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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.
861

Efeitos do treinamento físico por natação sobre o sistema cardiovascular e marcadores moleculares de hipertrofia cardíaca em ratas wistar / Swimming training effects on cardiovascular system and hypertrofic cardiac molecular markesrs in wistar females

Hashimoto, Nara Yumi 20 September 2007 (has links)
O treinamento por natação leva a uma sobrecarga de volume no coração, que induz a hipertrofia cardíaca (HC) excêntrica, com aumento da massa e do diâmetro cardíaco. Neste trabalho foram investigadas as adaptações no sistema cardiovascular e na expressão de genes relacionados à HC patológica, na gênese da HC por treinamento de natação. 42 ratas wistar foram divididas em grupos: sedentário controle (SC) treinado protocolo 1 (P1) e treinado protocolo 2 (P2). O treinamento de P1 foi de 1x60min/dia, 5x/semana, por 10 semanas. O de P2 foi igual ao P1 até a 8ª semana. Na 9ª semana 2x/dia e na 10ª semana 3x/dia. Os grupos treinados, em relação ao SC, apresentaram bradicardia de repouso, melhora no desempenho físico do teste máximo e do consumo máximo de oxigênio e HC, sem alterar a pressão arterial média e a expressão dos genes do fator natriurético atrial e da alfa actina esquelética. O grupo P2 apresentou aumento no diâmetro cardíaco e redução da expressão do gene da beta miosina de cadeia pesada. Este último resultado é contrário à literatura para a HC patológica, que mostra o aumento não só da expressão deste gene como a dos outros genes estudados. Os resultados de HC de P2 assemelham-se aos encontrados em estudos recentes com atletas de modalidades de maior componente aeróbio, sendo este um bom modelo para investigação dos mecanismos envolvidos na HC destes atleta / Swimming training leads to a cardiac volume overload that induces excentric cardiac hypertrophy (CH) with an increase in cardiac mass and diameter. Cardiovascular system adaptations and expression of genes relatated with pathological CH were investigated in swimming training CH. We studied 42 wistar females, divided in sedentary control (SC) group, protocol 1 trained group (P1) and protocol 2 trained group (P2). The P1 training program was once a day for 5 times/week for 10 weeks. P2 was the same as P1 until 8th week. In 9th week it was twice a day and in 10th week 3 times a day. Trained groups, in contrast with SC, showed rest bradycardia, improvement in physical performance, maximum oxygen uptake and CH, with no alteration in the medium arterial pressure and in the expression of atrial natriuretic factor and skeletal alpha actin genes. Moreover, P2 showed an increase in cardiac diameter and decrease in the expression of beta myosin heavy chain gene. This expression result is different of patological CH literature wich shows an increase of this gene expression and also in the others genes we had investigated. P2 CH results were similar to those recently found in endurance-type athletes, sugesting this is a good model to investigate mechanisms involved in endurance-type athletes CH
862

Etude des effets de la pratique de l'apnée pendant l'effort en laboratoire et sur le terrain : application en natation / Study of the effects of the practice of the apnea during exercise in laboratory and in the field : application in swimming

