Consulta: subjectFacets:"Retina"
Registros recuperados: 38
Data/hora: 09/06/2024 17:12:10

Cloning and retinal expression of melatonin receptors in the European sea bass, Dicentrarchus labrax
Provedor de dados: 5
Autores: Sauzet, S; Besseau, L; Perez, P; Coves, Denis; Chatain, Beatrice; Peyric, E; Boeuf, G; Munoz Cueto, J; Falcon, J.
Melatonin contributes to synchronizing behaviors and physiological functions to daily and seasonal rhythm in fish. However, no coherent vision emerges because the effects vary with the species, sex, moment of the year or sexual cycle. And, scarce information is available concerning the melatonin age, receptors, which is crucial to our understanding of the role melatonin plays. We report here the full length cloning of three different melatonin receptor subtypes in the sea bass Dicentrarchus labrax, belonging, respectively, to the MT1, MT2 and Mellc subtypes. MT1, the most abundantly expressed, was detected in the central nervous system, retina, and gills. MT2 was detected in the pituitary gland, blood cells and, to a lesser extend, in the optic tectum,...
Tipo: Text
Palavras-chave: Retina; Melatonin receptors; Sea bass.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4513.pdf

Estudio Morfológico de la Retina de Salmones (Salmo salar)
Provedor de dados: 77
Autores: Pellón,Mario; Rojas,Mariana; Yaikin,Pabla; del Sol,Mariano.
La retina de peces teleósteos como pez cebra, se ha transformado en un importante modelo para el estudio de la plasticidad neuronal y la neurogénesis. Se ha demostrado además que la retina experimenta cambios ontogenéticos para adaptarse a distintos medios ambientes durante su vida. Este estudio tiene como objetivo describir el desarrollo ontogenético de la retina del alevín de salmón desde la eclosión hasta la fase de juvenil. Se trabajó con 30 salmones divididos en tres grupos de 10. Grupo I: recién eclosionados, con saco vitelino y 18 mm de longitud. Grupo II: sin saco vitelino y 30 mm de longitud. Grupo III: 100 mm de longitud. Cinco alevinesde cada grupo fueron procesados según el protocolo de Hanken &amp;amp; Wassersug para medir los diámetros...
Tipo: Journal article
Palavras-chave: Retina; Ojo; Alevín; Peces teleósteos; Salmón; Desarrollo.
Ano: 2015
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022015000200058

Protective Effects of Ganoderma lucidum on the Changes Made in the Retinal Damage Induced by Traumatic Head Injury
Provedor de dados: 77
Autores: Özevren,Hüseyin; Deveci,Engin.
Head trauma affects the optic nerve visual function and visual acuity. As a result of head trauma occurring in the retina of the various biochemical, histological and immunohistochemical effects were investigated. The protective effect of Ganoderma lucidum was evaluated on the damage to the retina of the rats. Sprague-Dawley rats were subjected to traumatic brain injury with a weight-drop device using 300 g-1 m weight-height impact. Thirty rats were divided into three groups as group 1 control, 2 group trauma, 3 group trauma+Gonoderma lucidum (20 mL/kg per day via gastric gavage) Ganoderma lucidum was administered for 7 days after trauma.All rats were decapitated 5 days after the induction of trauma, and the protective effects of Ganoderma lucidum in...
Tipo: Journal article
Palavras-chave: Head trauma; Retina; Ganoderma lucidum; Rat.
Ano: 2017
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022017000300040

Morphology of the Eyeball, Orbit and Retina of Atlantic Salmon (Salmo Salar) Alevins under Hypoxic Conditions
Provedor de dados: 77
Autores: Pellón,Mario; Rojas,Mariana; Saint-Pierre,Gustavo; Hartley,Ricardo; del Sol,Mariano.
It has been demonstrated that hypoxia retards the growth of fish, reduces the survival of their larvae, deforms their vertebral column, but despite this teleost fish have the ability to completely regenerate many of their tissues, particularly the retina. As we do not have enough information about the effects of hypoxia on the eyeball, orbit and retina of Atlantic salmon (Salmo salar), we propose the following objectives: 1) Compare the morphological changes of the eyeball of fish subject to hypoxia and normoxia. 2) Determine changes in the orbit structure. 3) Describe the retina of salmon alevins. 4). Recognize hypoxic cells using the anti-Hif1a antibody in the retina of alevins as a sensor. 5) Determine the Shh morphogenic expression in alevins exposed...
Tipo: Journal article
Palavras-chave: Eyeball; Orbit; Retina; Salmo salar; Hypoxia; HIF1a; Shh.
Ano: 2016
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022016000100046

