Studies demonstrate localized neuro-retinal dysfunction in patients with diabetes and no visible diabetic retinopathy (DR). Poor glycemic control is a strong risk factor for DR. We hypothesized that poor glycemic control predicts increased areas of localized neuro-retinal dysfunction in patients with diabetes. Forty-eight adolescents with diabetes and 45 controls were tested using the standard (103 hexagons) multifocal electroretinogram (mfERG). Negative binomial regression analysis was conducted with number of abnormal hexagons (delayed responses) as the dependent variable and glycated hemoglobin (HbA1c), disease duration, age and sex as covariates. Results indicate that a one-unit increase in HbA1c predicts an 80% (p = 0.002) increase in the number of abnormal hexagons when controlling for age. Increased areas of neuro-retinal dysfunction are predicted by worsening glycemic control in patients with no visible DR. Standard mfERG may be useful in monitoring patients with diabetes and identifying those who may be at risk of developing DR.

This study investigated whether lutein and DHA enriched egg consumption can improve electrophysiological retina function for the prevention of age-related macular degeneration in Caucasian older adults. Thirty (male: n=11, female: n=19) healthy Caucasian older adults (64.0 ± 3.4 years) consumed two lutein and DHA enriched eggs (0.87 mg lutein/day, 220 mg DHA/day) daily for six weeks. Retina function, plasma and red blood cell (RBC) DHA, plasma lutein, lipid profiles, and lipoprotein subfractions were assessed at day 0 and 6 wks. The maximum amplitude of scotopic a-wave and photopic b-wave significantly increased along with plasma DHA concentrations No significant alterations in plasma Chol, HDL-Chol, LDL-Chol, triacylglycerides, plasma lutein and RBC DHA were present. A significant increase in large HDL particles and a decrease in intermediate sized HDL particles occurred. This study suggests that consuming two lutein and DHA enriched eggs daily may improve electrophysiological retina function without adversely altering plasma lipids in Caucasian older adults. / May 2017

Diabete melito (DM) é uma doença freqüente, complexa e multifatorial, caracterizada pela ausência absoluta ou relativa de insulina, correspondendo a uma das principais endocrinopatias no cão. Freqüentemente, o cão diabético é acometido por catarata, resultando em cegueira e impossibilitando a oftalmoscopia, diferentemente do homem, no qual a oftalmoscopia permite diagnosticar, estadiar e tratar a retinopatia diabética (RD) que é uma microangiopatia que afeta primariamente as arteríolas précapilares, capilares, vênulas pós-capilares e vasos de maior calibre. Na presença de opacidade densa de meios, a avaliação da função retiniana pode ser feita com o Eletrorretinograma de Campo Total (ERG) que é o traçado obtido da resposta elétrica produzida pela retina, em conseqüência à estimulação luminosa, fornecendo dados objetivos. O presente estudo objetivou avaliar as alterações eletrorretinográficas em cães diabéticos portadores de catarata madura ou hipermadura, seguindo o protocolo da International Society for Clinical Electrophysiology of Vision (ISCEV), avaliando a prevalência e a gravidade da retinopatia diabética nesta espécie. Foram realizados exames em 74 cães (53 fêmeas e 21 machos), de 6 a 13 anos de idade (média 9,4 anos), provenientes do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo divididos em 3 grupos: GN (grupo normal) - cães normais; GC (grupo catarata) - cães com catarata (madura e hipermadura); GD (grupo diabete melito) - cães com catarata e com DM. Nos três grupos, foram