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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
251

A Single Neonatal Injury Induces Life-Long Adaptations In Stress And Pain Responsiveness

Victoria, Nicole C 27 August 2013 (has links)
Approximately 1 in 6 infants are born prematurely each year. Typically, these infants spend 25 days in the Neonatal Intensive Care Unit (NICU) where they experience 10-18 painful and inflammatory procedures each day. Remarkably, pre-emptive analgesics and/or anesthesia are administered less than 30% of the time. Unalleviated pain during the perinatal period is associated with permanent decreases in pain sensitivity, blunted cortisol responses and high rates of neuropsychiatric disorders. To date, the mechanism(s) by which these long-term changes in stress and pain behavior occur, and whether such alterations can be prevented by appropriate analgesia at the time of injury, remains unclear. We have previously reported in rats that inflammation experienced on the day of birth permanently upregulates central opioid tone, resulting in a significant reduction in adult pain sensitivity. However, the impact on early life pain on anxiety- and stress-related behavior and HPA axis regulation is not known. Therefore the goal of this dissertation was to determine the long-term impact of a single neonatal inflammatory pain experience on adult anxiety- and stress-related responses. Neuroanatomical changes in stress-associated neurocircuits were also examined. As the endogenous pain control system and HPA axis are in a state of exaggerated developmental plasticity early in postnatal life, and these systems work in concert to respond to noxious or aversive stimuli, this dissertation research aimed to answer the following questions: (1) Does neonatal injury produce deficits in adult stress-related behavior and alter stress-related neuroanatomy through an opioid-dependent mechanism? (2) Does neonatal injury alter receptor systems regulating the activation and termination of the stress response in adulthood? (3) Are stress- and pain-related neurotransmitters altered within the first week following early life pain? (4) Is early activation of the pain system necessary for the long-term changes in anxiety- and stress-related behavior? Together these studies demonstrate the degree, severity and preventability of the long-term deficits in stress responding associated with a single painful experience early in life. The goal of this research is to promote change in the treatment of infant pain in the NICU to reduce long-term sensory and mental health complications associated with prematurity.
252

Effet d'un stress prolongé sur les capacités de mémorisation et les comportements de coopération chez le diamant mandarin (Taeniopygia guttata)

Larose, Karine January 2009 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
253

Parental effort in the Northern Flicker (Colaptes auratus) and the trade-off between quantity and quality of offspring

2014 September 1900 (has links)
The two main goals of my thesis were to further our understanding of how parental effort is related to life-history trade-offs and to see how parental investment is reflected in various potential measures of nestling quality. I looked at how fitness is maximized by examining (1) the trade-off between current and future reproduction, and (2) the trade-off between quantity and quality of offspring. To see how parents responded to energetic demands and whether each sex reacted in a similar way, I experimentally manipulated brood sizes and quantified provisioning rates. Both male and female parents with enlarged broods increased their feeding rates, but provisioning on a per nestling basis declined, so that parents fledged lighter nestlings with shorter wings. Although the incidence of mortality did not differ between control and enlarged broods, nestlings from enlarged broods were lighter than those from control broods with the same brood size, suggesting that clutch size may be individually optimized. I also looked at how nestlings responded to different levels of nutritional stress in the manipulated broods by quantifying size and body condition, plumage colouration, and the physiological measures of T-cell mediated immune responses, and corticosterone levels in nestling feathers as a long-term integrated measure of stress physiology. The size of melanin ornaments on feathers and the saturation and brightness of carotenoid colouration was associated with nestling mass in such a way that suggested that plumage characteristics reflect nestling quality. The immune function of nestlings was negatively related to brood size and nestlings in better body condition could mount greater immune responses to foreign antigens suggesting that immune responses are energetically costly. Corticosterone levels in the feathers were not related to nestling body condition and were unaffected by the experimental brood manipulation. The ii mass of male nestlings, which are the larger sex, was more compromised by brood size than female mass was. I also found sex-specific relationships between plumage characteristics and measures of physiological performance. These findings help to explain optimal clutch size and the classic trade-off between quality and quantity of offspring. They also offer new insights into the reliability of putative measures of quality in nestlings and relationships between physiological and morphological traits.
254

The role of monoamines in post traumatic stress disorder (PTSD) using a time dependent sensitization animal model / Zakkiyya Igbal Jeeva

