RESUMEN
Polybia paulista is a neotropical social wasp related to severe accidents and allergic reactions cases, including anaphylaxis, in southeastern Brazil. Antigen 5 (Poly p 5) is a major allergenic protein from its venom with potential use for component-resolved diagnostic. Therefore, the previous characterization of the immune response profile triggered by Poly p 5 should be evaluated. Recombinant Poly p 5 (rPoly p 5) was used to sensitize BALB/c mice with six weekly intradermal doses, and the specific antibody production and the functional profile of CD4+ T cells were assessed. rPoly p 5 induced the production of specific immunoglobulins (sIg) sIgE, sIgG1 and sIgG2a, which could recognize natural Poly p 5 presented in the venom of four different wasp species. rPoly p 5 stimulated in vitro the CD4+ T cells from immunized mice, which showed a significant proliferative response. These antigen-specific CD4+T cells produced IFN-γ and IL-17A cytokines and increased ROR-γT transcription factor expression. No differences between the control group and sensitized mice were found in IL-4 production and GATA-3 and T-bet expression. Interestingly, increased CD25+FoxP3+ regulatory T cells (Tregs) frequency was observed in the splenocyte cell cultures from rPoly p 5 immunized mice after the in vitro stimulation with both P. paulista venom extract and rPoly p 5. Here we showed that rPoly p 5 induces antigen-specific antibodies capable of recognizing Antigen 5 in the venom of four wasp species and modulates antigen-specific CD4+ T cells to IFN-γ production response associated with a Th17 profile in sensitized mice. These findings emphasize the potential use of rPoly p 5 as an essential source of a major wasp allergen with significant immunological properties.
Asunto(s)
Anafilaxia , Avispas , Animales , Ratones , Avispas/metabolismo , Venenos de Avispas/metabolismo , Formación de Anticuerpos , Alérgenos , Linfocitos T CD4-PositivosRESUMEN
OBJECTIVES: White spot lesions (WSL) are prevalent in patients using orthodontic appliances. The presence of ion-releasing compounds in the tooth-appliance interface may limit enamel demineralization to control WSL incidence. Thus, this study aims to evaluate the mineral formation on SiNb-containing experimental orthodontic resins and the influence of these fillers on the physicochemical and biological properties of developed materials. MATERIALS AND METHODS: The SiNb particles were synthesized via the sol-gel route and characterized by their molecular structure and morphology. Photopolymerizable orthodontic resins were produced with a 75 wt% Bis-GMA/25 wt% TEGDMA and 10 wt%, 20 wt%, or 30 wt% addition of SiNb. A control group was formulated without SiNb. These resins were tested for their degree of conversion, softening in solvent, cytotoxicity in fibroblasts, flexural strength, shear bond strength (SBS), and mineral deposition. RESULTS: The addition of 10 wt% of SiNb did not impair the conversion of monomers, cytotoxicity, and flexural strength. All groups with SiNb addition presented similar softening in solvent. The presence of these particles did not affect the bond strength between metallic brackets and enamel, with SBS values ranging from 16.41 to 18.66 MPa. The mineral deposition was observed for all groups. CONCLUSION: The use of niobium silicate as filler particles in resins may be a strategy for the adhesion of orthodontic appliances. The 10 wt% SiNb concentration resulted in a material with suitable physicochemical and biological properties while maintaining the bond strength to tooth enamel and promoting mineral deposition.
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Recubrimiento Dental Adhesivo , Soportes Ortodóncicos , Humanos , Niobio/química , Silicatos , Bisfenol A Glicidil Metacrilato/química , Aparatos Ortodóncicos , Solventes , Ensayo de Materiales , Resistencia al Corte , Cementos de Resina/químicaRESUMEN
Sleep medicine classes and teachings are usually deficient and insufficient during undergraduate medical education. In order to circumvent the educational deficits in sleep medicine, students at a Brazilian Medical School created a sleep medicine interest group-an academic organization for teaching purposes whose administration is carried out by the undergraduate students themselves. This study aims to describe the establishment of a sleep medicine interest group, as well as to evaluate the results of its first edition on the knowledge about sleep medicine among undergraduate medical students. Classes were taken biweekly and consisted of lectures by invited professors, presentation of clinical cases, and discussion with the students. By the end of the course, both attendees and non-attendees were invited to fill out a questionnaire including an objective assessment of knowledge (15 multiple choice questions). The questionnaire was filled out by 32 participants, of which 18 were attendees and 14 were non-attendees. The average result on the final exam was significantly higher among the attendees (6.1 ± 1.2) in comparison with non-attendees (4.9 ± 1.3-p = 0.015). The results demonstrate that an interest group proved to be feasible as a source of complementary information to undergraduate medical students and a valid alternative to circumvent the educational deficits.