mensurados a amplitude pico a pico em microvolts (&micro;V) e o tempo de culminação da onda-b em milisegundos (ms). Observou-se tendência de queda nas amplitudes das respostas no grupo dos animais diabéticos (GD), quando comparado com os grupos GN e GC. Esta redução foi estatisticamente significante (p< 0,05) na amplitude dos bastonetes e nos potenciais oscilatórios quando se comparou GN com GD (61,4&micro;V versus 46,7&micro;V; 9,8&micro;V versus 6,2&micro;V, respectivamente); e na amplitude do Flicker quando se comparou GN com GC (14,1&micro;V versus 9,2&micro;V) e GN com GD (14,1 versus 5,9&micro;V). Houve aumento (atraso) do tempo de culminação da onda-b nos grupos GC e GD comparado com GN. Esta diferença foi estatisticamente significante quando se comparou GN com GC (48,3ms versus 54,0ms) e GN com GD na resposta de bastonetes (48,3ms versus 55,8ms), máxima resposta (29,6ms versus 33,0ms), resposta de cones (29,0ms versus 31,5ms) e Flicker. (21,6ms versus 24,4ms). Com estes dados, pode-se sugerir que estes cães portadores de DM apresentaram retinopatia diabética. / Diabetes mellitus (DM) is a common, complex and multifactorial disease characterized by absolute and/or relative absence of insulin, composing one of the most important dog\'s endocrinopathies. Diabetic dogs are frequently affected by cataracts, resulting in blindness and impossibility to visualize the fundus, in contrast to the humans in whom the ophthamoscopic examination allows the diagnosis, staging and treatment of the diabetic retinopathy (DR). The DR is a microangiopathy that affects specially the pre-capillary arterioles, capillaries, post-capillary venulas and large vessels. In the presence of dense opacity of the lens, the retina function may be evaluated with Full Field Electroretinography (ERG), which is the trace obtained from the retina electric response due to the luminous stimulation resulting in objective data. The aim of this study was to evaluate the electroretinographic alterations in diabetic dogs with mature or hypermature cataracts, following the International Society for Clinical Electrophysiology of Vision (ISCEV) protocol. Thus, the prevalence and the severity of the diabetic retinopathy were evaluated in this specie. ERG examinations were performed in seventy-four dogs, from 6 to 13 years old (medium 9.4 years old). Fifty-three were females and 21 males, from the Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. The animals were divided in three groups: Group N (GN) - normal dogs; Group C (GC) - dogs with cataracts (mature and hypermature); Group D (GD) - dogs with cataracts and DM. The peak to peak amplitude in microvolts (&micro;V) and the b-wave implicity time in milliseconds (ms) were measured. There was a decrease in amplitude of the responses in diabetic animals, compared to groups N and C. This reduction was statistically significant (p< 0.05) in rod amplitude and POs when compared GN with GD (61.4&micro;V versus 46.7&micro;V; 9.8&micro;V versus 6.2&micro;V, respectively); and Flicker amplitude when compared GN with GC (14.1&micro;V versus 9.2&micro;V) and GN with GD (14.1 versus 5.9&micro;V). There was an augmentation of the implicity time in the diabetic animals, compared to groups GN and GC. This difference was statistically significant when compared GN with GC in rod response (48.3ms versus 54.0ms) and GN with GD in rod response (48.3ms versus 55.8ms), maximum response (29.6ms versus 33.0ms), cone response (29.0ms versus 31.5ms) and Flicker (21.6ms versus 24.4ms). Based on these data from ERG exam, it can be suggested that these diabetic dogs presented diabetic retinopathy.