Guimard, Alexandre 12 December 2017 (has links)
Existant en tant que pratique sportive, l’apnée est également de plus en plus utilisée dans d’autres activités sportives dont la natation, à l’entraînement et/ou en compétition. Toutefois, les réponses à l‘apnée dynamique ont été peu explorées lors d’efforts physiques intenses, en particulier en natation. L’objectif de ce travail de thèse est donc d’étudier sur le terrain en situation de nage (étude 1 et 2) et en laboratoire (étude 3) lors d’un exercice intermittent de pédalage, les réponses physiologiques, psychologiques et ergogéniques à l’apnée aiguë apparaissant lors d’efforts intenses. Le métabolisme a été notamment évalué à partir de la mesure de l’oxygénation tissulaire, de paramètres sanguins et de marqueurs hormonaux. Les principaux résultats de ces études montrent qu’en apnée la performance dépendrait de la capacité des sujets à maintenir leur fréquence cardiaque et que l’effort est globalement perçu comme plus dur. L’apnée n’induisait pas d’augmentation de la lactatémie, sans doute en lien avec l’absence de modification de l’extraction musculaire de l’oxygène. Au niveau cérébral, le maintien de l’oxygénation expliquerait la non modification du temps de réaction en apnée. Enfin toutes nos études ont révélé une désaturation artérielle significative en apnée, dès la première apnée de 10 secondes (étude 3) mais sans effet de la capacité d’apnée (étude 1) ou de l’intensité de nage (étude 2) suggérant que la durée compenserait l’intensité. Il serait donc intéressant d’étudier ultérieurement les effets respectifs du couple intensité/durée et les effets chroniques d’un entraînement comportant un exercice intermittent intense lors d’apnées dynamiques. / Existing as a sport practice, apnea is also increasingly used in other sports activities including swimming, training and/or competition. However, responses to dynamic apnea have been little explored during intense physical exercise, especially in swimming. The objective of this thesis is to study, in the field in swimming situations (study 1 and 2) and in the laboratory (study 3) during an intermittent cycling exercise, the physiological, psychological and ergogenic responses to acute apnea appearing during intense exercises. Metabolism was especially assessed by measurement of tissue oxygenation, blood parameters and hormonal markers. The main results of these studies show that in apnea the performance would depend on the ability of the subjects to maintain their heart rate and that the exercise is globally perceived as harder. Apnea did not induce an increase in lactatemia, probably related to the lack of modification of the muscle extraction of oxygen. At the cerebral level, the maintenance of the oxygenation would explain that the reaction time is not altered with apnea. Finally, all our studies revealed a significant arterial desaturation in apnea at the first repetition of the 10-second apnea (study 3) but without the effect of apnea capacity (study 1) or swimming intensity (study 2) suggesting that the duration would compensate for the intensity. It would therefore be interesting to study later the respective effects of the intensity/duration pair and the chronic effects of training involving intense intermittent exercise during dynamic apneas.
863

Entrenament de la propiocepció conscient de la CV lumbar: Una aplicació a la natació subaquàtica

