O Transtorno de Estresse Agudo (TEA) reúne o conjunto dos sintomas presentes nos indivíduos diante exposição a um evento traumático. A maneira como os indivíduos enfrentam os acontecimentos da vida está relacionada a vários fatores como as características de personalidade e ao estilo defensivo, ambos com uma importante influência no momento pós-trauma. O objetivo desta investigação foi pesquisar as caracteristicas de personalidade e o estilo defensivo em pacientes que sofreram trauma físico e desenvolveram TEA. O delinemeanto utilizado foi um estudo transversal controlado. A amostra foi por conveniência, composta por 18 pacientes com TEA e 42 pacientes sem TEA que sofreram trauma físico e necessitaram de internação em um Hospital referência em trauma em Porto Alegre, Rio Grande do Sul, Brasil. Os instrumentos utilizados foram um questionário estruturado, entrevista clínica, questionário de nível sócio econômico (NSE), questionário de Estilo Defensivo (DSQ), Bateria Fatorial de Peronalidade (BFP) e “The Mini-International Neuropsychiatric Interview” (M.I.N.I.). Resultados: Os dois grupos apresentarm uma distribuição homogênea em relação às variáveis clínicas e demográficas. Indivíduos com TEA apresentaram médias elevadas no fator de Neuroticismo da Bateria Fatorial de Personalidade, bem como nas sub-facetas de vulnerabilidade, instabilidade emocional e depressão. Em relação aos mecanismos defensivos foi demonstrado que a projeção, a agressão passiva, a atuação, o deslocamento, a cisão e a somatização podem estar relacionados a uma maior chance para o desenvolvimento de transtorno de estresse agudo em vítimas de trauma físico. Nesta amostra, os pacientes que desenvolveram transtorno de estresse agudo utilizaram mecanismos de defesas mais primitivos quando comparados aos indivíduos que não desenvolveram TEA. Além disso, são pessoas mais instáveis emocionalmente, apresentando um padrão de comportamento negativo em relação aos eventos cotidianos. / The Acute Stress Disorder (ASD) covers all the symptoms present in individuals before exposure to a traumatic event. The way individuals face the events of life is related to several factors such as personality characteristics and defensive style, both with an important influence in the post traumatic moment. The purpose of this research is to investigate the personality characteristics and defensive style in patients who have suffered physical trauma and developed ASD. The delimitation used was a controlled cross-sectional study. A convenience sample was used, consisting of 18 patients with ASD and 42 healthy who have suffered physical trauma and required admission to a referral hospital in trauma in Porto Alegre, Rio Grande do Sul, Brazil. The instruments used were a structured questionnaire, clinical interview, questionnaire (NSE), Defensive Style Questionnaire (DSQ), Factorial Personality Battery (BFP) and The Mini-International Neuropsychiatric Interview (MINI). Results: The two groups presented a homogeneous distribution in relation to clinical and demographic variables. Individuals with ASD had a high average in Neuroticism factor of Personality Factor Battery and the vulnerability of sub-facets, emotional instability and depression. In relation to the defensive mechanisms it has been shown that the projection, passive aggression, acting, displacement, division and somatization may be related to a greater chance for the development of acute stress disorder in physical trauma. In this sample, patients who developed acute stress disorder used more primitive defense mechanisms when compared to the patients without acute stress disorder. Besides that, they are more emotionally unstable people, having a negative pattern of behavior in relation to the daily events.