O eletrorretinograma de campo total consiste no registro da resposta elétrica difusa gerada pelas células da retina, e é considerado, nos cães, um exame essencial, principalmente nos casos de encaminhamento de cirurgia de catarata e em doenças que afetam a função retiniana. Todavia, diversos fatores podem influenciar nos valores de amplitude e tempo de culminação das respostas obtidas no exame, como idade do animal, raça, presença de catarata e seu estágio de desenvolvimento e uso da anestesia ou sedação. O objetivo desse estudo foi avaliar a interferência da idade e do estágio de desenvolvimento da catarata, além de padronizar valores da resposta dos eletrorretinogramas, nos cães da raça Yorkshire Terrier, com uso de sedação. Foram selecionadas 84 fichas e 157 olhos de exames realizados no período de 2006 a 2013. Utilizou-se aparelho de eletrorretinograma de campo total BMP-200 e eletrodo ativo corneal ERG-jet. Amplitude de pico a pico e tempo de culminação de resposta de bastonetes, máxima e cones foram obtidas. Os animais foram separados de acordo com as faixas etárias:1 a 5 anos de idade, 6 a 10 anos de idade e 11 a 15 anos de idade. Adicionalmente, os olhos selecionados foram divididos pelo estágio de desenvolvimento da catarata apresentada: incipiente, imatura, madura e hipermadura. Testes ANOVA de duas vias foram realizados para determinar possível diferença entre os grupos de tipos de catarata e entre as faixas etárias. Os valores padrão de cada grupo foi descrito. Houve diferença na amplitude da resposta de bastonetes, máxima e cones entre todas as faixas etárias, além de diferença no tempo de culminação da resposta máxima entre as faixas etárias. O aumento da idade do animal mostrou-se como o fator mais influente nos valores de amplitude de bastonetes, máxima e cones. O tempo de culminação, no entanto, mostrou-se mais estável. Os diferentes estágios de desenvolvimento de catarata apresentaram pouca interferência na resposta final do eletrorretinograma. Conclui-se que a idade é o principal fator de interferência do eletrorretinograma de campo total nos cães, nos valores de amplitude pico a pico, nas respostas de bastonetes, máxima e cones. A presença de catarata e seu estágio de desenvolvimento não foram significativos / Full field electroretinogram is the record of a diffuse electrical response generated by the cells in the retina and is considered, in dogs, fundamental in cataract cases prior to surgery and retinal function affecting diseases. There are several aspects, however, that may influence amplitude and implicit time values of the exam, such as age, breed, cataract existence and stage of cataract development and anesthesia or sedation protocol. The aim of this study was to assess age and stage of cataract development interference and, additionally, standardize electroretinogram values in Yorkshire Terrier dogs using sedation. 84 records and 157 eyes were selected from 2006 to 2013 period. The BMP-200 full field electroretinogram system was used along with corneal active ERG-Jet contact lens electrode. Amplitude and implicit time values of rods, mixed rod-cone and cones were obtained. All animals were separated according the following age group: 1 to 5 years old, 6 to 10 years old and 11 to 15 years old. Additionally, the selected eyes were separated by cataract development stage, such as: incipient, immature, mature and hypermature cataract. Two-way ANOVA tests were performed to determine possible difference between cataract stage groups and age groups. Standardize values of each group was reported. There was difference in amplitude values response of rod, mixed rod-cones and cones amplitude in all age groups, in addition to difference in implicit time values of mixed rod-cones in all age groups. Animal age progression was found as the most influent factor in rod, mixed rod-cones and cones amplitude values. Implicit time values, however, exhibit a more stable response values. Cataract stage development was not substantial in influence amplitude values of rod, mixed rodcones and cone final electroretinogram responses. This study has shown that age is the main factor of full field electroretinogram interference in amplitude values response of rod, mixed rod-cones and cones in dogs. The presence of cataract and the development stage were not relevant

