Estrutura central do hipocampo, o corno de Ammon pode ser subdividido em pelo menos três áreas: CA1, CA2 e CA3. Enquanto CA1 e CA3 foram extensamente estudados, dado o envolvimento do hipocampo em processos cognitivos como a memória e patológicos como a epilepsia, CA2 tem sido largamente ignorado na literatura. Entretanto, este campo possui características específicas, tanto neuroanatômicas como bioquímicas e fisiológicas, sendo resistente à indução de plasticidade e recebendo aferência específica do núcleo supramamilar do hipotálamo, envolvido na circuitaria geradora/mantenedora do ritmo teta, oscilações centrais ao funcionamento do hipocampo. O objetivo deste estudo foi, portanto, caracterizar no animal em livre movimentação os padrões de atividade eletrofisiológica nas três áreas do corno de Ammon bilateralmente. Os resultados demonstraram que CA2 possui, em média, intervalos entre disparos mais prolongados que CA1 e CA3 durante o sono de ondas lentas e o sono REM. Nestas fases do ciclo a coerência entre CA1-CA2 foi mais elevada que entre CA1-CA3 e CA2-CA3 nos três ratos avaliados, em três faixas de freqüência: teta (6 a 12 Hz), gama lento (30 a 50 Hz) e gama rápido (90 a 110 Hz) ipsilateralmente. A coerência entre campos contralaterais é predominante no teta, sendo quase zero nas demais freqüências. Estes resultados corroboram trabalhos recentes que apontam CA2 como área distinta e sugerem que esta pequena região do corno de Ammon possa exercer papéis importantes na modulação da atividade das demais estruturas hipocampais e parahipocampais em processos de memória e em patologias como a epilepsia / The Ammons horn, central structure of the hippocampus, can be subdivided in at least three regions: CA1, CA2 and CA3. While CA1 and CA3 have been extensively studied given the hippocampus involvement in cognitive processes such as memory and pathological ones such as epilepsy, CA2 remains largely ignored. However, this sector contains specific neuroanatomical, biochemical e physiological characteristics, being resistant to induction of plasticity and receiving a specific afference from the supramammillary nucleus in the hypothalamus, involved in the generation/maintenance of the theta rhythm, central oscillations to hippocampal functioning. Therefore, the objective of this study was to characterize electrophysiological patterns of interaction in the three areas of the Ammons horn bilaterally. Results revealed that CA2 has a mean interspike interval larger than CA1 and CA3 during slow wave and REM sleep. During these stages of the sleep-wake cycle, coherence between CA1-CA2 was higher than CA1-CA3 and CA2-CA3 in the three animals evaluated, in three frequency bands: theta (6 to 12 Hz), slow gamma (30 to 50 Hz) and fast gamma (90 to 110 Hz) ipsilaterally. Coherence between contralateral fields was predominant in the theta band and almost zero in other frequencies. These results add to some previous published data showing that CA2 is distinct from the other subfields and that this small region of the Ammons horn may exert important roles in modulating activity in the other hippocampal fields and parahippocampal regions during memory and pathologies such as epilepsy

Made available in DSpace on 2016-04-28T20:40:10Z (GMT). No. of bitstreams: 1 Marisa Vicente Catta-Preta.pdf: 1759673 bytes, checksum: 805db40ca7bdd538a0ecc796b421fd2c (MD5) Previous issue date: 2009-06-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work had as a goal to observe and analyze the dream images as a therapeutic instrument in the assistance of the treatment for patients with primary, chronic and intermediate insomnia. Group work was used in the analyses of dream reports from individuals with insomnia in fifteen meetings. The usage of remembered dreams allowed us to access to unconscious contents and from that we worked therapeutically the conflicts that were presented and that could be interfering in the insomnia. The subjects were three adults of the female sex. The choice of subjects followed the criteria of the diagnoses of chronic and intermediate insomnia, and also the criteria of availability for research, furthermore they had to remember their dreams on a regular basis. We asked the subjects to participate in an individual interview before attending the group meetings, answering questions about their sleep, dreams and also take a polysomnography so that the quality of their sleep could be analyzed. During the meetings the remembered dreams were reported and worked through with the group from the personal associations of the dreamer. Through the analyses of the dream series it was possible to present to the subjects the emotional aspects that were about an ordinary theme, which brought about a certain repetition and should be elaborated and integrated by the subject. Also, during this period, we asked the subjects to register in a diary, supplied by the researcher, the number of hours of sleep, the number of interruptions during the night, if the dream in general was good or bad and the dreams that were remembered. The method used was qualitative, and from that we analyzed the process of each subject. The data acquired was analyzed to the light of analytical psychology, following the reference of dream analyses of this approach. After the termination of the groups, the subjects took a new polysomnography in the Sleep Institute of Santos (Instituto do Sono de Santos); they did a final and individual interview with the same questions about sleep and dream. Considering the amount of hours of sleep, the quality of sleep and the individual s perception of a better quality of life as criteria for improvement, we can say that the