RESUMEN
The social wasp Polybia paulista (Hymenoptera, Vespidae) is highly aggressive, being responsible for many medical occurrences. One of the most allergenic components of this venom is Antigen 5 (Poly p 5). The possible modulation of the in vitro immune response induced by antigen 5 from P. paulista venom, expressed recombinantly (rPoly p 5), on BALB/c mice peritoneal macrophages, activated or not with LPS, was assessed. Here, we analyzed cell viability changes, expression of the phosphorylated form of p65 NF-κB subunit, nitric oxide (NO), proinflammatory cytokines production, and co-stimulatory molecules (CD80, CD86). The results suggest that rPoly p 5 does not affect NO production nor the expression of co-stimulatory molecules in mouse peritoneal macrophages. On the other hand, rPoly p 5 induced an increase in IL-1ß production in non-activated macrophages and a reduction in the production of TNF-α and MCP-1 cytokines in activated macrophages. rPoly p 5 decreased the in vitro production of the phosphorylated p65 NF-κB subunit in non-activated macrophages. These findings suggest an essential role of this allergen in the polarization of functional M2 macrophage phenotypes, when analyzed in previously activated macrophages. Further investigations, mainly in in vivo studies, should be conducted to elucidate Polybia paulista Ag5 biological role in the macrophage functional profile modulation.
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Antígenos/toxicidad , Macrófagos Peritoneales/efectos de los fármacos , Venenos de Avispas/química , Avispas/fisiología , Animales , Regulación de la Expresión Génica/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , Óxido Nítrico , Fosforilación , Factor de Transcripción ReIA/genética , Factor de Transcripción ReIA/metabolismo , Venenos de Avispas/toxicidadRESUMEN
Objetivo: Conhecer como ocorre o acesso à saúde das pessoas privadas de liberdade. Métodos: Pesquisa qualitativa, realizada em um presídio no interior de Minas Gerais, com 19 pessoas privadas de liberdade. Os dados foram coletados mediante entrevista aberta orientada por roteiro semiestruturado no período de agosto a dezembro de 2017. Realizou-se Análise de Conteúdo de Bardin. Projeto aprovado no Comitê de Ética e Pesquisa com Seres Humanos. Resultados: Apesar do direito à saúde ser uma prerrogativa constitucional a ser garantida a todo cidadão, inclusive aos privados de liberdade, existem barreiras no cárcere que impedem esse acesso, como: dependência do agente penitenciário por meio de comunicação mediante bilhete, ausência de profissionais de saúde em tempo integral e falta de medicações, necessitando que a família atue como rede de cuidado. Conclusão: Evidencia-se a necessidade de melhor estruturar o acesso à saúde das pessoas privadas de liberdade, a fim de assegurar esse direito.(AU)
Objective: To establish how it occurs the access to health care for people deprived of liberty. Methods: Qualitative research, carried out in a prison Minas Gerais's inland, with 19 people deprived of liberty. Data were collected through open interviews guided by semi-structured rotation from August to December 2017. Bardin's Content Analysis was performed. Project approved by the Ethics and Research with Human Beings Committee. Results: Despite being a constitutional prerogative to be guaranteed to all citizens, including people deprived of liberty, there are prision obstacles that prevent this access, such as: dependence on the prison guard through communication by ticket, absence of a health professional full-time and lack of medication, making it necessary for the family to see itself as a care network. Conclusion: The need to structure the access to health care for people deprived of their liberty, in order to ensure their rights.(AU)