Study on Comparative Histology of Retinas in Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus, and Columba livia
Provedor de dados: 77
Autores: She,Qiusheng; An,Zhenqiang; Xia,Chengqiang; Kong,Yunfei; Chen,Enxiang.
The objective of this study was to explore the relationship between the retinal structure and its life adaptation to the environment of Ctenopharyngodon idella, Cynops orientalis, Bufo bufo gargarizans, Gekko japonicus and Columba livia . Measuring retinal thickness of each layer, the nuclei layer, and the diameter of each nuclear layer of the five animals, the statistical data analysis shows that: the nuclei layers of five animals are all 4, and their structures can be divided to 10 layers when observing with optical microscope. The retinal thickness of Ctenopharyngodon idella was 190.49 mm, Cynops orientalis was 173.07 µm, and the Bufo bufo gargarizans was 195.06 µm, Gekko japonicus was 224.32 µm and Columba livia was 174.10 µm. The number of retinal...
Tipo: Journal article
Palavras-chave: Ctenopharyngodon idella; Cynops orientalis; Bufo bufo gargarizans; Gekko japonicas; Columba livia; Retina; Comparative histology.
Ano: 2014
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022014000300028

Apoptosis Durante el Desarrollo Embrionario de la Retina de Tortuga (Trachemys scripta elegans)
Provedor de dados: 77
Autores: Segovia,Y.
La apoptosis o muerte celular programada es un proceso que ocurre durante el desarrollo del sistema nervioso. El objetivo de este estudio fue observar los patrones de apoptosis que se producen durante el desarrollo embrionario de la retina, desde el estadio S16 al momento del nacimiento, mediante miscoscopía óptica y electrónica. Se utilizaron retinas de embriones de tortuga. Nuestros datos muestran que los primeros signos de apoptosis comienzan en el estadio S16, en la capa nuclear interna y alcanzan su máxima densidad tanto en la capa nuclear interna como en la capa de células ganglionares en S20, para extinguirse, prácticamente, en el momento del nacimiento. Por otra parte, la apoptosis sigue un gradiente centro-periferia.
Tipo: Journal article
Palavras-chave: Trachemys scripta elegans; Apoptosis; Retina; Tortuga.
Ano: 2015
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022015000100020

Effects of Monocular Deprivation on the Dendritic Features of Retinal Ganglion Cells
Provedor de dados: 77
Autores: Mwachaka,Philip; Saidi,Hassan; Odula,Paul; Mandela,Pamela.
Monocular deprivation results in anatomical changes in the visual cortex in favor of the non-deprived eye. Although the retina forms part of the visual pathway, there is scarcity of data on the effect of monocular deprivation on its structure. The objective of this study was to describe the effects of monocular deprivation on the retinal ganglion cell dendritic features. The study design was quasi-experimental. 30 rabbits (18 experimental, 12 controls) were examined. Monocular deprivation was achieved through unilateral lid suture in the experimental animals. The rabbits were observed for three weeks. Each week, 6 experimental and 3 control animals were euthanized, their retina harvested and processed for light microscopy. Photomicrographs of the retina...
Tipo: Journal article
Palavras-chave: Monocular deprivation; Retina; Retinal Ganglion Cells; Dendritic features; Eye.
Ano: 2014
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022014000400004

Effects of Potentilla fulgens on the Changes Made in the Retinal Damage Induced by Traumatic Head Injury
Provedor de dados: 77
Autores: Hüseyin,Özevren; Engin,Deveci.
Traumatic head injury is a leading cause of mortality and morbidity. As a result of head trauma occurring in the retina of the various biochemical, histological and immunohistochemical effects were investigated. Sprague­Dawley rats were subjected to traumatic brain injury with a weight-drop device using 300 g-1 m weight­height impact. Twenty one rats were divided into three groups, as group 1 (vehicle-treated control), group 2 (vehicle-treated trauma) group 3 trauma + Potentilla fulgens ( P. Fulgens) 400 mg/kg/day, i.p.). Distilled water was used as vehicle. All rats were decapitated 5 days after the induction of trauma, and the protective effects of P. Fulgens were evaluated by histological, immunohistochemical and biochemical analyses. Although further...
Tipo: Journal article
Palavras-chave: Traumatic injury; Retina; Potentilla fulgens; Rat.
Ano: 2017
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022017000300007

Características Morfológicas de la Retina del Calderón Común (Globicephala melas; Traill, 1809) y su Relación con el Hábitat
Provedor de dados: 77
Autores: Mengual,R; Segovia,Y; García,M.
Existe una estrecha relación entre las características morfológicas de los sistemas sensoriales, su funcionamiento y el hábitat al que están adaptados los organismos. En este sentido, de todos los mamíferos marinos estudiados, los cetáceos son los que más profundamente han modificado su estructura y fisiología ocular por su estrecha adaptación a una vida exclusivamente acuática. Para aportar más datos a la literatura, el objetivo de este trabajo es describir morfológicamente la retina de la ballena piloto a través de técnicas de microscopia óptica, con el fin de relacionarla con su adaptación al medio acuático. Nuestros datos muestran que la retina de Globicephala melas se organiza de acuerdo al mismo plan básico de los vertebrados. Tiene un grosor medio...
Tipo: Journal article
Palavras-chave: Globicephala melas; Visión de cetáceos; Retina.
Ano: 2014
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022014000400044