Sexual selection and the maintenance of species diversity in Lake Malawi cichlid fishes are greatly dependent on optical communication, which is influenced by environmental, physiological and endocrinological factors. The diversity in spectral sensitivity of cichlids has been partially attributed to differences in opsin gene expression, with each species preferentially expressing a subset of seven possible genes. Hormones such as gonadotropin releasing hormone (GnRH) can mediate changes in gene expression and the presence of GnRH immunoreactive fibers and GnRH receptors throughout the retinal layers make it an excellent candidate for mediating changes in visual processes. Effects of exogenous GnRH administration on the visual system of zebra cichlids (Metriaclima zebra) via prolonged release cholesterol implants and intubation was investigated using electroretinogram (ERG) recordings, quantitative real-time RT-PCR and in situ hybridization. Three week and ten week sampling periods were used in the intubation study. No obvious differences in spectral sensitivity were evident when looking at a-wave, b-wave and d-wave components of the ERG waveform in any of the treatment groups. A multiple mechanism model was used to describe the cone mechanisms mediating spectral sensitivity and this analysis showed that the activity of cones was shaped by opponent and non opponent cone interactions based on subsets of five opsin genes previously described in cichlids (SWS1, SWS2b, RH2b, RH2aβ, and RH2aα). Although differences in the spectral sensitivity between control and GnRH-treated fish were not evident on a functional level, there were changes in the gonadosomatic index in the intubation group. Quantitative real-time RT-PCR (qRT-PCR) and in situ hybridization demonstrated that treatment with a synthetic GnRH3 analogue using the oral intubation delivery system resulted in statistically significant changes in opsin gene expression in both three week and ten week treatment groups, specifically the upregulation of RH2b and the downregulation of RH2a opsin genes. Moreover, in situ hybridization analysis showed that the pattern of labeling for the RH2a and RH2b riboprobes corroborated the changes in opsin gene expression found in the qRT-PCR data. In contrast, GnRH treatment using the cholesterol implant delivery system did not result in significant changes in spectral sensitivity or opsin gene expression. / Thesis (Master, Biology) -- Queen's University, 2011-01-05 22:57:11.308

Carotenoids are essential for visual function, however their potential role in Computer Vision Syndrome (CVS) is not known. By providing carrot powder, this study examined carotenoid metabolism and visual function in CVS. CVS participants were recruited into a double-blind, placebo-controlled, repeated measures trial (n=19, ages 20-65) and were randomized to 2 supplementation groups; control (15g cream of wheat powder) or carrot enriched (15g carrot powder, 33% of vitamin A RDA for adults) in an isocaloric pudding and yogurt for 4 weeks. Retinal function, self-perceived vision status, and plasma carotenoids/retinoids were assessed, along with plasma lipids and oxidative stress markers. Photopic b-waves marginally improved following supplementation reflecting higher phototransduction, possibly due to increased plasma carotenoid/retinoid levels. LDL cholesterol and oxidative stress markers showed trending reductions illustrating a protective role of the carrot. Carrot powder, at a minimal supplementation dose, can be recommended for CVS.

Diabete melito (DM) é uma doença freqüente, complexa e multifatorial, caracterizada pela ausência absoluta ou relativa de insulina, correspondendo a uma das principais endocrinopatias no cão. Freqüentemente, o cão diabético é acometido por catarata, resultando em cegueira e impossibilitando a oftalmoscopia, diferentemente do homem, no qual a oftalmoscopia permite diagnosticar, estadiar e tratar a retinopatia diabética (RD) que é uma microangiopatia que afeta primariamente as arteríolas précapilares, capilares, vênulas pós-capilares e vasos de maior calibre. Na presença de opacidade densa de meios, a avaliação da função retiniana pode ser feita com o Eletrorretinograma de Campo Total (ERG) que é o traçado obtido da resposta elétrica produzida pela retina, em conseqüência à estimulação luminosa, fornecendo