Jeeva, Zakkiyya Igbal January 2004 (has links)
Posttraumatic stress disorder (PTSD) is an anxiety disorder that may result from an exposure to a severely traumatic life-event. It is characterised by a delayed onset of psychological and physical symptoms including re-experiencing the event, avoidance of reminders associated with the trauma, increased autonomic arousal and distinct memory deficits. This disorder is also characterised by a maladaptive hypothalamic-pituitary-adrenal (HPA)-axis response and altered monoamine concentrations in the hippocampus and pre-frontal cortex. The Time Dependent Sensitization (TDS) model is a putative animal model of PTSD that is based on the concept of repeated trauma, using three acute stressors (TS) of intense severity followed by a mild situational reminder (RS) on day 7 subsequent to the acute stressors. The aims of this study were to determine if the Triple Stressor (TS) induces stress and if the situational reminder (RS) is necessary for the maintenance of the stress response over time and whether these two stress responses are qualitatively and quantitively different. This was done to further validate the TDS model and to characterize the development and progression of the stress-related pathology of PTSD. Methods used were High Performance Liquid Chromatography (HPLC) with electrochemical detection (biochemical correlates) for quantifying the monoamines dopamine (DA), noradrenaline (NA) and serotonin (5-HT) concentrations in the hippocampus and pre-frontal cortex (PFC); radio immuno assay (RIA) for the determination of plasma corticosterone concentrations (neuroendocrine parameter) and the use of the Elevated Plus Maze (EPM) to detect anxiety-like behaviour (behavioural analyses). The study was subdivided into an Acute and Re-Stress study (n = 10). In the Acute Study rats were exposed to TS as the only stressor. Group 1 was sacrificed immediately after TS, Group 2 was sacrificed 3 days post TS and Group 3 on day 7 post TS. In the Re-Stress Study both TS and RS were used as stressors. Group 4 was sacrificed immediately after the situational reminder, Group 5 was sacrificed 3 days post RS and Group 6 on day 7 post RS. A group of unstressed rats were used as Control. The results of this study found corticosterone concentrations elevated immediately after the TS (p<0.05). Exposure to the RS resulted in a profound hypocortisolism (p<0.05). These results indicate a possible disturbance in the regulation of the HPA-axis, which manifests as an enhanced negative feed-back upon re-introduction of the stressful situation. Changes in MA concentrations were evident. Although no definite fixed trend is apparent in this study, it is evident that the TDS model does induce monoamine dysregulation. Hippocampal NA. DA and 5-HT concentrations were noted to be elevated on day 7 post TS (p<0.05). On day 7 post RS only hippocampal 5HT was decreased significantly (p<0.05). Behavioural analyses indicate that stress related anxiety was not sustained after the TS but 7 days after the exposure to the RS rats were most anxious (p<0.05). The results confirm that the TDS model does induce PTSD-like symptoms in rats and that the situational reminder (RS) is necessary for the maintenance of the stress response. This model may be useful in the investigation of future experimental pharmacological interventions in the management of PTSD. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2005.
255

Dynamics of disease : origins and ecology of avian cholera in the eastern Canadian arctic