O Transtorno de Estresse Agudo (TEA) reúne o conjunto dos sintomas presentes nos indivíduos diante exposição a um evento traumático. A maneira como os indivíduos enfrentam os acontecimentos da vida está relacionada a vários fatores como as características de personalidade e ao estilo defensivo, ambos com uma importante influência no momento pós-trauma. O objetivo desta investigação foi pesquisar as caracteristicas de personalidade e o estilo defensivo em pacientes que sofreram trauma físico e desenvolveram TEA. O delinemeanto utilizado foi um estudo transversal controlado. A amostra foi por conveniência, composta por 18 pacientes com TEA e 42 pacientes sem TEA que sofreram trauma físico e necessitaram de internação em um Hospital referência em trauma em Porto Alegre, Rio Grande do Sul, Brasil. Os instrumentos utilizados foram um questionário estruturado, entrevista clínica, questionário de nível sócio econômico (NSE), questionário de Estilo Defensivo (DSQ), Bateria Fatorial de Peronalidade (BFP) e “The Mini-International Neuropsychiatric Interview” (M.I.N.I.). Resultados: Os dois grupos apresentarm uma distribuição homogênea em relação às variáveis clínicas e demográficas. Indivíduos com TEA apresentaram médias elevadas no fator de Neuroticismo da Bateria Fatorial de Personalidade, bem como nas sub-facetas de vulnerabilidade, instabilidade emocional e depressão. Em relação aos mecanismos defensivos foi demonstrado que a projeção, a agressão passiva, a atuação, o deslocamento, a cisão e a somatização podem estar relacionados a uma maior chance para o desenvolvimento de transtorno de estresse agudo em vítimas de trauma físico. Nesta amostra, os pacientes que desenvolveram transtorno de estresse agudo utilizaram mecanismos de defesas mais primitivos quando comparados aos indivíduos que não desenvolveram TEA. Além disso, são pessoas mais instáveis emocionalmente, apresentando um padrão de comportamento negativo em relação aos eventos cotidianos. / The Acute Stress Disorder (ASD) covers all the symptoms present in individuals before exposure to a traumatic event. The way individuals face the events of life is related to several factors such as personality characteristics and defensive style, both with an important influence in the post traumatic moment. The purpose of this research is to investigate the personality characteristics and defensive style in patients who have suffered physical trauma and developed ASD. The delimitation used was a controlled cross-sectional study. A convenience sample was used, consisting of 18 patients with ASD and 42 healthy who have suffered physical trauma and required admission to a referral hospital in trauma in Porto Alegre, Rio Grande do Sul, Brazil. The instruments used were a structured questionnaire, clinical interview, questionnaire (NSE), Defensive Style Questionnaire (DSQ), Factorial Personality Battery (BFP) and The Mini-International Neuropsychiatric Interview (MINI). Results: The two groups presented a homogeneous distribution in relation to clinical and demographic variables. Individuals with ASD had a high average in Neuroticism factor of Personality Factor Battery and the vulnerability of sub-facets, emotional instability and depression. In relation to the defensive mechanisms it has been shown that the projection, passive aggression, acting, displacement, division and somatization may be related to a greater chance for the development of acute stress disorder in physical trauma. In this sample, patients who developed acute stress disorder used more primitive defense mechanisms when compared to the patients without acute stress disorder. Besides that, they are more emotionally unstable people, having a negative pattern of behavior in relation to the daily events.

Nous avons évalué les conséquences sur un plan endocrinien et cognitif de l’administration d’un stress aigu chez la souris BalbC jeune (6 mois) ou d’âge moyen (16 mois). Le stress aigu a été appliqué 5, 60 ou 120 minutes avant la phase de rappel dans une épreuve de mémoire contextuelle. La concentration en corticostérone hippocampique a été mesurée avant et après le stress. Suite à l'administration du stress, elle augmente rapidement (dès 15 minutes post-stress) et est inversement liée au rappel mnésique. En effet, plus la concentration de corticostérone hippocampique est élevée, plus faible est la réponse hippocampe-dépendante. Les effets cognitif et endocrinien du stress ont été reproduits par l'administration de corticostérone dans l'hippocampe et ont été bloqués par la métyrapone. Le vieillissement accroit l’anxiété et induit des conséquences sur le plan mnésique comparable à celles du stress chez la souris jeune. De plus, la concentration de corticostérone hippocampique, basale ou en réponse au stress, est plus élevée et durable chez les animaux âgés, par rapport aux jeunes. Par ailleurs, l’administration de diazépam 30 minutes avant le rappel chez la souris d’âge-moyen atténue les effets délétères du stress sur la mémoire et la concentration hippocampique de corticostérone. Ces données suggèrent que la perturbation de l'axe HPA chez la souris âgée joue un rôle clef dans les troubles de mémoire hippocampe-dépendants induits par le vieillissement. / The cognitive and endocrinal consequences of an acute stress were studied in young (6 months) and middle-aged (16 months) BalbC mice. Acute stress was delivered 5, 60 or 120 minutes before the retrieval phase of a contextual memory task. Hippocampal corticosterone concentration was measured before and after stress delivery by microdialysis. The acute stress induces a rapid hippocampal corticosterone rise in relation with a cognitive impairment. Indeed, when the level of hippocampal corticosterone is high, the cognitive performance of hippocampal-dependent memory is impaired. Moreover, the cognitive and endocrinal effects of stress were mimicked using corticosterone microinjection in the hippocampus, whereas metyrapone (an inhibitor of corticosterone synthesis) blocked it. The consequences of aging on memory retrieval are similar to stress effects in young mice. Furthermore, pre and post-stress hippocampal corticosterone concentration is higher in middle-aged as compared to young mice. In addition, the increase in hippocampal corticosterone is longer in middle-aged in contrast to young mice. Finally, the administration of diazepam in middle-aged mice (30 minutes before the retrieval test phase) attenuates the deleterious effects of an acute stress on memory retrieval and the increase in hippocampal corticosterone concentration. In conclusion, our data suggest that HPA axis dysregulation, observed in middle-aged subjects, plays a key role in episodic-like memory impairments induced by aging.