dados objetivos. O presente estudo objetivou avaliar as alterações eletrorretinográficas em cães diabéticos portadores de catarata madura ou hipermadura, seguindo o protocolo da International Society for Clinical Electrophysiology of Vision (ISCEV), avaliando a prevalência e a gravidade da retinopatia diabética nesta espécie. Foram realizados exames em 74 cães (53 fêmeas e 21 machos), de 6 a 13 anos de idade (média 9,4 anos), provenientes do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo divididos em 3 grupos: GN (grupo normal) - cães normais; GC (grupo catarata) - cães com catarata (madura e hipermadura); GD (grupo diabete melito) - cães com catarata e com DM. Nos três grupos, foram mensurados a amplitude pico a pico em microvolts (&micro;V) e o tempo de culminação da onda-b em milisegundos (ms). Observou-se tendência de queda nas amplitudes das respostas no grupo dos animais diabéticos (GD), quando comparado com os grupos GN e GC. Esta redução foi estatisticamente significante (p< 0,05) na amplitude dos bastonetes e nos potenciais oscilatórios quando se comparou GN com GD (61,4&micro;V versus 46,7&micro;V; 9,8&micro;V versus 6,2&micro;V, respectivamente); e na amplitude do Flicker quando se comparou GN com GC (14,1&micro;V versus 9,2&micro;V) e GN com GD (14,1 versus 5,9&micro;V). Houve aumento (atraso) do tempo de culminação da onda-b nos grupos GC e GD comparado com GN. Esta diferença foi estatisticamente significante quando se comparou GN com GC (48,3ms versus 54,0ms) e GN com GD na resposta de bastonetes (48,3ms versus 55,8ms), máxima resposta (29,6ms versus 33,0ms), resposta de cones (29,0ms versus 31,5ms) e Flicker. (21,6ms versus 24,4ms). Com estes dados, pode-se sugerir que estes cães portadores de DM apresentaram retinopatia diabética. / Diabetes mellitus (DM) is a common, complex and multifactorial disease characterized by absolute and/or relative absence of insulin, composing one of the most important dog\'s endocrinopathies. Diabetic dogs are frequently affected by cataracts, resulting in blindness and impossibility to visualize the fundus, in contrast to the humans in whom the ophthamoscopic examination allows the diagnosis, staging and treatment of the diabetic retinopathy (DR). The DR is a microangiopathy that affects specially the pre-capillary arterioles, capillaries, post-capillary venulas and large vessels. In the presence of dense opacity of the lens, the retina function may be evaluated with Full Field Electroretinography (ERG), which is the trace obtained from the retina electric response due to the luminous stimulation resulting in objective data. The aim of this study was to evaluate the electroretinographic alterations in diabetic dogs with mature or hypermature cataracts, following the International Society for Clinical Electrophysiology of Vision (ISCEV) protocol. Thus, the prevalence and the severity of the diabetic retinopathy were evaluated in this specie. ERG examinations were performed in seventy-four dogs, from 6 to 13 years old (medium 9.4 years old). Fifty-three were females and 21 males, from the Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo. The animals were divided in three groups: Group N (GN) - normal dogs; Group C (GC) - dogs with cataracts (mature and hypermature); Group D (GD) - dogs with cataracts and DM. The peak to peak amplitude in microvolts (&micro;V) and the b-wave implicity time in milliseconds (ms) were measured. There was a decrease in amplitude of the responses in diabetic animals, compared to groups N and C. This reduction was statistically significant (p< 0.05) in rod amplitude and POs when compared GN with GD (61.4&micro;V versus 46.7&micro;V; 9.8&micro;V versus 6.2&micro;V, respectively); and Flicker amplitude when compared GN with GC (14.1&micro;V versus 9.2&micro;V) and GN with GD (14.1 versus 5.9&micro;V). There was an augmentation of the implicity time in the diabetic animals, compared to groups GN and GC. This difference was statistically significant when compared GN with GC in rod response (48.3ms versus 54.0ms) and GN with GD in rod response (48.3ms versus 55.8ms), maximum response (29.6ms versus 33.0ms), cone response (29.0ms versus 31.5ms) and Flicker (21.6ms versus 24.4ms). Based on these data from ERG exam, it can be suggested that these diabetic dogs presented diabetic retinopathy.