Objetivo: Conocer cómo se dá el acceso a la salud de las personas privó de su libertad. Métodos: Investigación cualitativa, realizada en una prisión del interior de Minas Gerais, con 19 personas privadas de libertad. Los datos fueron coleccionados atraves de una entrevista abierta orientado por un itinerario semi-estructurado. Se realizó el Análisis de Contenido de Bardin. Proyecto aprobado por el Comité de Ética e Investigación con Seres Humanos. Resultados: A pesar de que el derecho a la salud es una prerrogativa constitucional que debe garantizarse a todos los ciudadanos, incluidos los privados de libertad, existen barreras en la prisión que impiden este acceso, tales como: dependencia del guardia penitenciario mediante comunicación vía boleta, ausencia de salud profesionales de salud a tiempo completo y falta de medicación, lo que obliga a la familia a actuar como red asistencial. Conclusión: Se evidencia la necesidad de estructurar mejor el acceso a la salud de las personas privó de su libertad, a fin de garantizar este derecho.(AU)
Asunto(s)
Humanos , Adulto , Persona de Mediana Edad , Prisioneros , Derecho a la Salud , Accesibilidad a los Servicios de Salud , Prisiones/provisión & distribución , Atención a la Salud , Investigación CualitativaRESUMEN
Herbicides are hazardous organic pollutants that contribute to the risk of environmental contamination. The aim of this work was to investigate the synergistic effect of silver (Ag) and gold (Au) bimetallic nanoparticles deposited on palygorskite (PAL) in the presence of TiO2 for photodegradation of bentazone (BTZ) herbicide under UV light. Ag and Au@Ag nanoparticles exhibited an average size below 75 nm and surface charge values less than - 30 mV. UV-Vis spectroscopy indicates the formation of core@shell bimetallic nanoparticles. XRD results showed the interactions between the NPs and the palygorskite structure. SEM images clearly illustrate the presence of small spherical particles distributed in the clay fibers. The control of the size and distribution of the nanoparticles played an important role in the properties of the composites. The degradation of the herbicide BTZ showed that nanoparticles, clay, and only TiO2 did not produce satisfactory results; however, when Ag-Pal and Au@Ag-Pal were in the presence of the TiO2, the degradation was efficient. The best photodegradative system was Au@Ag-Pal+TiO2, which was maintained after the third cycle. The bentazone photodegradation using Au@Ag-PAL+TiO2 exhibited toxicity against Artemia salina. Therefore, Au@Ag-PAL+TiO2 photocatalyst showed that the synergy of bimetallic nanoparticles deposited on clay for enhanced photodegradation activity of bentazone herbicide.
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Nanopartículas del Metal , Plata , Oro , Compuestos de Magnesio , Fotólisis , Compuestos de Silicona , TitanioRESUMEN
Dimorphandra gardneriana Tulasne é conhecida como fava danta, é uma árvore brasileira, naturalmente do Cerrado e Caatinga, têm uma importância ecológica e funcional, seus frutos são ricos em flavonoides (rutina, quercetina, isoquercitrina). O objetivo deste trabalho foi estudar a estabilidade térmica da fava danta e da rutina purifica através da termogravimetria. As amostras foram analisadas no Termogravimétrico Shimadzu, TGA-51, no Laboratório de Materiais do IFPI, onde foram acondicionadas em porta-amostras de platina, com atmosfera de nitrogênio e com fluxo de 50 mL/min. A temperatura foi elevada a 600°C, com taxa de aquecimento de 2 °C/min. Obteve-se sucesso com a purificação da fava danta, pois a rutina obtida teve maior uniformidade nos eventos térmicos e maior estabilidade térmica em relação a fava.