Solana Tramunt, Mònica 15 September 2011 (has links)
Aquesta tesi és una aproximació teòrica i empírica a la metodologia actualitzada per a l'entrenament de la propiocepció. La part teòrica desenvolupa l'estat de la qüestió en l'estudi de la propiocepció des de diferents perspectives, de les particularitats de la columna vertebral lumbar i de les característiques de la propiocepció en aquesta zona del raquis. Ens resumeix els aspectes més importants de la teoria de l'entrenament i les necessitats de l'entrenament propioceptiu lumbar en la natació competitiva. La part empírica pretén ser un punt de partida en la investigació experimental de la metodologia més adequada per a l'entrenament de la propiocepció conscient. Es realitza un disseny específic per a la millora del control de la CV lumbar en la tècnica de natació subaquàtica, en el qual es tracta d'intercedir sobre l'amplitud de moviment lumbar en el pla sagital i sobre la precisió en el seu posicionament dins del mateix pla. S'aplica, s'avalua i es comparen els efectes de l'administració d’uns exercicis durant 75 sessions, en un període de 2-3 mesos naturals, amb dues metodologies d'execució diferenciades: Amb ulls tapats centrant l'atenció sobre la zona lumbar i sense cap condició diferent a la de complir la tècnica d'execució del moviment. Els resultats de l'estudi experimental demostren que el mètode que millora les variables relacionades amb la propiocepció és el que proposa la realització dels exercicis amb els ulls tancats i centrant l'atenció sobre la zona lumbar, mentre que amb els ulls oberts empitjoren aquestes variables respecte al grup control. Ambdós mètodes provoquen millores significatives de l'amplitud de moviment lumbar en el pla treballat. En línies generals tot el procés revela la necessitat d'actualitzar el tractament conceptual i metodològic de la propiocepció, posant un exemple d'intervenció en la natació competitiva que orienta sobre les bases per a la seva aplicació en altres esports. / Esta tesis es una aproximación teórica y empírica a la metodología actualizada para el entrenamiento de la propiocepción. La parte teórica desarrolla el estado de la cuestión en el estudio de la propiocepción desde diferentes perspectivas, de las particularidades de la columna vertebral lumbar y de las características de la propiocepción en ésta zona del raquis. Nos resume los aspectos más importantes de la teoría del entrenamiento y las necesidades del entrenamiento propioceptivo lumbar en la natación competitiva. La parte empírica pretende ser un punto de partida en la investigación experimental de la metodología más adecuada para el entrenamiento de la propiocepción consciente. Se realiza un diseño específico para la mejora del control de la CV lumbar en la técnica de natación subacuática, en el que se trata de interceder sobre la amplitud de movimiento lumbar en el plano sagital y sobre la precisión en su posicionamiento dentro del mismo plano. Se aplica, se evalúa y se comparan los efectos de la administración de unos ejercicios durante 75 sesiones, en un período de 2-3 meses naturales, con dos metodologías de ejecución diferenciadas: Con ojos cerrados centrando la atención sobre la zona lumbar y con los ojos abiertos sin ninguna condición diferente a la de cumplir la técnica de ejecución del movimiento. Los resultados del estudio experimental demuestran que el método que mejora las variables relacionadas con la propiocepción es el que propone la realización de los ejercicios con los ojos cerrados, mientras que con los ojos abiertos empeoran estas variables con respecto al grupo control. Ambos métodos provocan mejoras significativas de la amplitud de movimiento lumbar en el plano trabajado. Todo el proceso revela la necesidad de actualizar el tratamiento conceptual y metodológico de la propiocepción a partir de una intervención en la natación, y orienta sobre las bases para su aplicación en otros deportes. / This thesis is a theoretical and empirical approach to the updated methodology for proprioception training. The theoretical part develops the state of affairs in the study of proprioception from different perspectives, the particulars of the lumbar spine and the characteristics of proprioception in this area of the spine. It’s summarized the most important aspects of training theory and the needs of lumbar proprioceptive training in competitive swimming. The empirical part is intended as a starting point for experimental research on the most appropriate methodology for the conscious proprioception training. It performs a specific design for improved lumbar spine control on underwater swimming technique, which tries to intercede on lumbar range of motion in the sagittal plane and positioning accuracy within the same plane. It applies, evaluates and compares the effects of exercises’ administration during 75 sessions over 2 to 3 calendar months, with two different methods of execution: First one blindfolded and focusing on the lower back and second one with eyes opened and no different condition to fulfill the technical execution. The results show that the method improves proprioception-related variables is proposed conducting the exercises with eyes closed focusing on the lower back, while with eyes opened this variables get worse towards the control group. Both methods lead to significant improvements in lumbar range of motion in the worked plane. Thus, the process reveals the need to update the conceptual and methodological treatment of proprioception after an intervention in swimming, and guides about the basis for its application in other sports.
864

Vulnerable London: narratives of space and affect in a twentieth-century imperial capital / Narratives of space and affect in a twentieth-century imperial capital

Avery, Lisa Katherine, 1968- 28 August 2008 (has links)
This dissertation examines sensation in twentieth-century narratives of London and argues that vulnerability is a constitutive experience of the post-imperial city. Sensations of vulnerability in London arise because of the built environment of the city: its status as an imperial center and a global capital create important intersections of local, national, and global concerns which render the city itself vulnerable. I chart the trajectory of vulnerability as an affective history of London that is documented in cultural texts ranging from fiction and film to political debates and legal materials. Since the sensational experiences of the present partly arise from the materials of the past embedded in the landscape, affective histories create new ways of understanding history as a spatial experience. The narrated sensations of the city make vulnerability legible as a persistent feature of twentieth-century London life. I begin with a modernist, imperial London, in Virginia Woolf's Mrs. Dalloway and in Parliamentary debates from the same year (1925). Ambivalence about London's dual status as a local site and as a national and international capital is a response to London's vulnerable position at the end of the Great War. Next, I turn to World War Two London and Elizabeth Bowen's The Heat of the Day. I discuss intimacy as an important national feature in narratives of London during the crisis of this war. National narratives about intimacy constructed by Winston Churchill and heard on BBC radio respond directly to London's defensive vulnerability. My third chapter concerns Margaret Thatcher's 1980s London and the crucial role autonomy plays in constructing London as an invulnerable, international financial and civic capital. Alan Hollinghurst's The Swimming-Pool Library documents Londoners' attempts to make sense of their autonomy in a postimperial capital. My final chapter examines sensations of social and political belonging in contemporary London through reading Stephen Frears's Dirty Pretty Things alongside legal documents about immigration. I contend that reading cultural texts affectively creates counter-histories of the city that accommodate a deeper range of experiences than do traditional histories and offers to literary studies a new way of understanding the relationship between official and unofficial histories. / text
865