Retinomotor movements in the Antarctic fish Trematomus newnesi Boulenger submitted to different environmental light conditions
Provedor de dados: 104
Autores: Donatti,Lucélia; Fanta,Edith.
The Antarctic fish Trematomus newnesi (Boulenger, 1902) occurs from benthic to pelagic habitats, in seasonally and daily varied photic conditions that induce retinomotor movements. Fish were experimentally kept under constant darkness or light, and 12Light/12Dark for seven days. The retinomotor movement of the pigment epithelium was established through the pigment index, while that of the cones was calculated as the length of the myoid. The retinomotor movement of the pigment epithelium in T.newnesi,revealed that the adaptation to constant light occurred in the one hour of exposure, remaining constant for the next seven days. However, the adaptation to constant darkness, was slower. The difference between the mean values of the pigment indices in the time...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Photic variation; Photoreceptors; Retina.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752007000200025

Morphology of the retina in the freshwater fish Metynnis roosevelti Eigenmann (Characidae, Serrasalminae) and the effects of monochromatic red light
Provedor de dados: 104
Autores: Donatti,Lucélia; Fanta,Edith.
The retina of Metynnis roosevelti Eigenmann, 1915, a very active freshwater fish, was investigated by light and electron microscopy and was found to have a complex neuronal structure that allows rapid responses of visual stimuli. Retina photoreceptors are double cones, single long cones, single short cones and rods. Cone inner segments are arranged as mosaics. The outer nuclear layer contains small nuclei of twin cones, long and wide nuclei of long single cones, spherical large nuclei of short cones, and small dense nuclei of rods. Horizontal, amacrine, bipolar and ganglion neurones are responsible for connections and integration between photoreceptor cells and afferent neurones. The pigmented epithelium comprises a single layer of cylindrical cells each...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fish; Retina; Morphology; Red light.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81751999000100011

EFECTO DE UN QUELANTE DE ZINC EXTRACELULAR SOBRE EL NÚMERO DE CÉLULAS GANGLIONARES EN RETINA DE RATA, Y TRANSPORTADORES DE TAURINA Y DE ZINC EN ESTAS CÉLULAS
Provedor de dados: 37
Autores: MÁRQUEZ GARCÍA,Asarí; SALAZAR,Víctor; LIMA,Lucimey.
RESUMEN La deficiencia de zinc en humanos produce disminución de antioxidantes, asociados a taurina, en la retina y se relaciona con adaptación anormal a la oscuridad, cataratas, ceguera y degeneración macular. Existe escasa evidencia acerca del efecto del zinc sobre el sistema de taurina en retina de mamíferos, por lo cual estudiamos el efecto del zinc sobre el transportador de taurina (TAUT) y los transportadores de zinc (ZnT-1 y 3) usando el quelante de zinc extracelular, ácido dietileno-triamino-penta-acético (DTPA), mediante inmunocitoquímica e inmunohistoquímica fluorescentes en células ganglionares (CG) y en las capas de la retina de ratas. Tres días después de la administración de DTPA (10μM) se utilizaron anticuerpos primarios y secundarios...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Retina; Taurina; Transportador de taurina; Transportadores de zinc; Zinc.
Ano: 2017
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2017000200002

COMPARACIÓN HISTOLÓGICA Y MORFOMÉTRICA ENTRE EL OJO DE Eremophilus mutisii (TRICHOMYCTERIDAE) Y EL DE Oncorhynchus mykiss (SALMONIDAE)
Provedor de dados: 37
Autores: TOVAR BOHÓRQUEZ,MARIO OSWALDO; CONTRERAS BRAVO,LUISA FERNANDA; CALDAS,MARIA LEONOR; RODRÍGUEZ CAICEDO,DANIEL; HURTADO GIRALDO,HERNÁN.
La visión es de importancia variable dependiendo de la relación de los peces con su hábitat, siendo clave en algunas especies y secundaria en otras. El objetivo de este estudio fue realizar una comparación entre el ojo de capitán de la sabana y trucha arco iris. La primera, nativa del altiplano cundiboyacence. La segunda es una especie introducida al país y con alta importancia en la piscicultura. Se obtuvieron cortes de ojo a 5 µm de espesor en ambas especies. Las dos presentan la estructura ocular típica de teleósteos conformada por una retina con ocho capas y dos membranas, células fotorreceptoras (conos y bastones), así como los otros tipos de células neuronales características (bipolares, horizontales, amacrinas y ganglionares), y un cristalino casi...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ojo; Retina; Morfometría; Trucha arco iris; Capitán de la sabana.
Ano: 2008
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2008000200005

Electroretinography in eight species of neotropical deer
Provedor de dados: 45
Autores: Crivelaro,R.M.; Thiesen,R.; Aldrovani,M.; Lima,T.B.; Ortêncio,K.P.; Padua,I.R.M.; Duarte,J.M.B.; Laus,J.L.
ABSTRACT The aim of this study was to establish normal baseline ERG values of 23 anesthetized deer belonging to 8 neotropical species (Mazama americana, Mazama nemorivaga, Mazama gouazoubira, Mazama nana, Mazama bororo, Ozotocerus bezoarticus, Odocoileus virginianus and Blastocerus dichotomus). Only right eyes were studied. Chemical restraint was performed using xylazine associated with ketamine, IM, for M. americana, M. gouazoubira, M. nemorivaga, M. nana, M. bororo, O. bezoarticus and O. virginianus. A combination of tiletamine/zolazepam diluted in xylazine 2% was used for B. dichotomus individuals. After 20min of dark adaptation, electroretinograms were obtained using a handheld electroretinography (ERG) machine using the QuickRetCheck Protocol at three...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cervidae; Habitat; Retina; Wild animal; ERG.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352018000501505