Asunto(s)
Fabaceae/química , Respuesta al Choque Térmico/fisiología , Rutina/aislamiento & purificación , Termotolerancia/fisiología , Calor/efectos adversos , TermogravimetríaRESUMEN
Dimorphandra gardneriana Tulasne é conhecida como fava danta, é uma árvore brasileira, naturalmente do Cerrado e Caatinga, têm uma importância ecológica e funcional, seus frutos são ricos em flavonoides (rutina, quercetina, isoquercitrina). O objetivo deste trabalho foi estudar a estabilidade térmica da fava danta e da rutina purifica através da termogravimetria. As amostras foram analisadas no Termogravimétrico Shimadzu, TGA-51, no Laboratório de Materiais do IFPI, onde foram acondicionadas em porta-amostras de platina, com atmosfera de nitrogênio e com fluxo de 50 mL/min. A temperatura foi elevada a 600°C, com taxa de aquecimento de 2 °C/min. Obteve-se sucesso com a purificação da fava danta, pois a rutina obtida teve maior uniformidade nos eventos térmicos e maior estabilidade térmica em relação a fava.(AU)
Asunto(s)
Rutina/aislamiento & purificación , Fabaceae/química , Termotolerancia/fisiología , Respuesta al Choque Térmico/fisiología , Termogravimetría , Calor/efectos adversosRESUMEN
A paraparesia espástica é caracterizada pela perda de função total ou parcial dos membros inferiores associado ao aumento do tônus muscular velocidade-dependente. A toxina botulínica é utilizada no tratamento de diversos padrões de espasticidade, sejam em flexão, extensão ou adução. Objetivo: determinar a eficácia e segurança do bloqueio químico com toxina botulínica em pacientes com paraparesia espástica. Método: foi realizada uma revisão sistemática com busca nas bases de dados do PUBMED, MEDLINE, LILACS e SCIELO. Os critérios de inclusão foram: ensaios clínicos que utilizaram a toxina botulínica para o tratamento de pacientes com paraparesia espástica e publicados em inglês a partir da década de 1980. Os desfechos considerados foram: a pontuação na Escala de Ashworth Modificada, a amplitude de movimento passiva e ativa e os efeitos adversos da toxina botulínica. Resultados: foram incluídos cinco artigos. Todos mostraram melhora da espasticidade nos pacientes estudados. Quatro artigos mostraram aumento da amplitude de movimento passivo e três relataram aumento da amplitude de movimento ativo. Três artigos trouxeram relatos de efeitos adversos após o uso da toxina botulínica, mas a maioria deles não eram graves e cessaram espontaneamente. Conclusão: os estudos analisados mostraram que a toxina botulínica é eficaz e segura em pacientes com paraparesia espástica.(AU)
Spastic paraparesis is the loss of total or partial lower limb function associated with increased speed-dependent muscle tone. Botulinum toxin is used in the treatment of several spasticity presentations that include flexion, extension and adduction. Objective: To determine both safety and efficacy of botulinum toxin as a blocking agent in the treatment of spastic paraparesis. Method:A systematic review was carried out with a search on PUBMED, MEDLINE, LILACS and SCIELO databases. The inclusion criteria were: clinical trials that used botulinum toxin for the treatment of patients with spastic paraparesis and published in English from the 1980s. The following outcomes were assessed by the studies: the Ashworth Modified scale score, the range of passive and active motion and botulinum toxin adverse effects. Results:Five articles were included. All of them showed spasticity improvements in the patients. Four studies showed increases in passive range of motion and three articles showed increase in active range of motion. Three papers reported adverse effects after botulinum toxin use but they were mostly mild and ceased spontaneously. Conclusion: Most analyzed studies indicated that botulinum toxin is safe and efficient inthe treatment of spastic paraparesis. (AU)
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Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Toxinas Botulínicas Tipo A/uso terapéutico , Paraparesia Espástica/diagnóstico , Paraparesia Espástica/tratamiento farmacológico , Esclerosis Múltiple/diagnóstico , Esclerosis Múltiple/tratamiento farmacológico , Literatura de Revisión como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del TratamientoRESUMEN
El trabajo pretende ver cómo el ascenso del modelo económico neoliberal reconfigura las relaciones políticas y organizativas en el agro argentino. En ese sentido, intentaremos analizar el contexto socio-político en que nace el MNCI (Movimiento Nacional Campesino Indígena), las relaciones posibles entre el ascenso neoliberal y el nacimiento del Movimiento; sus formas organizativas y los cuestionamientos que el MNCI hace al modelo económico imperante, y la lógica productiva propugnada por éste (agronegocio, monocultivos, transgénico, etc.). Siendo así, pretendemos hacer un análisis del aumento productivo impulsado con el neoliberalismo y los cambios en los "modos" de producción en el "campo" realizados en las últimas décadas, paralelo al surgimiento del MNCI contestando este modelo desde una mirada "contrahegemónica". Por consiguiente, analizaremos las distintas formas de intervención y construcción de territorios trazadas, por un lado, de forma hegemónica desde el ascenso neoliberal y el advenimiento de los productos transgénicos y, por el otro, frente a las proposiciones planteadas por el MNCI y su propuesta agroecológica y "campesina". En este sentido, la "cuestión ambiental" toma centralidad en los análisis de los cambios productivos y de política económica realizados con el avance neoliberal y sus efectos sociales en el "agro" (éxodo rural, desposesión, etc.), que incrementan el avance del "modelo neocolonial extractivo" y generan impactos significativos hacia los ecosistemas naturales y sus ciclos reproductivos. Las distintas formas/propuestas de apropiación de estos ecosistemas, y los distintos impactos producidos por cada una, van a ser problematizados en el presente trabajo.
