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1.
Animals (Basel) ; 13(23)2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-38066961

RESUMO

The modern lifestyle of humans is leading to a limited exposure to nature. While several wild species are adapting and thriving in anthropic environments, natural history knowledge is declining, and positive attitudes and behaviours towards nature are facing challenges. Because anticipating attitudes and engendering broad-based support for nature-related measures requires a good grasp of social contexts, we set out to evaluate the sociodemographic factors driving the perception, attitudes towards, and natural history knowledge of a keystone species-the European hedgehog. In 2022, we conducted a questionnaire answered by 324 Portuguese adults. We found generally positive feelings and attitudes towards this species. A higher degree of academic qualifications and previous personal experience with the species seem to play a role in (i) people's perception about human impacts on hedgehogs and (ii) positive attitudes, especially during encounters where the animals were in difficulty. Despite this, the extent of natural history knowledge was low overall, and the study population was self-aware of this. Our insights underline the need to tailor educational programmes if we are to encourage people to re-establish meaningful connections with nature, to foster social support for biodiversity stewardship, and to implement the One Health approach in a way that resonates with distinct social groups.

3.
Acta Neuropsychiatr ; 33(2): 55-64, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33256871

RESUMO

OBJECTIVE: The present study was designed to test the hypothesis that there is a reduction in the activity of the enzyme cytochrome c oxidase (Cox) in Alzheimer's disease (AD). METHODS: Systematic review of literature and meta-analysis were used with data obtained from the PubMed, Scopus, MEDLINE, Lilacs, Eric and Cochrane. The keywords were Alzheimer's AND Cox AND mitochondria; Alzheimer's AND Cox AND mitochondria; Alzheimer's AND complex IV AND mitochondria. A total of 1372 articles were found, 23 of them fitting the inclusion criteria. The data were assembled in an Excel spreadsheet and analysed using the RevMan software. A random effects model was adopted to the estimative of the effect. RESULTS: The data shows a significant decrease in the activity of the Cox AD patients and animal models. CONCLUSION: Cox enzyme may be an important molecular component involved in the mechanisms underlying AD. Therefore, this enzyme may represent a possible new biomarker for the disease as a complementary diagnosis and a new treatment target for AD.


Assuntos
Doença de Alzheimer/enzimologia , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias/enzimologia , Doença de Alzheimer/diagnóstico , Animais , Colorimetria/métodos , Humanos , Camundongos , Mitocôndrias/metabolismo , Modelos Animais , Polarografia/métodos , Ratos , Software , Espectrofotometria/métodos
4.
Nature ; 587(7833): 252-257, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33177665

RESUMO

Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity1-4. Sparse taxon sampling has previously been proposed to confound phylogenetic inference5, and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic and molecular diversity, by analysing 363 genomes from 92.4% of bird families-including 267 newly sequenced genomes produced for phase II of the Bird 10,000 Genomes (B10K) Project. We use this comparative genome dataset in combination with a pipeline that leverages a reference-free whole-genome alignment to identify orthologous regions in greater numbers than has previously been possible and to recognize genomic novelties in particular bird lineages. The densely sampled alignment provides a single-base-pair map of selection, has more than doubled the fraction of bases that are confidently predicted to be under conservation and reveals extensive patterns of weak selection in predominantly non-coding DNA. Our results demonstrate that increasing the diversity of genomes used in comparative studies can reveal more shared and lineage-specific variation, and improve the investigation of genomic characteristics. We anticipate that this genomic resource will offer new perspectives on evolutionary processes in cross-species comparative analyses and assist in efforts to conserve species.