Avaliação da produção lacrimal, pressão intraocular, retinografia e biometria ocular em bovinos das raças Nelore e Gir hígidos
Provedor de dados: 45
Autores: Morais,T.L.; Neves,C.A.; Borges,N.C; Lima,A.M.V; Silva,L.F.L; Castro,L.T.S; Espindola,S.O; Cunha,P.H.J.
RESUMO No presente estudo, foram avaliados parâmetros oftalmológicos de 38 bovinos das raças Nelore (n= 19; grupo GN) e Gir (n= 19; grupo GG), machos, com idade média de 15 meses. Os exames oftalmológicos realizados foram teste lacrimal de Schirmer 1 (TLS-1), tonometria de aplanação, retinografia e biometria por ultrassonografia em modo B. Os resultados do TLS-1, tonometria de aplanação e biometria ocular foram avaliados por meio da análise de variância (ANOVA), e as médias comparadas pelo teste de Tukey. Para o exame de retinografia, foi realizada a análise descritiva das estruturas anatômicas. O TLS-1 e a tonometria não diferiram (P≥0,05) nas comparações entre os olhos e entre os grupos raciais. A retinografia permitiu a visualização do disco óptico, dos...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Oftalmologia; Retina; Schirmer; Tonometria; Ultrassonografia.
Ano: 2019
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352019000100177

A six-rhabdomere, open rhabdom arrangement in the eye of the chrysanthemum beetle Phytoecia rufiventris: some ecophysiological predictions based on eye anatomy
Provedor de dados: 47
Autores: Meyer-Rochow,Victor Benno; Mishra,Monalisa.
We are describing a rhabdom organization of the eye of the chrysanthemum beetle Phytoecia rufiventris that to date has not been described from any other insect. In cerambycid beetles free rhabdomeres, forming a circular, open rhabdom, surround a central rhabdom made up of the rhabdomeres of one or two cells. In Phytoecia rufiventris the central rhabdomeres are missing throughout the eye and the microvilli of the outer 6 rhabdomeres are regularly oriented in three directions. Following the classification of rhabdom types suggested by Wachmann (1979), we suggest to name the rhabdom arrangement seen in the retina of Phytoecia rufiventris "Grundmuster 3". This pattern ought to facilitate polarization sensitivity and movement perception, features that agree...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Compound eye; Retina; Vision; Polarization sensitivity.
Ano: 2009
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452009000200006

Microanatomical characteristics of marginal ommatidia in three different size-classes of the semi-terrestrial isopod Ligia exotica (Crustacea; Isopoda)
Provedor de dados: 47
Autores: Keskinen,Essi; Takaku,Yasuharu; Meyer-Rochow,Benno; Hariyama,Takahiko.
The aims of this paper have been (a) to characterize marginal ommatidia from different eyeregions through a detailed description of their distinct ultrastructural features in three different size-classes ofL. exotica, and (b) to compare microanatomical characteristics of the marginal ommatidia with those of ommatidia of the same eye, but located further centrally. On the basis of transverse as well as longitudinal sections we conclude that new ommatidia are added from a crescentic dorso-anterio-ventral edge of the eye and that maturing ommatidia go through a sequence in which originally the nuclei of cone -, pigment-, and retinula cells are arranged in three separate layers. At the beginning of the microvillar development, the organization of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Crustaceans; Eye; Retina; Vision; Growth; Moulting; Ultrastructure.
Ano: 2002
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452002000300006

The CK1 gene family: expression patterning in zebrafish development
Provedor de dados: 48
Autores: ALBORNOZ,AMELINA; YÁÑEZ,JOSÉ M; FOERSTER,CLAUDIA; AGUIRRE,CELESTE; PEREIRO,LUISA; BURZIO,VERÓNICA; MORAGA,MAURICIO; REYES,ARIEL E; ANTONELLI,MARCELO.
Protein kinase CK1 is a ser/thr protein kinase family which has been identified in the cytosol cell fraction, associated with membranes as well as in the nucleus. Several isoforms of this gene family have been described in various organisms: CK1á, CK1ß, CK1&amp;#948;, CK1å and CK1&amp;#947;. Over the last decade, several members of this family have been involved in development processes related to wnt and sonic hedgehog signalling pathways. However, there is no detailed temporal information on the CK1 family in embryonic stages, even though orthologous genes have been described in several different vertebrate species. In this study, we describe for the first time the cloning and detailed expression pattern of five CK1 zebrafish genes. Sequence analysis...
Tipo: Journal article
Palavras-chave: CK1; Casein Kinase 1; Expression pattern; Development; Zebrafish; Otic vesicles; Retina; Lens; Pectoral fin bud; Tegmentum; Myelencephalon; Telencephalon; Diencephalon; Mesencephalon; Rhombomeres.
Ano: 2007
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602007000200015