2015 October 1900 (has links)
Avian cholera, caused by infection with Pasteurella multocida, is an important infectious disease of wild birds in North America Since it was first confirmed in 2005, annual outbreaks of avian cholera have had a dramatic effect on common eiders on East Bay Island, Nunavut, one of the largest breeding colonies of northern common eiders (Somateria mollissima borealis) in the eastern Arctic. I investigated potential avian and environmental reservoirs of P. multocida on East Bay Island and other locations in the eastern Canadian Arctic by collecting cloacal and oral swabs from live or harvested, apparently healthy, common eiders, lesser snow geese, Ross’s geese, king eiders, herring gulls, and snow buntings. Water and sediment from ponds on East Bay Island were sampled before and during outbreaks. Avian and environmental samples were tested using a real-time polymerase chain reaction (PCR) assay to detect P. multocida. PCR positive birds were found in every species except for snow buntings, and PCR positive common eiders were found in most locations, supporting the hypothesis that apparently healthy wild birds can act as a reservoir for avian cholera. In all years, P. multocida DNA was detected in ponds both before and after the avian cholera outbreak began each year, suggesting that the environment also plays a role in outbreak dynamics. Contrary to our expectations, model results revealed that ponds were generally more likely to be positive earlier in the season, before the outbreaks began. Whereas average air temperature at the beginning of the breeding season was not an important predictor for detecting P. multocida in ponds, eiders were more likely to be PCR positive under cooler conditions, pointing to an important link between disease and weather. Potential origins of P. multocida causing avian cholera in Arctic eider colonies were investigated by comparing eastern Arctic isolates of P. multocida to isolates from wild birds across Canada, and the central flyway in the United States. Using repetitive extragenic palindromic-PCR (REP-PCR) and multi-locus sequence typing (MLST), we detected a low degree of genetic diversity among isolates, and P. multocida genotypes were correlated with somatic serotype. Isolates from East Bay Island were distinct from P. multocida from eider colonies in the St. Lawrence Estuary, Quebec, however, East Bay Island isolates were indistinguishable from isolates collected from a 2007 pelagic avian cholera outbreak on the east coast of Canada. Isolates from East Bay Island and Nunavik shared sequence types, indicating possible transmission of isolates among eider colonies in the eastern Arctic. Previously, feather corticosterone in eiders was found to be significantly associated with environmental temperature during the moulting period. In my study, path analysis revealed that environmental conditions experienced during the moulting period had direct impacts on arrival date and pre-breeding body condition of common eiders during the subsequent breeding period on East Bay Island, with indirect impacts on both reproductive success and survival. Higher temperatures experienced during the fall moulting period appear to impose significant costs to eiders, with subsequent carry-over effects on both survival and reproduction many months later during avian cholera outbreaks. This thesis describes several important features of the host, agent and environmental dynamics of avian cholera in North America with a particular focus on the disease in the eastern Canadian Arctic. Continued exploration of infectious wildlife disease dynamics is needed to better predict, detect, manage, and mitigate disease emergence that can threaten human and animal health and species conservation.
256

Efeito da superalimentação neonatal sobre a função adrenal e o desenvolvimento da microesteatose hepática em ratos adultos / Early overfeeding effect on adrenal function and development of mictoleatasis in adults rats