This article intends to see show how of the neoliberal economic model ascent reconfigures the political and organizational relations in the Argentinean agrarian world. According to this, we will try to analyze the social-political context where the MNCI (National Peasant Indian Movement) was born, the possible links between the neoliberal ascent and the birth of the Movement; their organizational structures and what questions the MNCI asks to the prevalent economic model, and the productive logic it defends (agribusiness, monocultures, transgenic cultivation, etc.) We intend carry out an analysis of the productive increase boosted by neoliberalism and the changes in the "ways" of production in the "country" carried out in the last decades, in parallel to the birth of the MNCI questioning this model from an "anti-hegemonic" perspective. As a consequence, we will analyze different ways of intervention and construction of territories drawn on one side in an hegemonic form from the neoliberal ascent and the transgenic products advent, and on the other side facing the propositions exposed by the MNCI and their agricultural-ecological and "peasant" proposal. In this sense, the "environmental issue" becomes central in the analysis of the productive changes and the economic policy accomplished with the neoliberal advance and its social effects in the "farming world" (rural exodus, dispossess, etc.) which increases the advance of the extractive "neocolonial model" and produces relevant impact on the natural ecosystems and their reproductive cycles. The different appropriation proposals/forms of these ecosystems, and the different impacts produced by each one, will be developed in this work.
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Humanos , Agricultura , Política , Cambio Ambiental , MovimientoRESUMEN
Introduction: Highly-diluted medicines are used in clinical practice to treat many pathologies of pigs [1-4]. This therapeutic tool had its potential for valued use due to the global scenario changing on the restriction to limit of antimicrobial residues in the security feeding and production of foods from animal origin for human consume, especially the meat production [5].Conclusion: Through the evidence of mass measurement, the usage profile of group B treatment shown to work with pigs and give greater weight live gain in group A during the available trial. Future studies should be conducted with larger numbers of animals to confirm the incidence of the unique profile, with replications to assess the complete production cycle, including the relationship ending / sow / year. Finally, other scales and dilutions should be analyzed to adjust for best answer from the best treatment effect profile.(AU)
Introdução: Medicamentos ultra-diluídos são utilizados na prática clínica no tratamento de diversas patologias de suínos [1-4]. Esta modalidade terapêutica teve seu potencial de utilização valorizado devido à mudança do cenário mundial sobre limite de resíduos de antimicrobianos na segurança alimentar e produção de alimentos de origem animal para consumo humano, especialmente a produção de carne [5].Conclusão: Através das evidências de aferição de massa, o perfil de utilização de tratamento do grupo B demonstrou funcionar com suínos e proporcionar maior ganho de peso vivo em relação ao grupo A durante o período estudado. Futuros trabalhos deverão ser realizados com maior número de animais para confirmação da incidência do perfil único, com repetições que avaliem o ciclo produtivo completo, inclusive a relação terminados/porca/ano. Finalmente, outras escalas e potencias devem ser testados para ajustar a resposta a partir do perfil de tratamento de melhor efeito.(AU)
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Animales , Aumento de Peso , Altas Potencias , Complejos Farmacéuticos Homeopáticos , Industria AgropecuariaRESUMEN
The transformation of spatial (SF) and temporal frequency (TF) tuning functions from broad-band/low-pass to narrow band-pass profiles is one of the key emergent properties of neurons in the mammalian primary visual cortex (V1). The mechanisms underlying such transformation are still a matter of ongoing debate. With the aim of providing comparative insights into the issue, we analyzed various aspects of the spatiotemporal tuning dynamics of neurons in the visual wulst of four awake owls. The wulst is the avian telencephalic target of the retinothalamofugal pathway and, in owls, bears striking functional analogy with V1. Most neurons in our sample exhibited fast and large-magnitude adaptation to the visual stimuli with response latencies very similar to those reported for V1. Moreover, latency increased as a function of stimulus SF but not TF, which suggests that parvo- and magno-like geniculate inputs could be converging onto single wulst neurons. No net shifts in preferred SF or TF were observed along the initial second of stimulation, but bandwidth decreased roughly during the first 200 ms after response latency for both stimulus dimensions. For SF, this occurred exclusively as a consequence of low-frequency suppression, whereas suppression was observed both at the low- and high-frequency limbs of TF tuning curves. Overall these results indicate that SF and TF tuning curves in the wulst are shaped by both feedforward and intratelencephalic suppressive mechanisms, similarly to what seems to be the case in the mammalian striate cortex.