Assuntos
Aves/classificação , Aves/genética , Genoma/genética , Genômica/métodos , Genômica/normas , Filogenia , Animais , Galinhas/genética , Conservação dos Recursos Naturais , Conjuntos de Dados como Assunto , Tentilhões/genética , Humanos , Seleção Genética/genética , Sintenia/genética
5.
Gigascience ; 9(1)2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31942620

RESUMO

BACKGROUND: The giant squid (Architeuthis dux; Steenstrup, 1857) is an enigmatic giant mollusc with a circumglobal distribution in the deep ocean, except in the high Arctic and Antarctic waters. The elusiveness of the species makes it difficult to study. Thus, having a genome assembled for this deep-sea-dwelling species will allow several pending evolutionary questions to be unlocked. FINDINGS: We present a draft genome assembly that includes 200 Gb of Illumina reads, 4 Gb of Moleculo synthetic long reads, and 108 Gb of Chicago libraries, with a final size matching the estimated genome size of 2.7 Gb, and a scaffold N50 of 4.8 Mb. We also present an alternative assembly including 27 Gb raw reads generated using the Pacific Biosciences platform. In addition, we sequenced the proteome of the same individual and RNA from 3 different tissue types from 3 other species of squid (Onychoteuthis banksii, Dosidicus gigas, and Sthenoteuthis oualaniensis) to assist genome annotation. We annotated 33,406 protein-coding genes supported by evidence, and the genome completeness estimated by BUSCO reached 92%. Repetitive regions cover 49.17% of the genome. CONCLUSIONS: This annotated draft genome of A. dux provides a critical resource to investigate the unique traits of this species, including its gigantism and key adaptations to deep-sea environments.


Assuntos
Decapodiformes/genética , Genoma , Genômica , Animais , Evolução Biológica , Cromatografia Líquida , Biologia Computacional/métodos , Elementos de DNA Transponíveis , Perfilação da Expressão Gênica , Genômica/métodos , Anotação de Sequência Molecular , Família Multigênica , RNA não Traduzido , Espectrometria de Massas em Tandem , Transcriptoma , Sequenciamento Completo do Genoma
6.
Mol Ecol ; 28(16): 3709-3721, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31291502

RESUMO

Arid environments provide ideal ground for investigating the mechanisms of adaptive evolution. High temperatures and low water availability are relentless stressors for many endotherms, including birds; yet birds persist in deserts. While physiological adaptation probably involves metabolic phenotypes, the underlying mechanisms (plasticity, genetics) are largely uncharacterized. To explore this, we took an intraspecific approach that focused on a species that is resident over a mesic to arid gradient, the Karoo scrub-robin (Cercotrichas coryphaeus). Specifically, we integrated environmental (climatic and primary productivity), physiological (metabolic rates: a measure of energy expenditure), genotypic (genetic variation underlying the machinery of energy production) and microbiome (involved in processing food from where energy is retrieved) data, to infer the mechanism of physiological adaptation. We that found the variation in energetic physiology phenotypes and gut microbiome composition are associated with environmental features as well as with variation in genes underlying energy metabolic pathways. Specifically, we identified a small list of candidate adaptive genes, some of them with known ties to relevant physiology phenotypes. Together our results suggest that selective pressures on energetic physiology mediated by genes related to energy homeostasis and possibly microbiota composition may facilitate adaptation to local conditions and provide an explanation to the high avian intraspecific divergence observed in harsh environments.


Assuntos
Adaptação Fisiológica , Clima Desértico , Passeriformes/fisiologia , Animais , Metabolismo Basal , Microbioma Gastrointestinal , Interação Gene-Ambiente , Estudos de Associação Genética , Genética Populacional , Genótipo , Fenótipo , África do Sul
7.
Mar Genomics ; 45: 11-15, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30447893

RESUMO

Bivalve molluscs of the genus Mytilus are considered a model organism in ecotoxicology and are known to be well adapted to marine ecosystems affected by multiple anthropogenic factors, including pollution. In order to assess whether pollution interferes with the reproductive success of Mytilus and affects the diversity within and between populations, we sequenced the transcriptomes of 72 individuals from 9 populations of Mytilus galloprovincialis collected along a ca. 130-km north-south transect on the Western coast of the Iberian Peninsula. We found that polluted areas are acting as a barrier to gene flow, potentially because of the detrimental effect of anthropogenic chemicals on larvae carried from more pristine environments. Furthermore, we observed an increase in genetic diversity in populations from polluted site, which could be indicative of higher mutagenicity driven by the environment. We propose that a microevolutionary perspective is essential for a full characterization of human activities on the dispersal of M. galloprovincialis and that it should be incorporated into management, and conservation plans and policies in the context of the effects of pollution on populations.