Die Belastung und Belastbarkeit von Schwimmtauchern unter besonderer Berücksichtigung der Konfiguration der Ausrüstung sowie des passiven und dynamischen Widerstands - dargestellt anhand von objektivierenden Untersuchungsmethoden / Energetics and endurance of swimming divers, with special consideration of the equipment configuration and of the active and passive drag established by objectifiable test methods

Droste, Thomas 13 January 2005 (has links)
No description available.
866

Simulation of individual cells in flow

Zhu, Lailai January 2014 (has links)
In this thesis, simulations are performed to study the motion ofindividual cells in flow, focusing on the hydrodynamics of actively swimming cells likethe self-propelling microorganisms, and of passively advected objects like the red bloodcells. In particular, we develop numerical tools to address the locomotion ofmicroswimmers in viscoelastic fluids and complex geometries, as well as the motion ofdeformable capsules in micro-fluidic flows. For the active movement, the squirmer is used as our model microswimmer. The finiteelement method is employed to study the influence of the viscoelasticity of fluid on theperformance of locomotion. A boundary element method is implemented to study swimmingcells inside a tube. For the passive counterpart, the deformable capsule is chosen as the modelcell. An accelerated boundary integral method code is developed to solve thefluid-structure interaction, and a global spectral method is incorporated to handle theevolving cell surface and its corresponding membrane dynamics. We study the locomotion of a neutral squirmer with anemphasis on the change of swimming kinematics, energetics, and flowdisturbance from Newtonian to viscoelastic fluid. We also examine the dynamics of differentswimming gaits resulting in different patterns of polymer deformation, as well as theirinfluence on the swimming performance. We correlate the change of swimming speed withthe extensional viscosity and that of power consumption with the phase delay of viscoelasticfluids. Moreover, we utilise the boundary element method to simulate the swimming cells in astraight and torus-like bent tube, where the tube radius is a few times the cell radius. Weinvestigate the effect of tube confinement to the swimming speed and power consumption. Weanalyse the motions of squirmers with different gaits, which significantly affect thestability of the motion. Helical trajectories are produced for a neutralsquirmer swimming, in qualitative agreement with experimental observations, which can beexplained by hydrodynamic interactions alone. We perform simulations of a deformable capsule in micro-fluidic flows. We look atthe trajectory and deformation of a capsule through a channel/duct with a corner. Thevelocity of capsule displays an overshoot as passing around the corner, indicating apparentviscoelasticity induced by the interaction between the deformable membrane and viscousflow. A curved corner is found to deform the capsule less than the straight one. In addition, we propose a new cell sorting device based on the deformability of cells. Weintroduce carefully-designed geometric features into the flow to excite thehydrodynamic interactions between the cell and device. This interaction varies andclosely depends on the cell deformability, the resultant difference scatters the cellsonto different trajectories. Our high-fidelity computations show that the new strategy achievesa clear and robust separation of cells. We finally investigate the motion of capsule in awall-bounded oscillating shear flow, to understand the effect of physiological pulsation to thedeformation and lateral migration of cells. We observe the lateral migration velocity of a cellvaries non-monotonically with its deformability. / <p>QC 20140313</p>
867

Effects of Hypoxia and Exercise on In Vivo Lactate Kinetics and Expression of Monocarboxylate Transporters in Rainbow Trout