Feature Level Two -Dimensional Arrays Based Fusion in the Personal Authentication system using Physiological Biometric traits
Provedor de dados: 52
Autores: Carol .J,Jerusalin; Fred,A. Lenin; Daniel,Ashy.V.
ABSTRACT The fingerprint, knuckle print and the retina are used to authenticate a person accurately because of the permanence in the features. These three biometric traits are fused for better security. The fingerprint and knuckle print images are pre-processed by morphological techniques and the features are extracted from the normalized image using gabor filter. The retinal image is converted to gray image and pre-processing is done using top hat and bottom hat filtering. Blood vessels are segmented and the features are extracted by locating the optic disk as the centre point. The extracted features from the fingerprint, knuckle print and the retina are fused together as one template and stored in the data base for authentication purpose, thus reducing...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fingerprint; Knuckle print; Retina; Blood vessel segmentation; Feature level Fusion; Template.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132016000300408

Effects of mercury intoxication on the response of horizontal cells of the retina of thraira fish (Hoplias malabaricus)
Provedor de dados: 56
Autores: Tanan,C.L.; Ventura,D.F.; de Souza,J.M.; Grotzner,S.R.; Mela,M.; Gouveia Jr.,A.; Oliveira-Ribeiro,C.A.
Methyl mercury (MeHg) is highly neurotoxic, affecting visual function in addition to other central nervous system functions. The effect of mercury intoxication on the amplitude of horizontal cell responses to light was studied in the retina of the fish Hoplias malabaricus. Intracellular responses were recorded from horizontal cells of fish previously intoxicated with MeHg by intraperitoneal injection (IP group) or by trophic exposure (T group). Only one retina per fish was used. The doses of MeHg chloride administered to the IP group were 0.01, 0.05, 0.1, 1.0, 2.0, and 6.0 mg/kg. The amplitudes of the horizontal cell responses were lower than control in individuals exposed to 0.01 (N = 4 retinas), 0.05 (N = 2 retinas) and 0.1 mg/kg (N = 1 retina), whereas...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Methyl mercury; Horizontal cells; Electrophysiology; Hoplias malabaricus; Retina.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000700017

Caspase dependence of the death of neonatal retinal ganglion cells induced by axon damage and induction of autophagy as a survival mechanism
Provedor de dados: 56
Autores: Sternberg,C.; Benchimol,M.; Linden,R.
We examined the degeneration of post-mitotic ganglion cells in ex-vivo neonatal retinal explants following axon damage. Ultrastructural features of both apoptosis and autophagy were detected. Degenerating cells reacted with antibodies specific for activated caspase-3 or -9, consistent with the presence of caspase activity. Furthermore, peptidic inhibitors of caspase-9, -6 or -3 prevented cell death (100 µM Ac-LEDH-CHO, 50 µM Ac-VEID-CHO and 10 µM Z-DEVD-fmk, respectively). Interestingly, inhibition of autophagy by 7-10 mM 3-methyl-adenine increased the rate of cell death. Immunohistochemistry data, caspase activation and caspase inhibition data suggest that axotomy of neonatal retinal ganglion cells triggers the intrinsic apoptotic pathway, which, in turn,...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Apoptosis; Autophagy; Caspases; Retina; Central nervous system.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2010001000005

Effects of sciatic-conditioned medium on neonatal rat retinal cells in vitro
Provedor de dados: 56
Autores: Torres,P.M.M.; Guilarducci,C.V.V.; Araujo,E.G.
Schwann cells produce and release trophic factors that induce the regeneration and survival of neurons following lesions in the peripheral nerves. In the present study we examined the in vitro ability of developing rat retinal cells to respond to factors released from fragments of sciatic nerve. Treatment of neonatal rat retinal cells with sciatic-conditioned medium (SCM) for 48 h induced an increase of 92.5 ± 8.8% (N = 7 for each group) in the amount of total protein. SCM increased cell adhesion, neuronal survival and glial cell proliferation as evaluated by morphological criteria. This effect was completely blocked by 2.5 µM chelerythrine chloride, an inhibitor of protein kinase C (PKC). These data indicate that PKC activation is involved in the effect...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Cytokines; Neurotrophic factors; Retina; Schwann cells; Sciatic nerve.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998001100012

Modulation of the expression of the transcription factor Max in rat retinal ganglion cells by a recombinant adeno-associated viral vector
Provedor de dados: 56
Autores: Petrs-Silva,H.; Chiodo,V.; Chiarini,L.B.; Hauswirth,W.W.; Linden,R.
Exclusion of the transcription factor Max from the nucleus of retinal ganglion cells is an early, caspase-independent event of programmed cell death following damage to the optic axons. To test whether the loss of nuclear Max leads to a reduction in neuroprotection, we developed a procedure to overexpress Max protein in rat retinal tissue in vivo. A recombinant adeno-associated viral vector (rAAV) containing the max gene was constructed, and its efficiency was confirmed by transduction of HEK-293 cells. Retinal ganglion cells were accessed in vivo through intravitreal injections of the vector in rats. Overexpression of Max in ganglion cells was detected by immunohistochemistry at 2 weeks following rAAV injection. In retinal explants, the preparation of...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Retina; Max expression; Transcription factor; Viral vector; Gene therapy; Neuroprotection.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000300008