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Potenciales de Acción/fisiología , Percepción de Movimiento/fisiología , Neuronas/fisiología , Dinámicas no Lineales , Orientación/fisiología , Corteza Visual/citología , Animales , Modelos Neurológicos , Estimulación Luminosa/métodos , Tiempo de Reacción/fisiología , Estrigiformes/fisiología , Factores de Tiempo , Vías Visuales/fisiología , VigiliaRESUMEN
The avian visual wulst is hodologically equivalent to the mammalian primary visual cortex (V1). In contrast to most birds, owls have a massive visual wulst, which shares striking functional similarities with V1. To provide a better understanding of how motion is processed within this area, we used sinusoidal gratings to characterize the spatiotemporal frequency and speed tuning profiles of 131 neurones recorded from awake burrowing owls. Cells were found to be clearly tuned to both spatial and temporal frequencies, and in a way that is similar to what has been reported in the striate cortex of primates and carnivores. Our results also suggest the presence of spatial frequency tuning domains in the wulst. Speed tuning was assessed by several methods devised to measure the degree of dependence between spatial and temporal frequency tuning. Although many neurones were found to be independently tuned, a significant proportion of cells showed at least some degree of dependence, compatible with the idea that some kind of initial transformation towards an explicit representation of speed is being carried out by the owl wulst. Interestingly, under certain constraints, a higher incidence of spatial frequency-invariant speed tuned profiles was obtained by combining our experimentally measured responses using a recent cortical model of speed tuning. Overall, our findings reinforce the notion that, like V1, the owl wulst is an important initial stage for motion processing, a function that is usually attributed to areas of the tectofugal pathway in lateral-eyed birds.
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Percepción de Movimiento/fisiología , Neuronas/fisiología , Telencéfalo/fisiología , Potenciales de Acción , Algoritmos , Animales , Modelos Lineales , Microelectrodos , Distribución Normal , Estimulación Luminosa , Estrigiformes , Factores de Tiempo , Vías Visuales/fisiología , Percepción Visual/fisiologíaRESUMEN
The avian retinothalamofugal pathway reaches the telencephalon in an area known as visual wulst. A close functional analogy between this area and the early visual cortex of mammals has been established in owls. The goal of the present study was to assess quantitatively the directional selectivity and motion integration capability of visual wulst neurones, aspects that have not been previously investigated. We recorded extracellularly from a total of 101 cells in awake burrowing owls. From this sample, 88% of the units exhibited modulated directional responses to sinusoidal gratings, with a mean direction index of 0.74 +/- 0.03 and tuning bandwidth of 28 +/- 1.16 degrees . A direction index higher than 0.5 was observed in 66% of the cells, thereby qualifying them as direction selective. Motion integration was tested with moving plaids, made by adding two sinusoidal gratings of different orientations. We found that 80% of direction-selective cells responded optimally to the motion direction of the component gratings, whereas none responded to the global motion of plaids, whose direction was intermediate to that of the gratings. The remaining 20% were unclassifiable. The strength of component motion selectivity rapidly increased over a 200 ms period following stimulus onset, maintaining a relatively sustained profile thereafter. Overall, our data suggest that, as in the mammalian primary visual cortex, the visual wulst neurones of owls signal the local orientated features of a moving object. How and where these potentially ambiguous signals are integrated in the owl brain might be important for understanding the mechanisms underlying global motion perception.
