Equivalência de estímulos, um fenômeno comportamental amplamente demonstrado em humanos, tem sido encontrada com dificuldades em não-humanos, provavelmente devido a dificuldades de procedimento. Controle não programado pela posição dos estímulos tem sido apontado como um fator que interfere no desempenho de "matching-to-sample" e que leva a resultados negativos em testes de propriedades definidoras de equivalência (reflexividade, simetria e transitividade). Duas linhas de pesquisa foram exploradas: 1) Posição como estímulo em discriminações condicionais e testes de propriedades emergentes e 2) Treino e testes de relações condicionais na ausência de correlação entre a posição e a função dos estímulos. Foram conduzidos quatro experimentos com três macacos Cebus apella, uma fêmea e dois machos. No Experimento I, os sujeitos foram submetidos a treino de discriminações condicionais e testes de propriedades emergentes com posições como estímulo. Resultados positivos nos testes foram encontrados quando as relações testadas eram topograficamente semelhantes às relações treinadas. No Experimento II, treinos de discriminações simples com três conjuntos de estímulos visuais (cores e formas arbitrárias) mostraram diferenças na "discriminabilidade" dos estímulos. No Experimento III os sujeitos foram submetidos a treino de pareamento por identidade e testes de reflexividade com dois dos três conjuntos de estímulos facilmente discriminados no Experimento II e mais três novos conjuntos de estímulos. Os resultados dos testes foram positivos quando os estímulos já tinham sido apresentados antes em treinos de discriminações simples simultâneas, que possivelmente funcionaram como um treino de "matching-to-sample" com atraso. No Experimento IV os sujeitos foram submetidos a treinos de relações condicionais arbitrárias e a testes de simetria, cujos resultados foram negativos. Escolhas corretas foram reforçadas em todas as tentativas, em todos os experimentos. Todas as tentativas de "matching-to-sample" eram com atraso zero. A interpretação dos dados baseia-se na suposição de que relações de equivalência são relações ambientais. O pré-requisito para a emergência das propriedades definidoras é a aquisição de controle por essas propriedades enquanto relações ambientais, o que demanda extenso treino. / Stimulus equivalence, a largely demonstrated behavioral phenomenon in humans has been hardly found in non-humans likely due to procedural difficulties. Unprogrammed control by stimulus position has been pointed as interfering with matching-to-sample performances, which leads to negative results in tests of equivalence defining properties (reflexivity, symmetry and transitivity). Two lines of research were pursued that investigate: 1) Location as stimulus in conditional discriminations and tests of emergent properties and 2) Training and tests of conditional relations with no relation between location and function of stimuli. Four experiments with 1 female and 2 male Cebus apella were conducted. In Experiment I subjects were submitted to training of conditional discriminations and tests of emergent properties with location as stimulus, with positive results when the tested relations were similar to those trained. In Experiment II, training of simultaneous simple discriminations with three sets of visual stimuli (colors and arbitrary forms) showed differences in discriminability of the stimuli. In Experiment III, with two of the easily discriminated stimulus sets and three new stimulus sets, subjects received training of identity matching-to-sample and reflexivity tests, with positive results when the stimuli had been presented before in simultaneous simple discriminations, that possibly functioned as delayed identity matching-to-sample. In Experiment IV, subjects were submitted to arbitrary matching-to-sample training, and to symmetry tests with negative results. Correct choices in all trials were reinforced. All matching-to-sample trials were zero-delay. Interpretation of data relay on the assumption that equivalence relations are environmental relations. The prerequisite for defining properties emergence may be the acquisition of control by these defining properties as environmental relations, which demand extended training.

<p>For many years, primates have been considered to be animals with a poorly developed sense of smell. However, in recent years several studies have shown that at least some primate species have a high olfactory sensitivity for a variety of odorants. The present study used a two-choice instrumental conditioning paradigm to test the olfactory sensitivity for six aromatic aldehydes in four spider monkeys (Ateles geoffroyi). With helional, cyclamal,canthoxal and lilial all animals discriminated concentrations below 1 ppm from the odorless solvent, with single individuals even scoring better. With 3-phenyl-propionic aldehyde all animals detected concentrations below 2 ppb, and with bourgeonal even below 0.3 ppb. The detection thresholds of the odorants changed systematically with molecular structure. Addition of a dioxo or methoxy group to the benzene ring led to an increase in threshold values,while the absence of a methyl group close to the aldehyde moiety was linked to a low threshold value for the odorant. The study shows that spider monkeys have a well developed olfactory sensitivity for aromatic aldehydes.</p>