Evolution of circadian organization in vertebrates
Provedor de dados: 56
Circadian organization means the way in which the entire circadian system above the cellular level is put together physically and the principles and rules that determine the interactions among its component parts which produce overt rhythms of physiology and behavior. Understanding this organization and its evolution is of practical importance as well as of basic interest. The first major problem that we face is the difficulty of making sense of the apparently great diversity that we observe in circadian organization of diverse vertebrates. Some of this diversity falls neatly into place along phylogenetic lines leading to firm generalizations: i) in all vertebrates there is a "circadian axis" consisting of the retinas, the pineal gland and the...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Circadian rhythms; Evolution; Vertebrates; Pineal; SCN; Retina; Melatonin.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000300003

Evidence of muscarinic acetylcholine receptors in the retinal centrifugal system of the chick
Provedor de dados: 56
Autores: Calaza,K.C.; Gardino,P.F.
In this study we characterize the presence of muscarinic acetylcholine receptors (mAChR) in the isthmo-optic nucleus (ION) of chicks by immunohistochemistry with the M35 antibody. Some M35-immunoreactive fibers were observed emerging from the retinal optic nerve insertion, suggesting that they could be centrifugal fibers. Indeed, intraocular injections of cholera toxin B (CTb), a retrograde tracer, and double-labeling with M35 and CTb in the ION confirmed this hypothesis. The presence of M35-immunoreactive cells and the possible mAChR expression in ION and ectopic neuron cells in the chick brain strongly suggest the existence of such a cholinergic system in this nucleus and that acetylcholine release from amacrine cells may mediate interactions between...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Muscarinic receptors; Retina; Isthmo-optic nucleus; Centrifugal fibers; Acetylcholine; Chick.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2000000900014

Veratridine increases the survival of retinal ganglion cells in vitro
Provedor de dados: 56
Autores: Pereira,S.P.F.; Araujo,E.G.
Neuronal cell death is an important phenomenon involving many biochemical pathways. This degenerative event has been studied to understand how the cells activate the mechanisms that lead to self-destruction. Target cells and afferent cells play a relevant role in the regulation of natural cell death. We studied the effect of veratridine (1.5, 3.0, 4.5 and 6.0 µM) on the survival of neonatal rat retinal ganglion cells in vitro. Veratridine (3.0 µM), a well-known depolarizing agent that opens the Na+ channel, promoted a two-fold increase in the survival of retinal ganglion cells kept in culture for 48 h. This effect was dose-dependent and was blocked by 1.0 µM tetrodotoxin (a classical voltage-dependent Na+ channel blocker) and 30.0 µM flunarizine (a Na+ and...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Veratridine; Retinal ganglion cells; Natural cell death; Development; Retina.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001200014

Retinal protective effects of topically administered agmatine on ischemic ocular injury caused by transient occlusion of the ophthalmic artery
Provedor de dados: 56
Autores: Hong,S.; Hara,H.; Shimazawa,M.; Hyakkoku,K.; Kim,C.Y.; Seong,G.J.
Agmatine, an endogenous polyamine and putative neuromodulator, is known to have neuroprotective effects on various neurons in the central nervous system. We determined whether or not topically administered agmatine could reduce ischemic retinal injury. Transient ocular ischemia was achieved by intraluminal occlusion of the middle cerebral artery of ddY mice (30-35 g) for 2 h, which is known to also induce occlusion of the ophthalmic artery. In the agmatine group (N = 6), a 1.0 mM agmatine-containing ophthalmic solution was administered four times daily for 2 weeks before occlusion. In the control group (N = 6), a 0.1% hyaluronic acid ophthalmic solution was instilled at the same times. At 22 h after reperfusion, the eyeballs were enucleated and the retinal...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Agmatine; Apoptosis; Ischemia; Neuroprotection; Retina.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000300005

Inhibition of carbachol-induced inositol phosphate accumulation in the embryonic retina promoted by kainate and veratridine
Provedor de dados: 56
Autores: Sanches,G.; Ventura,A.L.M.
In the present study, we report that low concentrations of the glutamate ionotropic agonist kainate decreased the turnover of [3H]-phosphoinositides ([3H]-InsPs) induced by muscarinic receptors in the chick embryonic retina. When 100 µM carbachol was used, the estimated IC50 value for kainate was 0.2 µM and the maximal inhibition of ~50% was obtained with 1 µM or higher concentrations of the glutamatergic agonist. Our data also show that veratridine, a neurotoxin that increases the permeability of voltage-sensitive sodium channels, had no effect on [3H]-InsPs levels of the embryonic retina. However, 50 µM veratridine, but not 50 mM KCl, inhibited ~65% of the retinal response to carbachol. While carbachol increased [3H]-InsPs levels from 241.2 ± 38.0 to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Muscarinic receptors; Phosphoinositides; Kainate; Sodium channels; Retina.
Ano: 1998
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1998000700009