Ellen Paula Santos da Conceição 27 February 2012 (has links)
Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro / O estado nutricional e hormonal em fases iniciais de desenvolvimento (gestação e lactação) está relacionado a alterações epigenéticas, que podem levar ao desenvolvimento de doenças. A obesidade infantil está relacionada com a ocorrência da obesidade na idade adulta, resistência à insulina e maior risco cardiometabólico. Em estudos experimentais, a superalimentação neonatal causa obesidade e aumenta o risco de doenças cardiovasculares. Estes animais apresentam obesidade visceral, hiperfagia, hiperleptinemia e hipertensão na idade adulta. Previamente, demonstramos que a hiperleptinemia neonatal causa hiperfunção da medula adrenal e microesteatose na idade adulta. No presente estudo avaliamos a função adrenal de ratos adultos obesos no modelo de superalimentação neonatal por redução do tamanho da ninhada e a sensibilidade as catecolaminas no tecido adiposo visceral (TAV) e no fígado. Ao nascimento todas as ninhadas tiveram seu número de filhotes ajustados para 10. Para induzir a superalimentação neonatal, o tamanho da ninhada foi reduzido de dez para três filhotes machos no terceiro dia de lactação até o desmame (SA), enquanto que o grupo controle permaneceu com 10 filhotes durante toda a lactação. Após o desmame, os ratos tiveram livre acesso à dieta padrão e água até 180 dias (1 animal de cada ninhada, n = 7). O TAV e as glândulas adrenais foram pesadas. As contrações hormonais séricas, o conteúdo hepático de glicogênio e triglicerídeos foram avaliados por kits comerciais. O conteúdo e a secreção de catecolaminas adrenais foram avaliados utilizando o método do trihidroxindol. O conteúdo dos hormônios eixo hipotálamo-hipófise-córtex adrenal, das enzimas da via de síntese das catecolaminas na glândula adrenal, ADRB2 no fígado e ADRB3 no TAV foram determinados por Western blotting ou imunohistoquímica. As diferenças foram consideradas significativas quando p <0,05. Aos 180 dias de vida, o grupo SA apresentou maior massa corporal (+15%), maior consumo alimentar (+15%) e maior adiposidade visceral (+79%). Os hormônios do eixo hipotálamo-hipófise-córtex-adrenal não foram alterados. O grupo SA apresentou maior expressão de tirosina hidroxilase e de DOPA descarboxilase (+31% e 90%, respectivamente); conteúdo de catecolaminas adrenais (absoluta: 35% e relativa: 40%), e secreção de catecolaminas, tanto basal quanto estimulada por cafeína (+35% e 43%, respectivamente). O conteúdo ADRB3 no TAV não foi alterado nos grupo SA, entretanto o ADRB2 no fígado apresentou-se menor (-45%). O grupo SA apresentou maior conteúdo de glicogênio e triglicerídeos no fígado (+79% e +49%, respectivamente), além de microesteatose. A superalimentação neonatal resulta em hiperativação adrenomedular e aparentemente está associada a preservação da sensibilidade às catecolaminas no VAT. Adicionalmente sugerimos que o maior conteúdo de glicogênio e triglicerídeos hepático seja devido a menor sensibilidade as catecolaminas. Tal perfil pode contribuir para a disfunção metabólica hepática e hipertensão arterial que são características deste modelo de obesidade programada. / Nutritional and hormonal status at early phases of development are related to epigenetic changes, promoting disease development. Childhood overweight is related with late obesity, insulin resistance and higher cardiometabolic risk. Rats overfed during lactation show higher visceral adiposity, hyperphagia, leptin resistance and hypertension in adulthood. Previously, we demonstrated that neonatal hyperleptinemia is associated with adrenal medullary hyperfunction and liver steatosis at adulthood. Here, we evaluated the adrenal function and liver tissue of adult obese rats that were overfed during lactation. To induce early overfeeding, the litter size was reduced from ten to three male pups at the third day of lactation until weaning (SL). Control group had ten rats per litter (NL). After weaning, rats had free access to standard diet and water until 180 days old (1 animal from each litter, n=7). Significant differences had p<0.05. The SL group presented higher adrenal catecholamine content (absolute: +35% and relative: +40%), tyrosine hydroxylase (+31%), DOPA decarboxylase (+90%) protein contents, basal and caffeine-induced catecholamine in vitro secretion (+35% and +43%, respectively). However, hormones of the hypothalamic-pituitary-adrenal cortex axis were unchanged. The &#946;3-adrenergic receptor content in visceral adipose tissue was unchanged in SL rats, but the &#946;2-adrenergic receptor in the liver was lower (-45%). SL group showed higher glycogen and triglycerides contents in liver (+79% and +49%, respectively), which showed microesteatosis. Although the neonatal overfeeding leads to higher adrenomedullary function, adult obese SL rats have a dysfunction in hepatic &#946;2-adrenergic receptor, which can contribute for the hepatic dysfunction characteristic of liver obesity complications.
257

Provocação social na díade mãe-filhote: efeitos da ontogenia no comportamento social da prole