For many years, primates have been considered to be animals with a poorly developed sense of smell. However, in recent years several studies have shown that at least some primate species have a high olfactory sensitivity for a variety of odorants. The present study used a two-choice instrumental conditioning paradigm to test the olfactory sensitivity for six aromatic aldehydes in four spider monkeys (Ateles geoffroyi). With helional, cyclamal,canthoxal and lilial all animals discriminated concentrations below 1 ppm from the odorless solvent, with single individuals even scoring better. With 3-phenyl-propionic aldehyde all animals detected concentrations below 2 ppb, and with bourgeonal even below 0.3 ppb. The detection thresholds of the odorants changed systematically with molecular structure. Addition of a dioxo or methoxy group to the benzene ring led to an increase in threshold values,while the absence of a methyl group close to the aldehyde moiety was linked to a low threshold value for the odorant. The study shows that spider monkeys have a well developed olfactory sensitivity for aromatic aldehydes.

Humans are exceptional in their willingness to and frequency with which they help one another. However, nonhuman primates also exhibit prosocial behavior. Recently, a number of laboratory studies examining prosociality among primates have yielded conflicting results. These contradictory findings may be due to a reliance on human interaction, tokens, or interactions in the direct context of food, a highly valued resource for animals. The current study examined prosocial behavior among capuchin monkeys (Cebus apella) in a tool task designed to address these issues by examining whether capuchins would transfer a necessary tool to a partner in different payoff conditions. Some capuchins’ behavior indicated that they understood the task, passing the tool when a partner and food were present. Notably, tool transfer in both tasks was overwhelmingly active rather than passive, which is unusual in the context of food; indicating active prosocial behavior is present amongst primates other than cooperative breeders.

CD8+ T cells responses are critical in the immune defense against human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infection. A major challenge for vaccine development is that HIV/SIV can rapidly mutate to escape containment by the CD8+ T cell response. Therefore, optimal virus control by a vaccine will likely require clonally diverse CD8+ T cells capable of recognizing mutant viruses. Mucosal tissues play a fundamental role in early HIV/SIV pathogenesis by serving as the site for viral entry, CD4+ T cell depletion, and a reservoir for viral replication. Vaccine strategies that induce effective mucosal immunity will likely be critical for protection against HIV/SIV. We examined the SIV Gag p11C-specific CD8+ T cell responses in peripheral blood, gastrointestinal (GI) mucosal and lung mucosal tissues of rhesus monkeys expressing the MHC class I molecule Mamu-A*01. We first investigated the clonal composition of this cell population during the acute and chronic phases of SIVmac infection. We showed that there is a narrowing of the clonal repertoire from acute to chronic infection and the same clonal populations of virus-specific CD8+ T cells are present in the systemic and mucosal compartments of chronically SIV-infected animals. These data indicated that virus-specific CD8+ T cells establish broadly distributed immune responses. Next, we examined the clonal diversity of systemic and mucosal p11C-specific CD8+ T cells induced by prime-boost vaccination. We found that systemic prime-boost vaccination induced clonally diverse p11C-specific populations in mucosal tissues. There were high levels of clonal sharing between systemic and mucosal compartments soon after vaccination. However, later following vaccination there was decreased clonal sharing between the GI mucosa and the systemic circulation. We showed that this was due to limited trafficking of p11C-specific CD8+ T cells to the GI mucosa following vaccination. Overall, these studies indicate that following SIV infection and systemic vaccination the same p11C-specific clones are present in mucosal and systemic compartments. Moreover, the apparent immune compartmentalization is a consequence of differences in cell trafficking between systemic and mucosal CD8+ T cells. These observations have important implications for the design of HIV vaccines that generate effective mucosal immunity.

No description available.

Two approaches were taken to investigating constraints on kinship in predicting social behaviour in the vervet monkey Cercopithecus aethiops sabaeus in Barbados. in Chapter 1, behavioural interactions between an adult female and an unrelated adopted infant were compared with those between mothers and their natural offspring. The adoptive mother consistently scored higher than mothers with their own offspring in pre-weaning contact-maintaining behaviours, but the difference was not statistically significant. Post-weaning aggression and support interactions between mothers and infants also suggest no difference in parental behaviour and parental costs between adoptive and natural mothers. During post-weaning, the adopted infant was more aggressive to other troop members, and provided more maternal support in aggressive disputes, than another high ranking infant of the same year. / In Chapter 2, effects of kinship on the distribution of aggression and support in feral vervet monkeys were investigated by comparing aggression and support between full sibs and maternal half sibs (within matrilines), and between paternal-half sibs and unrelated juveniles (between matrilines). The strong tendency to behave affiliatively to matrilineal members in Old World monkeys, and maternal control of offspring rank within matrilines, may constrain the ability of offspring to enhance inclusive fitness by behaving differentially to either paternal or maternal sibs based on their degree of relatedness.