Assuntos
Variação Genética/efeitos dos fármacos , Mytilus/genética , Transcriptoma/efeitos dos fármacos , Poluição Química da Água/efeitos adversos , Animais , Metagenômica , Portugal , Espanha
8.
Proc Biol Sci ; 284(1850)2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-28250188

RESUMO

Coleoid cephalopod molluscs comprise squid, cuttlefish and octopuses, and represent nearly the entire diversity of modern cephalopods. Sophisticated adaptations such as the use of colour for camouflage and communication, jet propulsion and the ink sac highlight the unique nature of the group. Despite these striking adaptations, there are clear parallels in ecology between coleoids and bony fishes. The coleoid fossil record is limited, however, hindering confident analysis of the tempo and pattern of their evolution. Here we use a molecular dataset (180 genes, approx. 36 000 amino acids) of 26 cephalopod species to explore the phylogeny and timing of cephalopod evolution. We show that crown cephalopods diverged in the Silurian-Devonian, while crown coleoids had origins in the latest Palaeozoic. While the deep-sea vampire squid and dumbo octopuses have ancient origins extending to the Early Mesozoic Era, 242 ± 38 Ma, incirrate octopuses and the decabrachian coleoids (10-armed squid) diversified in the Jurassic Period. These divergence estimates highlight the modern diversity of coleoid cephalopods emerging in the Mesozoic Marine Revolution, a period that also witnessed the radiation of most ray-finned fish groups in addition to several other marine vertebrates. This suggests that that the origin of modern cephalopod biodiversity was contingent on ecological competition with marine vertebrates.


Assuntos
Evolução Biológica , Cefalópodes/classificação , Filogenia , Animais , Biodiversidade , Fósseis
9.
Mar Genomics ; 31: 1-8, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27650377

RESUMO

Marine ecosystems occupy 71% of the surface of our planet, yet we know little about their diversity. Although the inventory of species is continually increasing, as registered by the Census of Marine Life program, only about 10% of the estimated two million marine species are known. This lag between observed and estimated diversity is in part due to the elusiveness of most aquatic species and the technical difficulties of exploring extreme environments, as for instance the abyssal plains and polar waters. In the last decade, the rapid development of affordable and flexible high-throughput sequencing approaches have been helping to improve our knowledge of marine biodiversity, from the rich microbial biota that forms the base of the tree of life to a wealth of plant and animal species. In this review, we present an overview of the applications of genomics to the study of marine life, from evolutionary biology of non-model organisms to species of commercial relevance for fishing, aquaculture and biomedicine. Instead of providing an exhaustive list of available genomic data, we rather set to present contextualized examples that best represent the current status of the field of marine genomics.


Assuntos
Aquicultura , Organismos Aquáticos/genética , Evolução Biológica , Pesqueiros , Genômica , Oceanos e Mares
10.
BMC Evol Biol ; 15: 124, 2015 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-26123414