O eletrorretinograma de campo total consiste no registro da resposta elétrica difusa gerada pelas células da retina, e é considerado, nos cães, um exame essencial, principalmente nos casos de encaminhamento de cirurgia de catarata e em doenças que afetam a função retiniana. Todavia, diversos fatores podem influenciar nos valores de amplitude e tempo de culminação das respostas obtidas no exame, como idade do animal, raça, presença de catarata e seu estágio de desenvolvimento e uso da anestesia ou sedação. O objetivo desse estudo foi avaliar a interferência da idade e do estágio de desenvolvimento da catarata, além de padronizar valores da resposta dos eletrorretinogramas, nos cães da raça Yorkshire Terrier, com uso de sedação. Foram selecionadas 84 fichas e 157 olhos de exames realizados no período de 2006 a 2013. Utilizou-se aparelho de eletrorretinograma de campo total BMP-200 e eletrodo ativo corneal ERG-jet. Amplitude de pico a pico e tempo de culminação de resposta de bastonetes, máxima e cones foram obtidas. Os animais foram separados de acordo com as faixas etárias:1 a 5 anos de idade, 6 a 10 anos de idade e 11 a 15 anos de idade. Adicionalmente, os olhos selecionados foram divididos pelo estágio de desenvolvimento da catarata apresentada: incipiente, imatura, madura e hipermadura. Testes ANOVA de duas vias foram realizados para determinar possível diferença entre os grupos de tipos de catarata e entre as faixas etárias. Os valores padrão de cada grupo foi descrito. Houve diferença na amplitude da resposta de bastonetes, máxima e cones entre todas as faixas etárias, além de diferença no tempo de culminação da resposta máxima entre as faixas etárias. O aumento da idade do animal mostrou-se como o fator mais influente nos valores de amplitude de bastonetes, máxima e cones. O tempo de culminação, no entanto, mostrou-se mais estável. Os diferentes estágios de desenvolvimento de catarata apresentaram pouca interferência na resposta final do eletrorretinograma. Conclui-se que a idade é o principal fator de interferência do eletrorretinograma de campo total nos cães, nos valores de amplitude pico a pico, nas respostas de bastonetes, máxima e cones. A presença de catarata e seu estágio de desenvolvimento não foram significativos / Full field electroretinogram is the record of a diffuse electrical response generated by the cells in the retina and is considered, in dogs, fundamental in cataract cases prior to surgery and retinal function affecting diseases. There are several aspects, however, that may influence amplitude and implicit time values of the exam, such as age, breed, cataract existence and stage of cataract development and anesthesia or sedation protocol. The aim of this study was to assess age and stage of cataract development interference and, additionally, standardize electroretinogram values in Yorkshire Terrier dogs using sedation. 84 records and 157 eyes were selected from 2006 to 2013 period. The BMP-200 full field electroretinogram system was used along with corneal active ERG-Jet contact lens electrode. Amplitude and implicit time values of rods, mixed rod-cone and cones were obtained. All animals were separated according the following age group: 1 to 5 years old, 6 to 10 years old and 11 to 15 years old. Additionally, the selected eyes were separated by cataract development stage, such as: incipient, immature, mature and hypermature cataract. Two-way ANOVA tests were performed to determine possible difference between cataract stage groups and age groups. Standardize values of each group was reported. There was difference in amplitude values response of rod, mixed rod-cones and cones amplitude in all age groups, in addition to difference in implicit time values of mixed rod-cones in all age groups. Animal age progression was found as the most influent factor in rod, mixed rod-cones and cones amplitude values. Implicit time values, however, exhibit a more stable response values. Cataract stage development was not substantial in influence amplitude values of rod, mixed rodcones and cone final electroretinogram responses. This study has shown that age is the main factor of full field electroretinogram interference in amplitude values response of rod, mixed rod-cones and cones in dogs. The presence of cataract and the development stage were not relevant