No description available.

This study examines the effect fallback foods, foods eaten when other, more preferred foods are scarce, have on the tool-using behaviors of capuchin monkeys. In the arid Serra da Capivara National Park in Brazil, black-striped capuchins (Cebus libidinosus) use stone tools to dig for underground tubers, a very rare behavior among primates. I test the hypothesis that the capuchins in the Serra da Capivara exploit tubers as a fallback food because palm nuts, an important fallback resource to other groups of capuchins living in arid environments, are either rare or absent there. Studies of floristic analysis at the park and other capuchin sites show that palm nut species recorded to be consumed by capuchins are not found at the Serra da Capivara. Additionally, nutritional analysis of both palms nuts and tubers suggest that tubers could act as a replacement for palm nuts as a fallback food. This may have relevance to human evolution, as several researchers suggest tubers and other underground storage organs were important resources to early hominins. / Department of Anthropology

Orientador: Cláudio Aparecido Casatti / Resumo: As teneurinas (TENs) representam uma família de proteínas transmembrana preservada entre as espécies, presente principalmente no sistema nervoso central (SNC). Nos vertebrados essa família é composta por quatro homólogos, denominados de teneurina-1 a -4 (Ten-1, Ten-2, Ten-3 e Ten-4). Estudos mostraram a presença das TENs em vias motoras, olfatórias e visuais, especialmente durante a neurogênese em aves e roedores. A análise da distribuição neuroanatômica das TENs em primatas poderia ampliar o conhecimento destas proteínas, contribuindo com achados funcionais recentes. Portanto, os propósitos deste estudo foram: 1) avaliar a distribuição dos neurônios que exibem imunorreatividade relacionada às TENs-“like immunoreactivity” (TENs-LI), em particular Ten-2-LI, Ten-3-LI e Ten-4-LI no SNC do primata não-humano (Sapajus spp); 2) realizar análise comparativa dos sítios de distribuição da proteína Ten-3 entre o SNC de primatas (Sapajus spp) e roedores (Rattus norvegicus), uma vez que a Ten-3 apresentou distribuição significante no SNC de primatas; 3) correlacionar a distribuição das TENs com seus ligantes endógenos denominados de latrofilinas (LPHNs-1, 2 e 3) em áreas do SNC de primatas. Para isso, cortes coronais do SNC de macacos (n=3) e de ratos (n=4) foram submetidos à técnica de imuno-histoquímica e analisados em microscopia de luz ou confocal. Os resultados demonstraram a distribuição de neurônios e fibras nervosas exibindo TENs-LI em todo o neuroeixo de primatas. Neurônios e... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Teneurins (TENs) represent a transmembrane protein family preserved along animal species, mainly in the central nervous system (CNS). This protein family is constituted by four homologues, named as teneurin 1 to 4 (Ten-1, Ten-2, Ten-3 and Ten-4). Previous studies pointed out presence of TENs in motor, olfactory and visual systems in chicken and rodents, especially during neurogenesis. The neuroanatomic distribution analysis of TENs in the primate brain could provide additional information on this protein system, as well as support functional data from recent studies. Therefore, the purposes of the present study were: 1) to evaluate the distribution of neurons exhibiting TENs-like immunoreactivity (TENs-LI), in particular, Ten- 2-LI, Ten-3-LI and Ten-4-LI in the CNS of non-human primates (Sapajus spp); 2) to comparatively analyze the main brain regions exhibiting Ten-3-LI between primates (Sapajus spp) and rodents (Rattus norvegicus), since Ten-3-LI showed significant distribution in the CNS of primates; 3) To correlate TENsLI neurons with latrophilins (LPHNs-1, 2 and 3), an endogenous TENs ligand, in the CNS of primates. For this purpose, coronal histological sections of the CNS of non-human primates (n=3) and rats (n=4) were submitted to immunohistochemistry techniques and analyzed under light or confocal microscopes. Neurons and nerve fibers exhibiting TENs-LI were observed in all parts of the CNS in primates. Neurons showing Ten-2-LI were present mainly in the brainstem, s... (Complete abstract click electronic access below) / Doutor