RESUMO

BACKGROUND: Hemostasis is a defense mechanism that enhances an organism's survival by minimizing blood loss upon vascular injury. In vertebrates, hemostasis has been evolving with the cardio-vascular and hemodynamic systems over the last 450 million years. Birds and mammals have very similar vascular and hemodynamic systems, thus the mechanism that blocks ruptures in the vasculature is expected to be the same. However, the speed of the process varies across vertebrates, and is particularly slow for birds. Understanding the differences in the hemostasis pathway between birds and mammals, and placing them in perspective to other vertebrates may provide clues to the genetic contribution to variation in blood clotting phenotype in vertebrates. We compiled genomic data corresponding to key elements involved in hemostasis across vertebrates to investigate its genetic basis and understand how it affects fitness. RESULTS: We found that: i) fewer genes are involved in hemostasis in birds compared to mammals; and ii) the largest differences concern platelet membrane receptors and components from the kallikrein-kinin system. We propose that lack of the cytoplasmic domain of the GPIb receptor subunit alpha could be a strong contributor to the prolonged bleeding phenotype in birds. Combined analysis of laboratory assessments of avian hemostasis with the first avian phylogeny based on genomic-scale data revealed that differences in hemostasis within birds are not explained by phylogenetic relationships, but more so by genetic variation underlying components of the hemostatic process, suggestive of natural selection. CONCLUSIONS: This work adds to our understanding of the evolution of hemostasis in vertebrates. The overlap with the inflammation, complement and renin-angiotensin (blood pressure regulation) pathways is a potential driver of rapid molecular evolution in the hemostasis network. Comparisons between avian species and mammals allowed us to hypothesize that the observed mammalian innovations might have contributed to the diversification of mammals that give birth to live young.


Assuntos
Evolução Biológica , Variação Genética , Hemostasia , Vertebrados/classificação , Vertebrados/genética , Animais , Aves/classificação , Aves/genética , Aves/fisiologia , Fatores de Coagulação Sanguínea/genética , Fatores de Coagulação Sanguínea/fisiologia , Evolução Molecular , Filogenia , Seleção Genética
11.
J Avian Med Surg ; 29(4): 282-9, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26771317

RESUMO

Currently available assay methods and reagents are not optimized for evaluating avian hemostasis; therefore, assessing avian coagulopathies is challenging. Recently, thromboelastography (TEG), which measures the viscoelastic properties of blood, has been used clinically in mammalian species to diagnose and characterize hemostatic disorders. To evaluate TEG in healthy individuals of 6 avian species, we modified existing mammalian TEG protocols to allow analysis of citrated, avian whole-blood samples collected from scarlet ibis (Eudocimus ruber) (n = 13), American flamingos ( Phoenicopterus ruber ) (n = 13), helmeted Guinea fowl ( Numida meleagris ) (n = 12), Amazon parrots (Amazona species) (n = 9), Humboldt penguins ( Spheniscus humboldti ) (n = 6), and domestic chickens (n = 16). Activated partial thromboplastin time, prothrombin time, and fibrinogen were measured as a means of comparison. Regardless of the mode of activation, clot formation in the species studied was markedly delayed compared with mammals. Because of prolonged reaction time (14.7-52.7 minutes) with kaolin and diluted tissue factor, undiluted human tissue factor was used in all avian samples because it provided the shortest reaction time. Species differed significantly in reaction time (P = .007), clotting rate (P < .001), rate of clot formation (α angle; P < .001), and maximum amplitude (P < .001) values, indicating that species-specific reference intervals are necessary. Based on these results, TEG with specific reference intervals could prove useful in evaluating avian hemostatic disorders.


Assuntos
Aves/sangue , Tromboelastografia/veterinária , Animais , Aves/classificação , Feminino , Masculino , Valores de Referência , Especificidade da Espécie
12.
PeerJ ; 2: e640, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25374783

RESUMO

An influential hypothesis proposed by Greenwood (1980) suggests that different mating systems result in female and male-biased dispersal, respectively, in birds and mammals. However, other aspects of social structure and behavior can also shape sex-biased dispersal. Although sex-specific patterns of kin cooperation are expected to affect the benefits of philopatry and dispersal patterns, empirical evidence is scarce. Unlike many mammals, Saguinus geoffroyi (Geoffroy's tamarin) has a breeding system in which typically multiple males mate with a single breeding female. Males typically form cooperative reproductive partnerships between relatives, whereas females generally compete for reproductive opportunities. This system of cooperative polyandry is predicted to result in female-biased dispersal, providing an opportunity to test the current hypotheses of sex-biased dispersal. Here we test for evidence of sex-biased dispersal in S. geoffroyi using demographic and genetic data from three populations. We find no sex bias in natal dispersal, contrary to the prediction based on the mating patterns. This pattern was consistent after controlling for the effects of historical population structure. Limited breeding opportunities within social groups likely drive both males and females to disperse, suggesting that dispersal is intimately related to the social context. The integration of genetic and field data revealed that tamarins are another exception to the presumed pattern of male-biased dispersal in mammals. A shift in focus from mating systems to social behavior, which plays a role in most all processes expected to influence sex-bias in dispersal, will be a fruitful target for research both within species and across taxa.