Henriques, Thiago Pereira January 2014 (has links)
As duas primeiras semanas de vida em ratos são críticas para o desenvolvimento, pois os animais são suscetíveis a influências ambientais. Diversos parâmetros neuroendócrinos e comportamentais podem ser influenciados, a curto e a longo prazo, pelas interações com a mãe, assim como por estressores. Entre esses estressores, um ambiente precoce socialmente aversivo pode alterar os comportamentos sociais, a ansiedade e as respostas neuroendócrinas ao estresse em adultos. O foco deste trabalho foi investigar o impacto do paradigma de provocação social na díade mãe-filhote sobre os comportamentos sociais e as respostas hormonais da prole em três idades. A provocação social foi realizada nos dias pós-natais (PP) 2 e 5. O comportamento maternal das lactantes foi registrado em PP3, 4, e 6. Os filhotes foram submetidos ao teste de preferência olfatória em PP7, o comportamento de brincadeira em juvenis foi registrado em PP30 e os ratos adultos (a partir de PP80) foram submetidos aos testes de campo aberto, labirinto em cruz elevado e interação social. Os adultos também foram expostos ao estresse por contenção (PP90). Os resultados mostraram que a intervenção aumentou a presença das mães no ninho. A intervenção reduziu o tempo gasto pelos filhotes no lado da maravalha do ninho, reduziu os níveis plasmáticos de ocitocina e prolactina, porém, aumentou os níveis de arginina-vasopressina. Nos juvenis, a intervenção reduziu a brincadeira de luta e os níveis plasmáticos de arginina-vasopressina. Nos adultos, a intervenção não levou a alterações na ansiedade e nas respostas hormonais ao estresse, porém, reduziu a latência para os comportamentos agressivos e os níveis plasmáticos basais de ocitocina. Conforme observado nas lactantes e nos neonatos, a provocação social levou a uma alteração da relação mãe-filhote, afetando, também, hormônios relacionados ao comportamento afiliativo em neonatos. Da mesma forma, a redução da brincadeira de luta em juvenis expostos à intervenção neonatal pode ter ocorrido devido à alteração da argininavasopressina, hormônio envolvido nesse comportamento. Apesar da intervenção não ter alterado a ansiedade e as respostas hormonais ao estresse em adultos, afetou de maneira específica o comportamento agressivo, reduzindo a sua latência. Este achado pode ser relacionado à ocitocina diminuída, conhecida por ter efeitos antiagressivos. Logo, sugerimos que a provocação social altere, tanto de forma precoce quanto duradoura, os comportamentos sociais, assim como os hormônios responsáveis pela modulação desses parâmetros. / The first two weeks of life in rats are critical for development because the animals are susceptible to environmental influences. A variety of neuroendocrine and behavioral parameters may be influenced in a short or long lasting way by the interactions with the mother as well as by stressors. Among these stressors, a socially aversive environment may alter social behaviors, anxiety and neuroendocrine responses to stress in adult subjects. The focus of this work was to investigate the impact of the social instigation paradigm on motherlitter dyad over social behaviors and hormonal responses in rats at 3 ages. Social instigation was carried out at postpartum days (PP) 2 and 5. Maternal behavior from lactating rats was registered at PP3, 4 and 6. Pups were submitted to the nest odor preference test at PP7, play behavior was registered in juveniles at PP30, and adult rats (starting at PP80) were submitted to the open field, elevated plus maze and social interaction tests. Adult rats were also submitted to restraint stress. Results show that the intervention increased presence in nest of lactating rats. The intervention reduced time spent on nest bedding side in pups, decreased oxytocin and prolactin plasma levels, however, increased arginine-vasopressin levels. Juveniles submitted to the neonatal intervention had reduced play-fighting frequencies and arginine-vasopressin levels. In adults, the intervention has not altered anxiety and hormonal responses to stress, however, it decreased the latency for aggressive behaviors, as well as oxytocin basal levels. According to the outcomes observed in lactating rats and pups, social instigation altered mother-infant relationship, as well as levels of hormones involved in affiliative behavior in neonatal rats. Similarly, the reduced play-fighting in juveniles exposed to the intervention may be related to the decreased arginine-vasopressin levels, which is a hormone involved in such behavior. In spite of the intervention having not altered the anxiety and hormonal responses to stress in adult rats, it altered in a specific manner the aggressive behavior, reducing its latency. This finding may be related to the decreased oxytocin levels, which is a hormone known to have antiaggressive effects. Thus, we suggest that social instigation impairs early to late social behaviors, as well as the hormones responsible for the modulation of such parameters.
258

Efeito benéfico do enriquecimento ambiental sobre o déficit de memória e a plasticidade celular hipocampal em ratos diabéticos tipo 1