Perceived job insecurity (JI) among employees is a common problem in our globalized economy that is characterized by competition and demands flexibility from both employees and employers. The existing literature presents a lot of evidence for the impact of JI on general physical health and psychological well-being outcomes, but asks for more longitudinal research on the impact of JI on specific outcomes, controlled for their baseline levels. The current study addresses this gap in existing research and investigates the associations between JI and diagnosed major depression, diagnosed acute stress, sleep quality, and the health-related behaviors of smoking and snussing in two Swedish samples from Stockholm and Norrland, over long time spans (up to 17 years for the Stockholm sub-sample). Data was obtained from the WOLF study. Results are mixed. For the Stockholm sub-sample, job insecurity correlates with most outcome measures except diagnosed stress, and predicts small shares of variance of sleep quality, the number of cigarettes participants smoke, and if participants use snus. The Norrland sub-sample replicates the impact of JI on general health and hints at a relationship between JI and sleep quality, but no other correlations with health-related behaviors or diagnoses were significant. Reasons for the differences among the sub-samples and limitations of the study are discussed.

Orientador: Percília Cardoso Giaquinto / Resumo: CAPÍTULO 1 – Neste estudo avaliamos o efeito do estresse agudo e crônico na memória de aprendizagem de tilápias-do-Nilo com diferentes perfis de personalidade. Inicialmente definimos a personalidade dos peixes através de testes de objeto novo e exposição a um predador, classificando-os em shy (tímido) ou bold (ousado) e em seguida estes indivíduos foram condicionados por um método simples de condicionamento clássico como forma de aprendizagem para posterior avaliação da memória. Os peixes shy foram então divididos em dois grupos, sendo que em um deles os peixes foram diariamente estressados por hipóxia, perseguição com rede ou confinamento (grupo shy-experimental) por 64 dias consecutivos, enquanto que no outro grupo os peixes permaneceram apenas isolados (grupo shy-controle) pelo mesmo período de tempo. O mesmo procedimento foi adotado com os peixes classificados como bold. Nesse mesmo período, testes de memória foram realizados em dias específicos, tanto nos grupos experimental quanto nos grupos controle. Ao final do experimento, reavaliamos se as personalidades se mantiveram. Obtivemos que o estresse agudo afetou a memória de aprendizado em peixes, principalmente em indivíduos com perfil de personalidade shy. CAPÍTULO 2 – Aqui desenvolvemos uma metodologia simples de condicionamento clássico facilmente aplicável em laboratórios de experimentação com peixes, quando comparados aos métodos descritos na literatura atual, onde os estímulos geralmente aplicados para condicioname... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: CHAPTER 1 - In this study we evaluated the effect of acute and chronic stress in learning memory of Nile tilapia with different personality profiles. Initially we defined the personality of the fish through the testo f new object and exposure to a predator, classifying them as shy or bold, and then these individuals were conditioned by a simple method of classical conditioning as a way of learning to evaluation of memory. The shy fish were divided into two groups, and in one group the fish were daily stressed by hypoxia, net chase or confinement (shy-experimental group) for 64 consecutive days, while in the other group the fish remained only isolated (shy-control group) for the same time period. The same procedure was adopted with fish classified as bold. During the same period, memory tests were performed on specific days, in both groups, experimental and control group. At the end of the experiment, we reevaluated whether the personalities held. We found that acute stress affected learning memory in fish, especially in individuals with shy personality profiles. CHAPTER 2 - Here we develop a classical conditioning methodology easily applicable in fish experimentation laboratories when compared to the methods described in the current literature, where the stimuli generally applied for conditioning (sound or light) can interfere with the responses of experimental animals present in the same laboratory. For this conditioning, we isolate the fish in individual aquariums and intro... (Complete abstract click electronic access below) / Doutor