Omlin, Teye D. 21 February 2014 (has links)
The current understanding of lactate metabolism in fish is based almost entirely on interpretation of concentration measurements that cannot be used to infer changes in flux. Moreover, the transporters regulating these fluxes have never been characterized in rainbow trout. My goals were: (1) to quantify lactate fluxes in rainbow trout under normoxic resting conditions, during acute hypoxia, and exercise by continuous infusion of [U-14C] lactate; (2) to determine lactate uptake capacity of trout tissues by infusing exogenous lactate in fish rest and during graded exercise, and (3) to clone monocarboxylate transporters (MCTs) and determine the effects of exhausting exercise on their expression. Such information could prove important to understand the mechanisms underlying the classic “lactate retention” seen in trout white muscle after intense exercise. In normoxic resting fish, the rates of appearance (Ra) and disappearance (Rd) of lactate were always matched (~18 to 13 µmol kg-1 min-1), thereby maintaining a low baseline blood lactate concentration (~0.8 mM). In hypoxic fish, Ra lactate increased from baseline to 36.5 µmol kg-1 min-1, and was accompanied by an unexpected 52% increase in Rd reaching 30.3 µmol kg-1 min-1, accounting for a rise in blood lactate to 8.9 mM. In exercising fish, lactate flux was stimulated > 2.4 body lengths per second (BL s-1). As the fish reached critical swimming speed (Ucrit), Ra lactate was more stimulated (+67% to 40.4 μmol kg-1 min-1) than Rd (+41% to 34.7 μmol kg-1 min-1), causing an increase in blood lactate to 5.1mM. Fish infused with exogenous lactate stimulated Rd lactate by 300% (14 to 56 μmol kg-1 min-1) during graded exercise, whereas the Rd in resting fish increased by only 90% (21 to 40 µmol kg-1 min-1). Four MCT isoforms were partially cloned and characterized in rainbow trout: MCT1b was the most abundant in heart, and red muscle, but poorly expressed in gill and brain where MCT1a and MCT2 were prevalent. MCT4 was more expressed in the heart. Transcript levels of MCT2 (+260%; brain), MCT1a (+90%; heart) and MCT1b (+50%; heart) were stimulated by exhausting exercise. This study shows that: (i) the increase in Rd lactate plays a strategic role in reducing the lactate load imposed on the circulation. Without this response, blood lactate accumulation would double; (ii) a high capacity for lactate disposal in rainbow trout tissues is elicited by the increased blood-to-tissue lactate gradient when extra lactate is administered; and (iii) rainbow trout may be unable to release large lactate loads rapidly from white muscle after exhausting exercise (lactate retention) because they poorly express MCT4 in white muscle and fail to upregulate its expression during exercise.
868

Efeitos a longo prazo de diferentes separações dos filhotes no período neonatal sobre as genitoras