Piazza, Francele Valente January 2012 (has links)
O diabetes mellitus tipo 1 (DMT1) tem sido associado com complicações a longo prazo no sistema nervoso central, além dos efeitos periféricos comuns relacionados à doença, causando disfunções cognitivas no encéfalo. Por outro lado, o enriquecimento ambiental (EA) induz mecanismos de plasticidade dependentes da experiência, especialmente no hipocampo, melhorando o desempenho dos animais em testes de aprendizado e memória. Assim, nosso objetivo foi avaliar a influência do EA sobre o déficit de memória, a atividade locomotora, os níveis de corticosterona, a imunorreatividade da proteína sinaptofisina, e a densidade e a ativação de astrócitos e microglia no giro denteado (GD) do hipocampo de ratos diabéticos tipo 1. Para isso, ratos Wistar machos com 21 dias de idade, foram expostos ao EA ou mantidos em caixamoradia padrão (controles, C) por 3 meses. Quando adultos, os animais tanto C quanto EA foram randomicamente divididos e induziu-se diabetes através de injeção de estreptozotocina em metade dos animais de cada grupo, sendo mantidas as respectivas condições ambientais para cada um dos grupos. A memória espacial dependente de hipocampo foi avaliada em todos os grupos através do teste de reconhecimento de objeto reposicionado, no 41o dia após a indução do diabetes, bem como a locomoção geral dos animais no campo aberto durante o mesmo teste. Os níveis séricos de corticosterona foram medidos ao final do experimento, a imunorreatividade da sinaptofisina foi avaliada por imunoistoquímica, e a densidade e a ativação de astrócitos e da microglia por imunofluorescência no hilo do GD do hipocampo. Nossos resultados mostraram que o EA foi capaz de prevenir ou atrasar o desenvolvimento do déficit de memória causado pelo diabetes em ratos, porém não reverteu o déficit motor observado nos animais diabéticos. Não houve diferença significativa na imunorreatividade da sinaptofisina entre os grupos. Além disso, embora o EA não tenha modificado a densidade e a ativação dos astrócitos nos animais diabéticos, o enriquecimento atenuou os efeitos prejudiciais da hiperglicemia sobre a ativação microglial, bem como reduziu os níveis séricos de corticosterona nos ratos diabéticos adultos. Assim, o EA ajudou a amenizar as comorbidades cognitivas associadas ao diabetes, possivelmente por atenuar a hiperatividade do eixo HPA e a ativação microglial nos animais diabéticos. / Type 1 diabetes mellitus (T1DM) has been associated with long-term complications in central nervous system, besides peripheral common adverse effects, causing neurocognitive dysfunction in the brain. On the other hand, enriched environment (EE) induces mechanisms of experiencedependent plasticity especially in hippocampus, improving the performance of animals in learning and memory tasks. Thus, our objective was to investigate the influence of the EE on memory deficits, locomotion, corticosterone levels, synaptophysin protein immunoreactivity, and density and activation of astrocytes and microglia in the hippocampal dentate gyrus (DG) of type 1 diabetic rats. For this, male Wistar rats, 21 days old, were exposed to the EE or maintained in standard housing (controls, C) for 3 months. At adulthood, C and EE animals were randomly divided and half of them induced to diabetes by streptozotocin, being maintained the respective environmental conditions for each animal groups. Hippocampus-dependent spatial memory was evaluated in all groups in the novel object-placement recognition task, on 41th day after diabetes induction, as well as the general locomotion in the open field at the same test. Serum corticosterone levels were measured in the end of the experiment, contents of synaptophysin was evaluated by immunohistochemistry, and density and activation of both astrocytes and microglia by immunofluorescence in the hilus of the DG in hippocampus. Our results showed that EE was able to prevent or delay the development of memory deficits caused by diabetes in rats, however did not revert the motor impairment observed in group diabetic. There was no significant difference in synaptophysin immunoreactivity among the groups. Furthermore, although the EE did not modify the density and activation of astrocytes in diabetic animals, it attenuated the injurious effect of hyperglycemia over microglial activation, as well as decreased the serum level of corticosterone in diabetic adult rats. Thus, the EE has helped to ameliorate cognitive comorbidities associated with T1DM, possibly by reducing the hyperactivity of HPA axis and the microglial activation in diabetic animals.
259

Perfil químico dos óleos essenciais de citrus aurantium lineu e citrus sinensis (L.) Osbeck e avaliação psicofarmacológica da ação ansiolítica