The establishment of physiological norms for psychologically hardy vs. non-hardy individuals was attempted by examination of levels of salivary cortisol and urinary norepinephrine before and after a mid-term examination stressor. Normative data was collected on the reported frequency of stressors and their severity one week prior to the examination, and self-reported ratings of stress immediately prior to the examination. Performance on the examination as a function of hardiness was explored. Associations between demographic variables and psychological hardiness were also studied. Results from this study were inconclusive in establishing physiological norms for psychologically hardy individuals. Associations were found between: 1) hardiness and frequency of stressors; 2) hardiness and age; and 3) self-reported ratings of stress and anxiety as measured by the State-Trait Anxiety Inventory (STAI).

When humans are faced with multiple options, they must decide whether to choose a novel or less certain option (explore) or stick with what they know (exploit). Exploration is a fundamental cognitive process. Importantly, when humans attempt to solve the explore-exploit dilemma, they must effectively incorporate both feedback and uncertainty to guide their actions. While prior work has shown that both acute (short-term) and chronic (long-term) stress can disrupt how humans solve the explore-exploit dilemma, the mechanisms of how this occurs are unclear. For example, does stress disrupt how people integrate feedback to guide their decisions to explore or exploit, or does stress disrupt computations of uncertainty regarding their choices? Importantly, the use of electroencephalography as a tool can help reveal the impact of stress on explore-exploit decision making by measuring neural signals sensitive to feedback learning and uncertainty. In the present dissertation, I provide evidence from a series of experiments where I examined the impact of both acute and chronic stress on the explore-exploit dilemma while electroencephalographic data was collected. In experiment 1, I exposed participants to an acute stressor and then examined their decisions to switch or stay – as a proxy for explore and exploit decisions – in a multi-arm bandit paradigm. I found tentative evidence that the acute stress response disrupted both the feedback learning signal (the reward positivity) and the uncertainty signal (the switch P300). In experiment 2 I adopted a computational neuroscience approach and directly classified participants decisions as explorations or exploitations using reinforcement learning models. There was only an effect of the acute stress response on feedback signals, in this case, the feedback P300. In experiments 1 and 2, I used contextual bandit tasks where the reward probabilities of the options shifted throughout, and there was no behavioural effect of acute stress on task performance or exploration rate. However, in experiment 3, I examined a learnable bandit where one option was preferred. Again, using computational modelling and electroencephalography, I found tentative evidence that the acute stress response disrupted the feedback learning signals (the feedback P300) and stronger evidence that acute stress disrupted the uncertainty signal (the exploration P300). As well, I observed that the acute stress response reduced task performance and increased exploration rate. Lastly, in experiment 4, I examined the impact of chronic stress exposure on explore-exploit decision making and electrophysiology – while I found no effects of chronic stress, I believe future research is necessary. Taken together, these findings provide novel evidence for the neural mechanisms of how the acute stress response impacts the explore-exploit dilemma through disruptions to feedback learning and assessments of uncertainty. These findings also highlight how theories of the P300 signal may not be properly capturing the varied role of the P300 in cognition. / Graduate