13.
PLoS One ; 9(2): e85903, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24516521

RESUMO

Advances in understanding the process of species formation require an integrated perspective that includes the evaluation of spatial, ecological and genetic components. One approach is to focus on multiple stages of divergence within the same species. Species that comprise phenotypically different populations segregated in apparently distinct habitats, in which range is presently continuous but was putatively geographically isolated provide an interesting system to study the mechanisms of population divergence. Here, we attempt to elucidate the role of ecology and geography in explaining observed morphological and genetic variation in an understorey-dwelling bird endemic to southeastern Africa, where two subspecies are recognized according to phenotype and habitat affinity. We carried out a range-wide analysis of climatic requirements, morphological and genetic variation across southeast Africa to test the hypothesis that the extent of gene flow among populations of the brown scrub-robin are influenced by their distinct climatic niches. We recovered two distinct trends depending on whether our analyses were hierarchically structured at the subspecies or at the within subspecies level. Between subspecies we found pronounced morphological differentiation associated with strong reproductive isolation (no gene flow) between populations occupying divergent climatic niches characterized by changes in the temperature of the warmest and wettest month. In contrast, within subspecies, we recovered continuous morphological variation with extensive gene flow among populations inhabiting the temperate and sub-tropical forests of southern Africa, despite divergence along the climate axis that is mainly determined by minimum temperature and precipitation of the coldest months. Our results highlight the role of niche divergence as a diversifying force that can promote reproductive isolation in vertebrates.


Assuntos
Ecologia , Ecossistema , Variação Genética , Animais , Aves , Fenótipo , África do Sul
14.
Ecol Evol ; 2(11): 2710-21, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23170207

RESUMO

The range of a species is the result of the relative contribution of spatial tracking of environmental requirements and adaptation to ecological conditions outside the ancestral niche. The appearance of novel habitats caused by climatic oscillation can promote range expansion and accompanying demographic growth. The demographic dynamics of populations leave a signal in \ patterns. We modeled three competing scenarios pertaining to the circumstance of a range expansion by the Karoo Scrub-Robin into newly available habitat resulting from the increasing aridification of southern Africa. Genetic variation was contrasted with the theoretical expectations of a spatial range expansion, and compared with data of a putative adaptive trait. We infer that this bird likely colonized the arid zone, as a consequence of adaptive evolution in a small peripheral population, followed by an expansion with recurrent exchange of migrants with the ancestral populations.

15.
Behav Brain Res ; 232(2): 421-5, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22507301

RESUMO

The links between spatial behavior and hippocampal levels of synapsin I and phosphosynapsin I were assessed in normal rats and in the pyrithiamine-induced thiamine deficiency (PTD) rat model of Wernicke-Korsakoff's syndrome. Synapsin I tethers small synaptic vesicles to the actin cytoskeleton in a phosphorylation-dependent manner, is involved in neurotransmitter release and has been implicated in hippocampal-dependent learning. Positive correlations between spontaneous alternation behavior and hippocampal levels of both synapsin I and phosphorylated synapsin I were found in control rats. However, spontaneous alternation performance was impaired in PTD rats and was accompanied by a significant reduction (30%) in phosphorylated synapsin I. Furthermore, no correlations were observed between either form of synapsin I and behavior in PTD rats. These data suggest that successful spontaneous alternation performance is related to high levels of hippocampal synapsin I and phosphorylated synapsin I. These results not only support the previous findings that implicate impaired hippocampal neurotransmission in the spatial learning and memory deficits associated with thiamine deficiency, but also suggest a presynaptic mechanism.