Nuclear exclusion of transcription factors associated with apoptosis in developing nervous tissue
Provedor de dados: 56
Autores: Linden,R.; Chiarini,L.B.
Programmed cell death in the form of apoptosis involves a network of metabolic events and may be triggered by a variety of stimuli in distinct cells. The nervous system contains several neuron and glial cell types, and developmental events are strongly dependent on selective cell interactions. Retinal explants have been used as a model to investigate apoptosis in nervous tissue. This preparation maintains the structural complexity and cell interactions similar to the retina in situ, and contains cells in all stages of development. We review the finding of nuclear exclusion of several transcription factors during apoptosis in retinal cells. The data reviewed in this paper suggest a link between apoptosis and a failure in the nucleo-cytoplasmic partition of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Programmed cell death; Retina; Neurogenesis; Development; Nuclear membrane.
Ano: 1999
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1999000700003

Electroretinography in dogs using a fiber electrode prototype
Provedor de dados: 56
Autores: Pereira,A.L.; Montiani-Ferreira,F.; Santos,V.R.; Salomão,S.R.; Souza,C.; Berezovsky,A.
We compared two electroretinography (ERG) electrodes in dogs using ERG standards of the International Society for Clinical Electrophysiology of Vision (ISCEV). Ten healthy Yorkshire terrier dogs (mean age, 2.80 ± 1.42 years; 6 females) weighing 5.20 ± 1.56 kg were evaluated using an ERG system for veterinary use. Dark- and light-adapted ERG responses were recorded using an ERG-Jet electrode and a fiber electrode prototype. The examinations were performed during 2 visits, 3 weeks apart. Both electrodes (ERG-Jet or fiber prototype) were used on each animal and the first eye to be recorded (OD × OS) was selected randomly. Three weeks later the examination was repeated on the same animal switching the type of electrode to be used that day and the first eye to...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Electroretinography; Electrode; Retina; Canine; Prototype.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2013000300257

Influence of melatonin on the development of functional nicotinic acetylcholine receptors in cultured chick retinal cells
Provedor de dados: 56
Autores: Sampaio,L.F.S.; Hamassaki-Britto,D.E.; Markus,R.P.
The influence of melatonin on the developmental pattern of functional nicotinic acetylcholine receptors was investigated in embryonic 8-day-old chick retinal cells in culture. The functional response to acetylcholine was measured in cultured retina cells by microphysiometry. The maximal functional response to acetylcholine increased 2.7 times between the 4th and 5th day in vitro (DIV4, DIV5), while the Bmax value for [125I]-alpha-bungarotoxin was reduced. Despite the presence of alpha8-like immunoreactivity at DIV4, functional responses mediated by alpha-bungarotoxin-sensitive nicotinic acetylcholine receptors were observed only at DIV5. Mecamylamine (100 µM) was essentially without effect at DIV4 and DIV5, while dihydro-ß-erythroidine (10-100 µM) blocked...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Retina; Development; Nicotinic acetylcholine receptors; Alpha-bungarotoxin; Melatonin; Microphysiometry.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000400015

Pupil size following dark adaptation in patients with retinitis pigmentosa
Provedor de dados: 56
Autores: Berezovsky,A.; Salomão,S.R.; Birch,D.G.
According to the equivalent light hypothesis, molecular defects in the photoreceptor lead to a continuous activation of the photoreceptor cascade in a manner equivalent to real light. The consequences in diseases such as retinitis pigmentosa (RP) are as disruptive to the cells as real light. Two forms of the equivalent light hypothesis can be distinguished: strong - mutations in rhodopsin or other cascade proteins in some forms of RP continuously excite the visual phototransduction cascade; weak - disruption of outer segments in all patients with RP eliminates circulating dark current and blocks neurotransmitter release in a manner similar to real light. Both forms of the equivalent light hypothesis predict that pupils of patients with RP will be...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Pupil; Retina; Retinitis pigmentosa.
Ano: 2001
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2001000800010

Losses of immunoreactive parvalbumin amacrine and immunoreactive alphaprotein kinase C bipolar cells caused by methylmercury chloride intoxication in the retina of the tropical fish Hoplias malabaricus
Provedor de dados: 56
Autores: Bonci,D.M.O.; Lima,S.M.A. de; Grötzner,S.R.; Oliveira Ribeiro,C.A.; Hamassaki,D.E.; Ventura,D.F.
To quantify the effects of methylmercury (MeHg) on amacrine and on ON-bipolar cells in the retina, experiments were performed in MeHg-exposed groups of adult trahiras (Hoplias malabaricus) at two dose levels (2 and 6 µg/g, ip). The retinas of test and control groups were processed by mouse anti-parvalbumin and rabbit anti-alphaprotein kinase C (alphaPKC) immunocytochemistry. Morphology and soma location in the inner nuclear layer were used to identify immunoreactive parvalbumin (PV-IR) and alphaPKC (alphaPKC-IR) in wholemount preparations. Cell density, topography and isodensity maps were estimated using confocal images. PV-IR was detected in amacrine cells in the inner nuclear layer and in displaced amacrine cells from the ganglion cell layer, and...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Methylmercury; Retina; Hoplias malabaricus; Amacrine cells; Displaced amacrine cells; ON-bipolar cells.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000300011