Toigo, Eduardo von Poser January 2011 (has links)
Esse estudo foi realizado para verificar se a exposição a separações repetidas (por diferentes intervalos de tempo) de mães dos seus filhotes no período neonatal poderiam ser classificadas como indutoras de um estado do tipo deprimido em genitoras. Sessenta ratas Wistar prenhes foram divididas em 3 grupos: controle, separação por 10 minutos e separação por 3 horas. As intervenções neonatais foram realizadas nos dias 1-10 pós parto. Após o desmame as genitoras foram submetidas ao teste do nado forçado, ao teste do labirinto em cruz elevado e ao teste do odor de predador. Também foi avaliado o comportamento alimentar e os padrões de reatividade a um sabor doce e a um sabor amargo. Foi medido os níveis de ocitocina no líquido cefaloraquidiano, corticosterona plasmática e atividade hipocampal Na+, K+-ATPase, assim como a atividade das enzimas antioxidantes catalase, glutationa peroxidase, superoxido dismutase, produção de radicais livres, e a produção de óxido nítrico, além dos níveis dos receptores A2A de adenosina e D2 de dopamina no estriado dorsoventral e no hipocampo. Foi observado que somente a separação por 3 h induziu um aumento significativo no tempo de imobilidade no teste do nado forçado, o que é consistente com estudos prévios. A atividade hipocampal da Na+, K+-ATPase se mostrou diminuída no grupo separado por 10 minutos e mais significativamente diminuída nas genitoras submetidas a separação por 3 horas de seus filhotes. Adicionalmente, os níveis de ocitocina no líquido cefaloraquidiano se encontravam aumentados no grupo separado por 10 minutos, o que pode estar relacionado a um aumento no cuidado materno, induzido por esta manipulação dos filhotes, por parte das genitoras, como reportado na literatura. Uma redução nos níveis de óxido nítrico no hipocampo das genitoras separadas por 3 horas foi observado Nessas genitoras também foi verificado um aumento no comportamento de risco, uma diminuição no sentimento prazeroso frente a uma solução doce e aumento na sensibilidade a uma solução aversiva, o que é congruente a um perfil de estado do tipo deprimido. Além disso, nós verificamos uma diminuição na quantidade do receptor de dopamina D2 no estriado das mães submetidas a separação por 3 horas dos filhotes, o que poderia ser relacionado com uma diminuição no prazer (anedonia) que acontece na depressão. Conclui-se que a retirada dos filhotes das mães por longos períodos tornam essas mães mais susceptíveis ao desenvolvimento de características depressivas. / This study was carried out to ascertain whether exposure to repeated separations (different times) of mothers from their pups in the neonatal period could be classified as an induction of a depressive-like state in dams. Sixty Wistar rats were divided into 3 groups: control, brief separation and long-term separation. The neonatal interventions were done on postpartum days 1-10. After weaning, the dams were subjected to the forced swimming test, elevated plus maze and predator odor test. It was also evaluated the feeding behavior and the taste reactivity patterns to a sweet and to a bitter solution. It was mesaured cerebral spinal fluid oxytocin, plasma corticosterone, and hippocampal Na+, K+-ATPase activity, as well as the activity of the antioxidant enzymes catalase, glutathione peroxidase, superoxide dismutase, free radicals production, and the production of nitric oxide and the levels of adenosine A2A and dopamine D2 receptors in the dorsoventral striatum and hippocampus. It was observed that only the 3 h separation induced a significant increase in the immobility time of rats in the forced swimming test, which is consistent with previous studies. Hippocampal Na+, K+-ATPase activity was decreased in the brief separated group and more significantly decreased in dams subjected to 3h separation from their pups. Additionally, cerebral spinal fluid oxytocin was increased in dams of the brief separated group, which may be related to the increased handled-induced maternal care, as reported in the literature. A reduction in nitric oxide levels in the hippocampus in dams of the long separated group was also observed. It was also verify an increase in the risk-taking behavior by the 3h separated mothers. The 3h separated mother also demonstrated a diminished feeling of pleasure with a sucrose solution and a increased sensibility to a aversive solution, wich is congruent with a depressive like state profile. Furthermore, we shown a decrease in the dopamine D2 receptor quantity in the striatum of the 3 h separated mothers, wich could be related to a decrease in pleasure feeling (anhedonia) experienced in depression. It is concluded that the withdrawal of pups from their mothers for long periods make the mothers more susceptible to the development of depressive features.
869

Matematika ve sportu / Mathematics and Sport

PALÁTOVÁ, Petra January 2013 (has links)
The thesis elaborates on relations between PE or sports in general, and mathematics. The author focuses on a practical application of numbers on sports such football, swimming, track and field, downhill skiing and Olympic games. Moreover, the mentioned numerical methods are further used for writing a workbook of model exercises for grammar schools. The thesis is divided into two main chapters ? theoretical and practical. The theoretical part consists of selected sports which are expressed and described by numbers and formulas. In the practical part, a reader can find the workbook of model exercises which has been completed using all the mathematical sources discussed in the theoretical part. There are also correct solutions exercises available for self-studying students.
870

Efeitos a longo prazo de diferentes separações dos filhotes no período neonatal sobre as genitoras