Assuntos
Hipocampo/metabolismo , Síndrome de Korsakoff/metabolismo , Comportamento Espacial/fisiologia , Sinapsinas/metabolismo , Deficiência de Tiamina/metabolismo , Animais , Modelos Animais de Doenças , Síndrome de Korsakoff/induzido quimicamente , Síndrome de Korsakoff/fisiopatologia , Aprendizagem em Labirinto/fisiologia , Fosforilação , Ratos , Deficiência de Tiamina/fisiopatologia
16.
Evolution ; 65(12): 3499-514, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22133221

RESUMO

Gene flow is traditionally thought to be antagonistic to population differentiation and local adaptation. However, recent studies have demonstrated that local adaptation can proceed provided that selection is greater than the homogenizing effects of gene flow. We extend these initial studies by combining ecology (climate), phenotype (body size), physiological genetics (oxidative phosphorylation genes), and neutral loci (nuclear microsatellites and introns) to test whether selection can counter-balance gene flow and hence promote local adaptation in a bird whose distribution spans an aridity gradient. Our results show that the Karoo scrub-robin's climatic niche is spatially structured, providing the potential for local adaptation to develop. We found remarkably discordant patterns of divergence among mtDNA, morphology, and neutral loci. For the mitochondrial genes, two amino acid replacements, strong population structure and reduced gene flow were associated with the environmental gradient separating western coastal sites from the interior of southern Africa. In contrast, morphology and the neutral loci exhibited variation independent of environmental variables, and revealed extensive levels of gene flow across the aridity gradient, 50 times larger than the estimates for mitochondrial genes. Together, our results suggest that selective pressures on physiology, mediated by the mitochondrial genome, may well be a common mechanism for facilitating local adaptation to new climatic conditions.


Assuntos
Fluxo Gênico , Passeriformes/genética , Seleção Genética , Aclimatação/genética , Animais , Metabolismo Basal , Tamanho Corporal , Genoma Mitocondrial , Genótipo , Geografia , Repetições de Microssatélites , Fosforilação Oxidativa , Passeriformes/anatomia & histologia , Passeriformes/fisiologia , Fenótipo , Água/metabolismo
17.
Neuropsychiatr Dis Treat ; 7: 709-14, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22247612

RESUMO

BACKGROUND: Psychiatric symptoms during pregnancy induce an increase in morbidity and also in the mortality levels among women and children. However, the real association between pregnancy and psychiatric disorders and the peculiarities of the phenomenology of symptoms in underprivileged countryside communities remain uncertain. OBJECTIVE: To verify the association between psychiatric disorder, symptoms, and pregnancy among women from a low-income countryside community and to determine the specific cutoff points for major depression diagnosis according to Beck Depression Inventory for the different trimesters of pregnancy in this population. METHODS: Ninety-four pregnant women and 38 healthy women from the Conceição do Mato Dentro health service, a rural low-income community in Brazil, participated in the present study. Psychiatric examination included a structured clinical interview for psychiatric disorders according to Mini International Neuropsychiatric Interview and psychometric scales such as the Yale-Brown Obsessive Scale, the Beck Depression Inventory, and the Hamilton Anxiety Scale. The cutoff points for Beck Depression Inventory were determined through the application of receiver operating characteristic curves considering the diagnosis of major depression according to Mini International Neuropsychiatric Interview. RESULTS: The pregnant women had a higher frequency of psychiatric disorders and depression and anxiety symptoms. All cutoff points of Beck Depression Inventory were equal or higher than 12 with high sensitivity and specificity. Although the modified cutoff was selected based on both high sensitivity and high specificity, they were lower than when the cutoff was applied to nonpregnant women. CONCLUSION: Pregnancy was associated with the occurrence of psychiatric disorders and depressive and anxiety symptoms. In comparison to the literature, the present results indicate that there are different cutoff points in the Beck Depression Inventory for pregnant women from different cultures and in different pregnancy trimesters.