Conditioned medium from activated spleen cells supports the survival of rat retinal cells in vitro
Provedor de dados: 56
Autores: Sholl-Franco,A.; Araujo,E.G.
Cytokines are a heterogeneous group of molecules that have been associated with several functions in the nervous system, such as survival and differentiation of neuronal and glial cells. In the present study, we demonstrated that conditioned medium from spleen cells activated with concanavalin A increased neuritogenesis and survival of retinal cells, as measured by biochemical and morphological criteria. Our data showed that conditioned medium induced a five-fold increase in the amount of protein after 120 h in vitro. This effect was not inhibited by the blockade of voltage-dependent L-type calcium channels with 5.0 µM nifedipine. However, the use of an intracellular calcium chelator (15.0 µM BAPTA-AM) inhibited this effect. Our results support the idea...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cytokines; Growth factor; Neuroimmunology; Retina; Development.
Ano: 1997
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997001100006

Can the fractal dimension be applied for the early diagnosis of non-proliferative diabetic retinopathy?
Provedor de dados: 56
Autores: Kunicki,A.C.B.; Oliveira,A.J.; Mendonça,M.B.M.; Barbosa,C.T.F.; Nogueira,R.A.
The fractal dimension has been employed as a useful parameter in the diagnosis of retinal disease. Avakian et al. (Curr Eye Res 2002; 24: 274-280), comparing the vascular pattern of normal patients with mild to moderate non-proliferative diabetic retinopathy (NPDR), found a significant difference between them only in the macular region. This significant difference in the box-counting fractal dimension of the macular region between normal and mild NPDR patients has been proposed as a method of precocious diagnosis of NPDR. The aim of the present study was to determine if fractal dimensions can really be used as a parameter for the early diagnosis of NPDR. Box-counting and information fractal dimensions were used to parameterize the vascular pattern of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Box-counting; Fractal dimension; Information fractal dimension; Retina; Vascularization; Non-proliferative diabetic retinopathy.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2009001000009

Synaptic vesicle cycling is not impaired in a glutamatergic and a cholinergic synapse that exhibit deficits in acidification and filling
Provedor de dados: 60
Autores: Abreu,Bento João; Leite,Luciana Ferreira; Oliveira,Débora Lopes; Amaral,Ernani.
The purpose of the present work was to investigate synaptic vesicle trafficking when vesicles exhibit alterations in filling and acidification in two different synapses: a cholinergic frog neuromuscular junction and a glutamatergic ribbon-type nerve terminal in the retina. These synapses display remarkable structural and functional differences, and the mechanisms regulating synaptic vesicle cycling might also differ between them. The lipophilic styryl dye FM1-43 was used to monitor vesicle trafficking. Both preparations were exposed to pharmacological agents that collapse ΔpH (NH4Cl and methylamine) or the whole ΔµH+ (bafilomycin), a necessary situation to provide the driving force for neurotransmitter accumulation into synaptic vesicles. The results...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Synaptic vesicle; Acidification; Lipophilic styryl dye/use; Neuromuscular junction; Bipolar cell; Retina.
Ano: 2012
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502012000100017

The organization of flash electroretinography unit in Veterinary Medicine
Provedor de dados: 65
Autores: Honsho,Cristiane dos Santos; Oriá,Arianne Pontes; Lazaro Júnior,Luiz Paulo da Veiga Monteiro; Dorea Neto,Francisco; Laus,José Luiz.
Electroretinography is the technique that allows the evaluation of changes in electrical potential that occur when the eye is stimulated by light. Such changes reflect the response of several retinal cells including photoreceptors (cones and rods). Thus it evaluates the retinal functionality and can diagnose abnormalities in retinas seem to be normal by ophthalmoscopy. Due to the constant evolution in veterinary ophthalmology, new centers of retinal electrophysiology have been introduced around the world either for early diagnosis of retinopathies or for preoperative evaluation of animals with cataracts and glaucoma, as well as for continuing research. The Ophthalmology Unit of the "Governador Laudo Natel" Veterinary Teaching Hospital, in the Faculty of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Electroretinography; Retina; Electrophysiology; Dogs.
Ano: 2004
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782004000400021

Atrofia progressiva generalizada da retina em cães da raça Cocker Spaniel
Provedor de dados: 65
Autores: Gomes,Débora; Otsuki,Denise Aya; Lisak,Ricardo; Safatle,Angélica de Mendonça Vaz.
Atrofia progressiva generalizada da retina (APGR) é uma doença frequente nos cães da raça Cocker Spaniel, caracterizada pela perda progressiva da função retiniana externa e desaparecimento dos fotorreceptores. A doença é bilateral, hereditária, autossômica recessiva, sem predisposição sexual e está frequentemente associada à catarata. Segundo estudos moleculares, a degeneração ocorre por mutação de diversos genes. Nos cães da raça Cocker Spaniel Americano, a doença é observada entre três e cinco anos de idade e, no Cocker Spaniel Inglês, entre quatro e oito anos de idade. Os sinais clínicos mais encontrados são: nictalopia, hiperreflexia tapetal e catarata. O diagnóstico baseia-se no histórico clínico, exame oftalmológico e em exames complementares, como...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Retina; Cocker Spaniel; Catarata; Degeneração retiniana.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782013000800011