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Percepción de Movimiento/fisiología , Neuronas/fisiología , Orientación/fisiología , Estrigiformes/fisiología , Telencéfalo/citología , Vigilia , Potenciales de Acción/fisiología , Análisis de Varianza , Animales , Estimulación Luminosa/métodos , Vías Visuales/fisiologíaRESUMEN
We investigated age-related changes in learning and memory performance and behavioural extinction in the water maze; and in endogenous levels of serotonin (5-HT) and 5-hydroxyindole acetic acid (5-HIAA) in the neocortex, hippocampus, thalamus and dorsal raphe nucleus of Wistar rats. Another aim was to assess the correlation between behavioural and biochemical parameters, which were measured in rodents of two different ages: 5 months (adults) and 16 months (middle-aged). The middle-aged subjects succeeded in learning the behavioural task, albeit with significantly worse performance when compared to adult animals. Aging also had significant main effects on memory and extinction. An age-dependent decrease in 5-HIAA levels was observed in both hippocampus and dorsal raphe nucleus (DRN). The decrease in DRN 5-HIAA was paralleled by a decrease in 5-HIAA/5-HT ratio in this brain area, which was significantly correlated to the animals' spatial memory performance and behavioural extinction. In addition, using middle-aged rats, a 2x2 factorial study was carried out to examine the effects of food restriction and chronic ethanol consumption on rat's performance in a spatial behavioural task and on central serotonergic parameters. None of these two treatments had a significant effect on the behavioural and biochemical parameters assessed, with the exception of extinction index, which was significantly affected by ethanol consumption. Long-term ethanol ameliorated the impairment in behavioural flexibility caused by aging. In conclusion, long-term ethanol consumption may have a role in protecting against age-related deficit in behavioural extinction. Moreover, the present results also indicate that DRN serotonergic system is involved in spatial memory and behavioural extinction.
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Envejecimiento/fisiología , Consumo de Bebidas Alcohólicas/fisiopatología , Extinción Psicológica/fisiología , Ácido Hidroxiindolacético/metabolismo , Núcleos del Rafe/metabolismo , Serotonina/metabolismo , Análisis de Varianza , Animales , Conducta Animal , Peso Corporal/efectos de los fármacos , Peso Corporal/fisiología , Química Encefálica/efectos de los fármacos , Depresores del Sistema Nervioso Central/administración & dosificación , Ingestión de Alimentos/efectos de los fármacos , Ingestión de Alimentos/fisiología , Etanol/administración & dosificación , Extinción Psicológica/efectos de los fármacos , Masculino , Aprendizaje por Laberinto/fisiología , Núcleos del Rafe/efectos de los fármacos , Ratas , Ratas WistarRESUMEN
Chronic ethanol intake causes various types of neural damage and behavioral impairments, probably acting through oxidative stress and excitotoxicity, while dietary restriction is considered by some authors to protect the central nervous system from these kinds of damage. In the present study, a factorial experimental design was used to investigate the effects of chronic ethanol and dietary restriction treatments, associated or not, on Wistar rats' exploratory behavior, spatial memory aspects and cortical and hippocampal acetylcholinesterase (AChE) activity. Dietary restriction lasted for the whole experiment, while ethanol treatment lasted for only 3 weeks. Despite the short ethanol treatment duration, for two behavior categories assessed, moving and rearing, an interaction was observed between the effects of chronic ethanol and dietary restriction. There were no significant differences in AChE activities among the groups. Cerebellar neural nitric oxide synthase (nNOs) activity was measured as a first step to assess oxidative stress. Dietary restriction significantly reduced NO formation. The present results indicate that dietary restriction might exert a protective effect against chronic-ethanol-induced changes in exploratory behavior. It is hypothesized that the mechanisms underlying this protection can involve prevention of oxidative stress.