Wolffenbuttel, Adriana Nunes January 2014 (has links)
Este estudo pesquisou a composição química dos óleos essenciais (OE) do pericarpo (casca dos frutos) e folhas de Citrus aurantium Lineu (laranja amarga) e Citrus sinensis (L.) Osbeck (laranja doce) visando correlacionar seus constituintes com a avaliação psicofarmacológica da ação ansiolítica, através da inalação durante 30 minutos destes OE por camundongos. Os OE foram obtidos por destilação de arraste de vapor, hidrodestilação e prensagem a frio de cítricos coletados nas regiões sul e centro-sul do Brasil, tanto de extrações em laboratório como de marcas comerciais, onde constatamos a semelhança química entre seus constituintes, com importância comercial e farmacológica. Os OE provenientes do pericarpo possuem o limoneno como componente majoritário (67,7-82,5%) e os OE provenientes das folhas possuem o acetato de linalila (28,0-51,8%) e o linalol (14,2-24,8%) como componentes majoritários. O isomero (R)-(+)-limoneno é ee em todos os OE analisados. O isomero (R)-(-)-linalol é ee nos OE C. aurantium, e que o (S)-(+)-linalol é ee nos OE C. sinesis. Após a inalação, os camundongos foram submetidos a ensaios comportamentais. O OE de C. sinensis demonstrou provocar comportamento indicativo de redução da ansiedade através do teste claro-escuro e diminuição da sua atividade locomotora no teste de atividade locomotora, indicando um efeito depressor do SNC. Demonstramos que os OE inalados foram absorvidos pelo organismo dos camundongos através da detectação dos componentes dos OE, dentre eles o limoneno e o linalol no plasma dos camundongos. Quantificamos os hormônios relacionados com os estados emocionais de ansiedade e estresse, Melatonina (MEL) e Corticosterona (CORT), onde constatamos que os OE inalados não atuam no sistema que envolve a síntese da MEL, bem como no eixo hipotálamo-hipófise-adrenal da CORT. Comprovamos que o protocolo aplicado aos camundongos e o ensaio de suspensão pela cauda não são eventos estressantes, pois o hormônio CORT manteve-se nos valores basais. / This study investigated the chemical composition of essential oils (EO) of the pericarp of the fruit and leaves of Citrus aurantium Linneu (bitter orange) and Citrus sinensis (L.) Osbeck (sweet orange) in order to correlate their constituents with psychopharmacological evaluation the anxiolytic action through inhalation for 30 minutes these EO for mice. EO were obtained by steam distillation, hydrodistillation and cold pressing of Citrus collected in southern and south-central regions of Brazil, both in laboratory extractions as trademarks, which found the chemical similarity among their constituents, with important commercial and pharmacology. OE from pericarp have limonene as a major component (67.7 to 82.5%) and EO from the leaves have linalyl acetate (28.0 to 51.8%) and linalool (14.2 to 24.8%) as major components. The (R)-(+)-Limonene is ee in all OE analyzed. The (R)-(-)-linalool is ee in the OE C. aurantium, and (S)-(+)-linalool is ee in the OE C. sinensis. After inhalation, the mice were subjected to behavioral testing. The EO of C. sinensis showed cause behavior indicative of anxiety reduction through the light-dark test and decreased their locomotor activity in the locomotor activity test, indicating a CNS depressant effect. We have demonstrated that inhaled EO were absorbed by the body of the mice over the detections components of EO, including limonene and linalool, in the plasma of mice. We quantify the hormones related to emotional states of anxiety and stress, melatonin (MEL) and corticosterone (CORT), which found that inhaled OE do not work in the system involving the synthesis of MEL, as well as in the hypothalamic-pituitary-adrenal axis of CORT. We prove that the protocol applied to mice and the tail suspension test are not stressful events because the hormone CORT remained at basal values.
260

Mecanismos subjacentes ao efeito da manipulação neonatal sobre o vínculo mãe/filhote