Les hallucinations visuelles (HV) sont un symptôme psychotique commun retrouvé de manière transdiagnostique dans les troubles de la vision, les troubles neurologiques et les troubles psychiatriques. Les différents modèles cognitifs des HV s’accordent sur la présence d’une perturbation du traitement de l’information visuelle bottom-up et des processus tardifs top-down pour expliquer la survenue des HV. Dans un première partie de notre travail, nous avons étudié les caractéristiques communes entre les pathologies caractérisées par la présence d’HV et avons constaté que toutes présentent des anomalies structurales ou fonctionnelles de la rétine mais que peu d’études ont exploré le lien entre anomalies fonctionnelles de la rétine et HV. Nous avons ensuite étudié le fonctionnement de la rétine chez des patients souffrant de schizophrénie présentant ou non des HV. Nos résultats ont montré la présence d’anomalies fonctionnelles touchant le système des photorécepteurs et les cellules ganglionnaires de la rétine chez les patients souffrant de schizophrénie et des anomalies fonctionnelles du système des bâtonnets spécifiquement chez les patients présentant des HV. Les anomalies du traitement sensoriel sont une condition nécessaire mais insuffisante pour expliquer la survenue des HV. Ainsi nous avons exploré l’influence du traitement des émotions dans les HV, par une tâche d’amorçage émotionnel sur le traitement de stimuli ambigus chez des sujets sains prônes aux hallucinations et des patients souffrant de schizophrénie. Les premiers résultats intermédiaires présentés montrent en partie que la manipulation d'une amorce émotionnelle pourrait influencer la perception de stimuli ambigus chez les sujets sains prônes aux hallucinations. Ces arguments sont à confirmer par un nouveau protocole de recherche à adapter. Nos résultats nous permettent de discuter l’adaptation d’un modèle des HV dans la schizophrénie. / Visual hallucinations (VH) are a common psychotic symptom present in eye disease, neurological disorders and psychiatric disorders. Cognitive models of VH postulate the disruption of both bottom-up visual information processing and late top-down processes to explain the emergence of VH. In the first part of our work, we have reviewed the common characteristics between pathologies characterized by VH. We have found that structural or functional abnormalities of the retina were systematically present, but few studies have explored the link between these abnormalities and VH. Hence, we have explored the retinal functions in schizophrenia patients with or without VH. We have found photoreceptors and retinal ganglion cells abnormalities in patients with schizophrenia and abnormalities of the rod system specifically in patients with VH. Abnormalities of sensory processing are a necessary but insufficient condition to explain the occurrence of VH. Thus, we have explored the influence of emotion processing in healthy hallucinations prone subjects and schizophrenia patients in an emotional priming task requiring the treatment of ambiguous stimuli. We expose intermediate results which show that the manipulation of an emotional primer can influence the perception of ambiguous stimuli in healthy hallucinations prone subjects. These results need replications in a new research protocol. Our results allow us to discuss the adaptation of a model of VH in schizophrenia.

A retinopatia da prematuridade é uma doença ocular do desenvolvimento associada a um crescimento vascular retiniano anormal e ocorre somente em recém-nascidos com menos de 32 semanas de gestação e submetidos a longos períodos em incubadoras, tipicamente ricas em oxigênio. A doença possui duas fases: (1) a inibição do desenvolvimento normal de vasos na retina, decorrente da hiperóxia induzida pelo ambiente da incubadora; (2) neovascularização retiniana devido ao aumento de fatores de crescimento desencadeados pela pouca disponibilidade de oxigênio fora da incubadora. O objetivo deste trabalho é avaliar a função visual em um modelo animal de retinopatia da prematuridade, comparando-o a animais sadios. Eletrorretinogramas (ERGs) de campo total foram realizados em camundongos (Mus musculus) controle e camundongos submetidos hiperoxigenação em câmara hiperbárica (75% de oxigênio) durante o desenvolvimento retiniano pós-natal para entender as perdas visuais que ocorrem na retinopatia da prematuridade. Foram utilizados 122 animais, divididos em dois grupos: no grupo controle¸ ERGs foram realizados em P17 (n = 32), P30 (n = 26) e P60 (n = 44) com estimulação em comprimentos de onda distintos (LEDs com pico de emissão em 365 nm, 459 nm, 525 nm e 635 nm) para avaliação da atividade funcional da retina ao longo do desenvolvimento, não passando por nenhuma manipulação experimental adicional; no grupo experimental, os animais foram submetidos à hiperoxigenação de P7 a P12 para indução da angiogênese e avaliados com ERGs com estimulação