have yet to be fully addressed in the literature, limiting the options for those seeking alternatives to rectal thermometry.


Assuntos
Axila/fisiologia , Cães/fisiologia , Fenômenos Fisiológicos Oculares , Termografia/veterinária , Animais , Febre/diagnóstico , Reto/fisiologia , Termografia/instrumentação , Termometria/instrumentação , Termometria/veterinária
17.
Philos Trans A Math Phys Eng Sci ; 378(2167): 20190442, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32008449

RESUMO

The optical systems mimicking the eye functions are of great importance in various applications including consumer electronics, medical equipment, machine vision systems and robotics. This optics offers advantages over traditional optical technologies such as the superior adaptation to changing conditions and the comprehensive range of functional characteristics at miniature sizes. This paper presents a review on the recent progress in the development of human eye-inspired optical systems. Liquid-based and elastomer-based tunable optical elements are discussed with the focus on the actuation mechanism, optical performance and the possibility of integration into artificial eye systems. This article is part of the theme issue 'Bioinspired materials and surfaces for green science and technology (part 3)'.


Assuntos
Materiais Biomiméticos , Biomimética/instrumentação , Olho/anatomia & histologia , Fenômenos Fisiológicos Oculares , Dispositivos Ópticos , Eletrônica , Desenho de Equipamento , Humanos , Robótica , Visão Ocular
18.
Arch. Soc. Esp. Oftalmol ; 95(2): 84-89, feb. 2020. ilus, graf
Artigo em Espanhol | IBECS | ID: ibc-195331

RESUMO

La dopamina es sintetizada por la tirosina hidroxilasa y es considerada como una catecolamina mayor en la retina de los vertebrados, incluyendo el pez cebra. Sin embargo, se conoce poco sobre la función del receptor de dopamina D2 (DRD2) en la fisiología retiniana. Por lo tanto, para dilucidar el papel del DRD2 en el desarrollo y la función de los ojos en el pez cebra, los peces fueron expuestos a la flufenazina, quinpirol, o la combinación de ambos, y luego se evaluó el tamaño del ojo, el diámetro del nervio óptico (ONd) y la adaptación visual al fondo. Los resultados mostraron que la flufenazina (flufenazina, antagonista DRD2) disminuyó el tamaño del ojo y el diámetro del nervio óptico seguido de una interrupción de la función visual. La adición de quinpirol (quinpirol, agonista DRD2) invirtió los efectos causados por flufenazina, lo que implica que DRD2 es necesario para el desarrollo y la función normal del ojo en el pez cebra. Considerando el papel de las neuronas dopaminérgicas en el desarrollo y la función de la retina, la disfunción de las vías de señalización de las neuronas dopaminérgicas en la retina puede causar anormalidades visuales, particularmente en la participación de la dopamina en la regulación de la respuesta de la luz


Dopamine is synthesized by tyrosine hydroxylase and is considered as a major catecholamine in the vertebrate retina, including zebrafish. However, little is known about the role of dopamine D2 receptor (DRD2) in retinal physiology. Therefore, to elucidate the role of DRD2 in the eye development and function in zebrafish, fish were exposed to fluphenazine, quinpirole, or combination of both. Subsequently, the eye size, optic nerve diameter (ONd), and visual background adaptation were evaluated. The results showed that fluphenazine (fluphenazine, DRD2 antagonist) decreased eye size and optic nerve diameter followed by disruption of visual function. The addition of Quinpirole (quinpirole, DRD2 agonist) reversed the effects caused by fluphenazine, implying that DRD2 is necessary for normal eye development and function in zebrafish. Considering the role of dopaminergic neurons in retinal development and function, dysfunction of dopaminergic neuron signaling pathways in the retina may cause visual abnormalities, particularly in the involvement of dopamine in regulating light response


Assuntos
Animais , Antagonistas dos Receptores de Dopamina D2/farmacologia , Olho/embriologia , Fenômenos Fisiológicos Oculares , Receptores de Dopamina D2/fisiologia , Olho/anatomia & histologia , Olho/crescimento & desenvolvimento , Flufenazina/farmacologia , Imuno-Histoquímica , Tamanho do Órgão , Quimpirol/farmacologia
19.
Sci Rep ; 10(1): 712, 2020 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-31959829

RESUMO

Functional near-infrared spectroscopy (fNIRS), an imaging tool that utilizes infrared light to measure changes within the concentration of oxygenated (HbO) and deoxygenated (HbR) hemoglobin, holds promise to study functional activity from motor, visual, and memory cortical regions using stimulus-induced tasks. This study investigated the reliability for fNIRS to examine cortical activations within the frontal eye fields (FEF) while initiating vergence eye movements, the inward and outward rotation of the eyes. FNIRS data were collected from twenty participants with normal binocular vision while performing vergence eye movements compared to sustained gaze fixation within a block design during two different sessions. Reliability of the experimental protocol was assessed using the intraclass correlation coefficient (ICC). The ICC values ranged from 0.6 to 0.7 for measuring the HbO activation within the vicinity of the FEF. A frequency power spectrum analysis revealed two predominant frequencies within the functional activation signals from the FEF. One high-intensity signal was present at 0.029 Hz, centering around the block design frequency. The peak-intensity signal was observed between 0.012 and 0.018 Hz where this very low-frequency oscillation (VLFO) was hypothesized to be generated by the macrovasculature present near the FEF and should be avoided as a block design frequency in future fNIRS studies to avoid false positive results.


Assuntos
Movimentos Oculares/fisiologia , Lobo Frontal/fisiologia , Fenômenos Fisiológicos Oculares , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Visão Binocular/fisiologia , Córtex Visual/fisiologia , Adulto , Reações Falso-Positivas , Feminino , Fixação Ocular , Humanos , Masculino , Reprodutibilidade dos Testes , Rotação , Adulto Jovem
20.
Arch Soc Esp Oftalmol ; 95(2): 84-89, 2020 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31955999

RESUMO

Dopamine is synthesized by tyrosine hydroxylase and is considered as a major catecholamine in the vertebrate retina, including zebrafish. However, little is known about the role of dopamine D2 receptor (DRD2) in retinal physiology. Therefore, to elucidate the role of DRD2 in the eye development and function in zebrafish, fish were exposed to fluphenazine, quinpirole, or combination of both. Subsequently, the eye size, optic nerve diameter (ONd), and visual background adaptation were evaluated. The results showed that fluphenazine (fluphenazine, DRD2 antagonist) decreased eye size and optic nerve diameter followed by disruption of visual function. The addition of Quinpirole (quinpirole, DRD2 agonist) reversed the effects caused by fluphenazine, implying that DRD2 is necessary for normal eye development and function in zebrafish. Considering the role of dopaminergic neurons in retinal development and function, dysfunction of dopaminergic neuron signaling pathways in the retina may cause visual abnormalities, particularly in the involvement of dopamine in regulating light response.


Assuntos
Antagonistas dos Receptores de Dopamina D2/farmacologia , Olho/embriologia , Fenômenos Fisiológicos Oculares , Receptores de Dopamina D2/fisiologia , Animais , Olho/anatomia & histologia , Olho/crescimento & desenvolvimento , Flufenazina/farmacologia , Imuno-Histoquímica , Tamanho do Órgão , Quimpirol/farmacologia
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