18.
Behav Brain Res ; 180(2): 226-34, 2007 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-17481744

RESUMO

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.


Assuntos
Envelhecimento/fisiologia , Consumo de Bebidas Alcoólicas/fisiopatologia , Extinção Psicológica/fisiologia , Ácido Hidroxi-Indolacético/metabolismo , Núcleos da Rafe/metabolismo , Serotonina/metabolismo , Análise de Variância , Animais , Comportamento Animal , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Química Encefálica/efeitos dos fármacos , Depressores do Sistema Nervoso Central/administração & dosagem , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Etanol/administração & dosagem , Extinção Psicológica/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/fisiologia , Núcleos da Rafe/efeitos dos fármacos , Ratos , Ratos Wistar
19.
Behav Brain Res ; 180(1): 102-6, 2007 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-17395279

RESUMO

The effects of chronic ethanol and thiamine deficiency, alone or associated, on hippocampal protein phosphorylation profiles ranging in molecular weight from 30 to 250kDa molecular weight, in stimulated (high K(+) concentration) and unstimulated (basal) conditions were investigated. These treatments significantly changed the phosphorylation level of an 86kDa phosphoprotein. Thiamine deficiency, but not chronic ethanol, induced a decrease in a behavioural extinction index, which is significantly correlated to the phosphorylation level of the p86 protein. These data add to and extend previous findings by our laboratory implicating the involvement of hippocampal neurotransmission components in extinction of a behaviour which involves learning of environmental spatial cues.


Assuntos
Extinção Psicológica/fisiologia , Hipocampo/metabolismo , Síndrome de Korsakoff/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Depressores do Sistema Nervoso Central/farmacologia , Modelos Animais de Doenças , Etanol/farmacologia , Masculino , Fosforilação , Ratos , Ratos Wistar , Deficiência de Tiamina/metabolismo
20.
Am J Physiol Heart Circ Physiol ; 293(1): H394-401, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17369466

RESUMO

Extensive work has been done regarding the impact of thiamine deprivation on the nervous system. In cardiac tissue, chronic thiamine deficiency is described to cause changes in the myocardium that can be associated with arrhythmias. However, compared with the brain, very little is known about the effects of thiamine deficiency on the heart. Thus this study was undertaken to explore whether thiamine deprivation has a role in cardiac arrhythmogenesis. We examined hearts isolated from thiamine-deprived and control rats. We measured heart rate, diastolic and systolic tension, and contraction and relaxation rates. Whole cell voltage clamp was performed in rat isolated cardiac myocytes to measure L-type Ca(2+) current. In addition, we investigated the global intracellular calcium transients by using confocal microscopy in the line-scan mode. The hearts from thiamine-deficient rats did not degenerate into ventricular fibrillation during 30 min of reperfusion after 15 min of coronary occlusion. The antiarrhythmogenic effects were characterized by the arrhythmia severity index. Our results suggest that hearts from thiamine-deficient rats did not experience irreversible arrhythmias. There was no change in L-type Ca(2+) current density. Inactivation kinetics of this current in Ca(2+)-buffered cells was retarded in thiamine-deficient cardiac myocytes. The global Ca(2+) release was significantly reduced in thiamine-deficient cardiac myocytes. The amplitude of caffeine-releasable Ca(2+) was lower in thiamine-deficient myocytes. In summary, we have found that thiamine deprivation attenuates the incidence and severity of postischemic arrhythmias, possibly through a mechanism involving a decrease in global Ca(2+) release.


Assuntos
Arritmias Cardíacas/fisiopatologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Deficiência de Tiamina/fisiopatologia , Tiamina/sangue , Animais , Arritmias Cardíacas/complicações , Arritmias Cardíacas/patologia , Traumatismo por Reperfusão Miocárdica/complicações , Traumatismo por Reperfusão Miocárdica/patologia , Ratos , Ratos Wistar , Deficiência de Tiamina/complicações , Deficiência de Tiamina/patologia
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