Reis, Adolfo Rodrigues January 2014 (has links)
Ao nascerem, os mamíferos não estão com o sistema nervoso plenamente desenvolvido e os primeiros dias de vida representam uma fase crítica para o desenvolvimento desse sistema. De fato, nesta fase o encéfalo está passando por diversos processos fundamentais como organização funcional das redes neurais, proliferação neuronal, migração, diferenciação, além de gliogênese e mielinização. Em ratos, um procedimento simples, como “manipular” os filhotes por alguns minutos durante a primeira semana de vida, pode marcar decisivamente o desenvolvimento do indivíduo. Assim, a manipulação neonatal tem sido muito utilizada para se examinar os mecanismos pelos quais variações ambientais podem afetar o desenvolvimento do filhote. A manipulação neonatal promove uma série de alterações comportamentais e neuroendócrinas que se caracterizam basicamente por uma diminuição do medo e da resposta ao estresse no adulto. Embora muitos autores até caracterizem a manipulação como uma intervenção positiva ela também pode provocar graves déficits em comportamentos sociais e reprodutivos para a prole aparecendo desde o inicio do desenvolvimento e persistindo até a vida adulta. Além de seu efeito sobre os filhotes, estudos tem demostrado que intervenções na prole no período neonatal também afetam de forma duradoura a resposta ao estresse das genitoras, mas este tema ainda é muito pouco explorado pela literatura Portanto, na primeira parte desta tese, iremos estudar os efeitos da manipulação neonatal sobre a formação do vínculo mãe-filhote, tentando associar mudanças no comportamento da mãe ao longo dos 10 primeiros dias pós-parto com a preferencia pelo odor do ninho em filhotes testados no labirinto em Y. Na segunda parte desta tese iremos abordar os efeitos da manipulação sobre a resposta ao estresse agudo e crônico em ratas que tiveram seus filhotes manipulados no período neonatal, para isso submetemos genitoras dos grupos controle e manipulado após o desmame a um dos dois protocolos descritos a seguir: com estresse (estresse por contenção de movimentos 1h/dia por 7 dias) ou sem estresse (nenhuma intervenção após o desmame) e testamos os animais através do teste de nado forçado para observar mudanças na resposta emocional. Também medimos os níveis de BDNF e corticosterona no plasma após o teste e medimos o peso das adrenais para verificar o efeito da manipulação na resposta ao estresse das genitoras Os resultados dessa tese mostram que a manipulação neonatal afeta a estrutura do comportamento maternal, mudando a sequencia e a sincronia do comportamento da mãe com o filhote, o que poderia ser em parte a causa da alteração no comportamento de preferencia pelo odor do ninho observado em animais manipulados, principalmente nas fêmeas. Além disso, observamos que a manipulação afeta de forma duradoura a resposta ao estresse (agudo e crônico) das genitoras, podendo alterar a resposta emocional desses animais e predispor a sintomas do tipo depressivo em resposta ao estresse agudo Esses resultados reforçam a ideia de que o estudo dos efeitos duradouros da manipulação não só nos filhotes, mas também no organismo materno, podem servir como uma importante ferramenta para elaboração de projetos clínicos, visando a exploração da existência de comportamentos similares em humanos. Isso ajudará na elaboração de politicas de saúde publica que visem minimizar os efeitos de eventos adversos acontecidos no inicio da vida sobre a saúde física e mental tanto da mãe quanto da criança. / Mammals are not born with fully developed nervous system, and the first days of life represent a critical stage in the development of this system. In fact, at this stage, the brain is undergoing many fundamental processes such as functional organization of neural networks, neuronal proliferation, migration, differentiation, gliogenesis and myelination. In rats, a simple procedure such as "handling" the pups for a few minutes during the first week of life can decisively mark the development of the individual. Thus, neonatal handling has been widely used to examine the mechanisms by which environmental adversity can affect the development of the pups. Neonatal handling promotes a series of behavioral and neuroendocrine changes that are characterized primarily by a decrease of fear and stress responses in the adult. Although many authors characterize the handling procedure as a positive intervention, it is also associated with severe deficits in social and reproductive behaviors of the offspring that appear early during development and persist into adulthood. Apart from its effect on the pups, studies have shown that interventions in the offspring during the neonatal period can also induce long lasting effects in the maternal stress response, but this subject is still little explored in the literature Therefore, in the first part of this thesis, we will study the effects of neonatal handling on the mother-pups’ bond formation, trying to associate changes in maternal behavior over the first 10 days postpartum with the preference for the odor of the nest in pups tested the Y maze. The second part of this thesis will address the effects of neonatal handling on the acute and chronic stress response in dams that had their pups handled. For this purpose, we submitted mothers of control and manipulated groups after weaning to: stress (restraint 1h/day for 7 days) or no stress (no intervention after weaning) and tested the animals using the forced swim test to observe changes in emotional response. We also measured plasma BDNF and corticosterone levels after the test and the adrenals’ weight to verify the effect of handling on the dam’s stress response. The results of this thesis show that neonatal handling affects the structure of maternal behavior, changing the behavioral sequence and synchrony of the mother with her pups, which could be in part the cause of the altered social behaviors observed in handled pups, especially in females. Moreover, we observed that handling affects the dam´s response to stress (acute and chronic), and may alter the emotional response of the dams increasing the susceptibility to developing psychiatric disorders such as depression at least in response to acute stress These results reinforce the idea that investigating the long lasting effects of handling not only in the young, but also in the dam’s physiology becomes an important tool for the development of clinical studies, aiming at exploring the existence of similar effects in humans. The final goal will be the elaboration of public health policy to minimize the effects of early life adverse events on physical and mental health of both mothers and their children.

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