Toigo, Eduardo von Poser January 2011 (has links)
Esse estudo foi realizado para verificar se a exposição a separações repetidas (por diferentes intervalos de tempo) de mães dos seus filhotes no período neonatal poderiam ser classificadas como indutoras de um estado do tipo deprimido em genitoras. Sessenta ratas Wistar prenhes foram divididas em 3 grupos: controle, separação por 10 minutos e separação por 3 horas. As intervenções neonatais foram realizadas nos dias 1-10 pós parto. Após o desmame as genitoras foram submetidas ao teste do nado forçado, ao teste do labirinto em cruz elevado e ao teste do odor de predador. Também foi avaliado o comportamento alimentar e os padrões de reatividade a um sabor doce e a um sabor amargo. Foi medido os níveis de ocitocina no líquido cefaloraquidiano, corticosterona plasmática e atividade hipocampal Na+, K+-ATPase, assim como a atividade das enzimas antioxidantes catalase, glutationa peroxidase, superoxido dismutase, produção de radicais livres, e a produção de óxido nítrico, além dos níveis dos receptores A2A de adenosina e D2 de dopamina no estriado dorsoventral e no hipocampo. Foi observado que somente a separação por 3 h induziu um aumento significativo no tempo de imobilidade no teste do nado forçado, o que é consistente com estudos prévios. A atividade hipocampal da Na+, K+-ATPase se mostrou diminuída no grupo separado por 10 minutos e mais significativamente diminuída nas genitoras submetidas a separação por 3 horas de seus filhotes. Adicionalmente, os níveis de ocitocina no líquido cefaloraquidiano se encontravam aumentados no grupo separado por 10 minutos, o que pode estar relacionado a um aumento no cuidado materno, induzido por esta manipulação dos filhotes, por parte das genitoras, como reportado na literatura. Uma redução nos níveis de óxido nítrico no hipocampo das genitoras separadas por 3 horas foi observado Nessas genitoras também foi verificado um aumento no comportamento de risco, uma diminuição no sentimento prazeroso frente a uma solução doce e aumento na sensibilidade a uma solução aversiva, o que é congruente a um perfil de estado do tipo deprimido. Além disso, nós verificamos uma diminuição na quantidade do receptor de dopamina D2 no estriado das mães submetidas a separação por 3 horas dos filhotes, o que poderia ser relacionado com uma diminuição no prazer (anedonia) que acontece na depressão. Conclui-se que a retirada dos filhotes das mães por longos períodos tornam essas mães mais susceptíveis ao desenvolvimento de características depressivas. / This study was carried out to ascertain whether exposure to repeated separations (different times) of mothers from their pups in the neonatal period could be classified as an induction of a depressive-like state in dams. Sixty Wistar rats were divided into 3 groups: control, brief separation and long-term separation. The neonatal interventions were done on postpartum days 1-10. After weaning, the dams were subjected to the forced swimming test, elevated plus maze and predator odor test. It was also evaluated the feeding behavior and the taste reactivity patterns to a sweet and to a bitter solution. It was mesaured cerebral spinal fluid oxytocin, plasma corticosterone, and hippocampal Na+, K+-ATPase activity, as well as the activity of the antioxidant enzymes catalase, glutathione peroxidase, superoxide dismutase, free radicals production, and the production of nitric oxide and the levels of adenosine A2A and dopamine D2 receptors in the dorsoventral striatum and hippocampus. It was observed that only the 3 h separation induced a significant increase in the immobility time of rats in the forced swimming test, which is consistent with previous studies. Hippocampal Na+, K+-ATPase activity was decreased in the brief separated group and more significantly decreased in dams subjected to 3h separation from their pups. Additionally, cerebral spinal fluid oxytocin was increased in dams of the brief separated group, which may be related to the increased handled-induced maternal care, as reported in the literature. A reduction in nitric oxide levels in the hippocampus in dams of the long separated group was also observed. It was also verify an increase in the risk-taking behavior by the 3h separated mothers. The 3h separated mother also demonstrated a diminished feeling of pleasure with a sucrose solution and a increased sensibility to a aversive solution, wich is congruent with a depressive like state profile. Furthermore, we shown a decrease in the dopamine D2 receptor quantity in the striatum of the 3 h separated mothers, wich could be related to a decrease in pleasure feeling (anhedonia) experienced in depression. It is concluded that the withdrawal of pups from their mothers for long periods make the mothers more susceptible to the development of depressive features.

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