em 459 nm em P17 (n = 7), P30 (n = 6) e P60 (n = 7), para acompanhar o desenvolvimento retiniano. Todos os animais foram adaptados ao escuro por pelo menos duas horas antes da realização dos experimentos. Em sessão de 40 a 60 minutos de duração, os animais foram submetidos a flashes de luz em intensidades crescentes. Amplitudes e latências das ondas a, b e potenciais oscilatórios foram medidas, e relações intensidade-resposta ajustadas com modelos matemáticos diferentes para comparação entre indivíduos e entre grupos. Os parâmetros obtidos com os ajustes foram comparados através de ANOVA e testes T de Student com as devidas correções de Bonferroni. Nos níveis luminosos testados, a onda b do ERG murino é majoritariamente dominada pela atividade dos bastonetes e a onda a majoritariamente dominada pelos cones. Os registros em animais em P17 e P30 do grupo controle foram similares aos realizados em P60 quanto à latência e amplitude de resposta, bem como quanto à sensibilidade e grau de cooperação entre os distintos elementos do ERG. Entretanto, as amplitudes máximas de resposta foram ligeiramente maiores em P30 para todos os comprimentos de onda e houve ligeira redução da sensibilidade absoluta ao longo do desenvolvimento. Para o grupo experimental, os animais em P17 sofreram as maiores perdas, com diminuições nas amplitudes de todos os componentes do ERG, sem prejuízo das latências ou sensibilidade. Também houve uma sucessiva recuperação das respostas ao longo do desenvolvimento animal. Esses achados indicam que o modelo de ROP em camundongos reproduz aspectos essenciais ao quadro patológico severo humano / The retinopathy of prematurity is an ocular developmental disorder associated with abnormal retinal vascular growth and occurs only in neonates younger than 32 weeks of gestation and undergoing long periods in incubators, typically rich in oxygen. The disease has two phases: (1) the inhibition of the normal development of vessels in the retina, due to the hyperoxia induced by the incubator environment; (2) retinal neovascularization due to the increase in growth factors triggered by the low availability of oxygen outside the incubator. The objective of this study is to evaluate the visual function in an animal model of retinopathy of prematurity, comparing it to healthy animals. Full-field electroretinogram (ERGs) were performed on control mice (Mus musculus) and that were exposed to a hyperbaric chamber (75% oxygen) during post-natal retinal development to understand the visual losses that occur in retinopathy of prematurity. We used 122 animals, divided into two groups: in the control group, ERGs were performed at P17 (n = 32), P30 (n = 26) and P60 (n = 44) with stimulation at different wavelengths (LEDs with peak of emission at 365 nm, 459 nm, 525 nm and 635 nm) for evaluation of the functional activity of the retina throughout the development, without any additional experimental manipulation; in the experimental group, animals were submitted to hyperoxogenation of P7 to P12 for induction of angiogenesis and evaluated with ERGs with stimulation at 459 nm in P17 (n = 7), P30 (n = 6) and P60 (n = 7) to follow up retinal development. All animals were dark adapted for at least two hours prior to the experiments. In sessions with 40 to 60 minutes, the animals were subjected to flashes of light at increasing intensities. Amplitudes and latencies of a-waves, b-waves and oscillatory potentials were measured, and intensity-response relationships adjusted with different mathematical models for comparison between individuals and between groups. The parameters obtained with the adjustments were compared through ANOVA and Student\'s T tests with the appropriate Bonferroni correction. In the light levels tested, the murine ERG b-wave is dominated by rod activity and the a-wave is dominated by the cones. The records in animals at P17 and P30 of the control group were similar to those performed at P60 regarding the latency and amplitude of response, as well as the sensitivity and degree of cooperation between the different ERG elements. However, the maximum response amplitudes were slightly higher at P30 at all wavelengths and there was slight reduction of absolute sensitivity throughout development. For the experimental group, the animals at P17 suffered the greatest losses, with decreases in the amplitudes of all the components of the ERG, without prejudice to the latencies or sensitivity. There was also a successive recovery of responses throughout animal development. These findings indicate that the ROP model in mice reproduces aspects essential to the severe human pathology