The prenatal environment has been shown to have lasting effects on cardiovascular health. In the present study, pregnant rats were fed a 0.7% NaCl normal salt (NS) diet or an 8% NaCl high salt (HS) diet throughout pregnancy. Adult offspring were fitted with radiotelemetry probes to continuously measure blood pressure and heart rate. Rats were placed in restraining cages to test for a programmed acute stress hyperresponsiveness. Offspring were challenged with HS diet for one week to determine if blood pressure salt sensitivity had been programmed by the prenatal HS diet. Animals were killed following resting and acute stress conditions, after which brains and blood were collected for in situ hybridization for corticotropin releasing hormone (CRH) and radioimmunoassay for corticosterone. In order to determine the contribution of gene expression to differences seen, total brain RNA was analyzed with microarray. Rats were injected with a ganglionic blocker and an adrenergic receptor antagonist before restraint to examine the autonomic component of the stress response. High salt offspring of either sex did not have basal hypertension. Female HS offspring had an increased pressor and tachycardic response to acute stress compared with NS females. There were no differences between male NS and HS offspring during acute stress. Salt sensitivity was not induced during high salt challenge. According to the microarray, 11 genes were upregulated and 10 were downregulated in adult brains, while 17 were upregulated and 17 were downregulated in pup brains. These data indicate that there are long-term changes due to HS diet. CRH levels were higher in the paraventricular nucleus (PVN) of female HS offspring than in female NS offspring during both basal and stressed conditions, though no differences were seen in CRH expression levels of male offspring. Autonomic blockade completely abolished the enhanced tachycardic response seen in female HS offspring. However, a difference in NS and HS blood pressures remained. Thus, female offspring of mothers fed an 8% NaCl diet have alterations in cardiovascular control, indicated by an enhanced tachycardic response as adults, due to changes in the autonomic nervous system, and enhanced pressor response to stress mediated by unknown mechanisms.

This is a quality improvement project that focuses on implementing screening for acute stress disorder using the Acute Stress Disorder Structured Interview–DSM-IV tool in a Trauma Intensive Care Unit (ICU) at a Level 2 Trauma Center in Nashville, TN. Currently, at this hospital there is not a screening process implemented for these patients. Every trauma patient meets the criteria for acute stress disorder. Starting the process early aims for patients to be properly educated about their trauma and gets them the resources they need to heal mentally from the trauma. During the 6-week implementation period of this project, the trauma performance investigator (TPI) team screens patients for acute stress disorder. The team records how many patients screened, how many patients were available to screen, if they screened positive with a 9 or greater score, if they received a “telepysch” visit, and if a referral card for mental health visit after discharge was given. From this information, it will be determined how to continue to improve the implementation process. Information gathered data by the TPI will be recorded in Excel spreadsheets. The ASD screening tool scores will be used to compare the mechanism of injury to the score to determine if a correlation exists. Some patients that do not screen positive still want a referral card due to the education provided during the screening process. This shows the continued need for patient screening and education about acute stress disorder for this patient population.

The immune response is a complex series of cell-mediated reactions by which an organism combats infection, responds to injury, external stresses, or disease. In both Drosophila melanogaster and vertebrates, aging is associated with progressive declines in physiological functions as well as susceptibility to stress and disease. Naturally, the immune activity is increased with age, yet the efficacy of this response is reduced with age. Conversely, when the immune activation is artificially-induced by Lipopolysaccharide, aging is accelerated. Like aging, neurodegeneration is also associated with increased immune activity. The Blood-Brain barrier (BBB) is a physical barrier with highly selective permeability that isolates the brain from the rest of the body. This barrier is essential for ion homeostasis, and exclusion or efflux of exogenous chemicals. The exclusion properties of the Dm BBB are facilitated by paracellular septate junctions of subperineural glia (SPG), which prevent diffusion into or out of the brain. Using the GAL/UAS system in Drosophila, we found that activation of a glial-specific immune response in either immunodeficiency (IMD) or Toll pathways led to reductions in lifespan and age-dependent negative geotaxis. These reductions were also correlated with an early sensitivity towards oxidative and thermal stresses. Furthermore, we found that a SPG-specific immune response of the Toll pathway or disruption of the paracellular BBB itself was sufficient to show the same reductions as pan-glial activation. In short, we found that flies with CNS-specific immune activation showed an inability to cope with long-term and acute forms of stress, and that SPG-specific Toll Activation was sufficient to show these effects. This implicates chronic immune response as a negative factor during aging, neurodegenerative disease, and brain homeostasis. / Thesis / Master of Science (MSc)