group work with the dream images helped in the treatment of the subjects insomnia. Through the dream analyses it was possible to present the subjects the emotional aspects that were about an ordinary theme, that should be elaborated and integrated by the subject / Este trabalho teve como objetivo observar e analisar imagens oníricas como instrumento terapêutico no auxílio ao tratamento de indivíduos diagnosticados com insônia primária crônica e intermediária. Utilizou-se o trabalho em grupo para que fossem analisados sonhos de indivíduos insones durante 15 encontros. O uso de sonhos lembrados permitiu que se pudesse ter acesso a conteúdos inconscientes dos sujeitos e, a partir disso, se trabalhar terapeuticamente os conflitos apresentados que pudessem estar interferindo no quadro de insônia. Os sujeitos foram três adultos do sexo feminino. A escolha dos sujeitos seguiu o critério de terem o diagnóstico de insônia crônica e intermediária e estarem disponíveis para a pesquisa, além de lembrarem-se regularmente de seus sonhos. Foi pedido aos sujeitos que, antes de serem iniciados os encontros grupais, participassem de uma entrevista individual com a pesquisadora para responder a questões sobre seu sono e seus sonhos, e que realizassem uma polissonografia para avaliação da qualidade de seu sono. Durante os encontros, os sonhos lembrados eram relatados e trabalhados com o grupo a partir de associações pessoais do sonhador. Através da análise da série de sonhos foi possível apresentar aos sujeitos aspectos emocionais que versavam sobre um tema comum, que trazia certa repetição e deveria ser elaborado e integrado pelo sujeito. Também durante esse período pediu-se aos sujeitos que registrassem num diário, fornecido pela pesquisadora, itens que incluíam número de horas de sono, número de interrupções durante a noite, se o sono em geral fora bom ou ruim e o registro de sonhos lembrados. O método usado foi o qualitativo, a partir do qual foram feitas análises do processo de cada sujeito. Os dados obtidos foram analisados à luz da psicologia analítica, seguindo a referência de análise de sonhos dessa abordagem. Após o encerramento dos grupos, os sujeitos fizeram nova polissonografia no Instituto do Sono de Santos e uma entrevista final, individual, na qual foram reaplicadas as mesmas perguntas sobre sono e sonhos utilizadas na entrevista inicial. Considerando como critério de melhora de insônia o aumento de horas do sono, a qualidade do sono e a percepção do indivíduo de uma melhor qualidade de vida, pode-se dizer que o trabalho grupal com imagens oníricas auxiliou no tratamento da insônia dos sujeitos

Made available in DSpace on 2014-12-17T15:36:56Z (GMT). No. of bitstreams: 1 RafaelNBS.pdf: 1024882 bytes, checksum: c829a50c3f00bc3a4f9a1f5bc84386a4 (MD5) Previous issue date: 2009-05-18 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In most cultures, dreams are believed to predict the future on occasion. Several neurophysiological studies indicate that the function of sleep and dreams is to consolidate and transform memories, in a cyclical process of creation, selection and generalization of conjectures about the reality. The aim of the research presented here was to investigate the possible adaptative role of anticipatory dreams. We sought to determine the relationship between dream and waking in a context in which the adaptive success of the individual was really at risk, in order to mobilize more strongly the oneiric activity. We used the entrance examination of the Federal University of Rio Grande do Norte (UFRN) as a significant waking event in which performance could be independently quantified. Through a partnership with UFRN, we contacted by e-mail 3000 candidates to the 2009 examination. In addition, 150 candidates were approached personally. Candidates who agreed to participate in the study (n = 94) completed questionnaires specific to the examination and were asked to describe their dreams during the examinaton period. The examination performance of each candidate in the entrance examination was provided by the UFRN to the researcher. A total of 45 participants reported dreams related to the examination. Our results show a positive correlation between performance on the examination and anticipatory dreams with the event, both in the comparison of performance on objective and discursive, and in final approval (in the group that not dreamed with the exam the rate of general approval, 22,45%, was similar to that found in the selection process as a whole, 22.19%, while for the group that dreamed with the examination that rate was 35.56%). The occurrence of anticipatory dreams reflectes increased concern during waking (psychobiological mobilization) related to the future event, as indicated by higher scores of fear and apprehension, and major changes in daily life, in patterns of mood and sleep, in the group that reported testrelated dreams. Furthermore, the data suggest a role of dreams in the determination of environmentally relevant behavior of the vigil, simulating possible scenarios of success (dream with approval) and failure (nightmares) to maximize the adaptive success of the individual / Nas mais diversas culturas, atribui-se aos sonhos a capacidade de prever o futuro. Diversos estudos neurofisiol?gicos indicam que a fun??o do sono e dos sonhos ? consolidar e transformar mem?rias, em um processo c?clico de cria??o, sele??o e generaliza??o de conjecturas sobre a realidade. Com o objetivo de investigar cientificamente a poss?vel fun??o antecipat?ria dos sonhos, buscamos descrever a rela??o entre sonho e vig?lia subseq?ente num contexto em que o sucesso adaptativo do indiv?duo realmente estivesse em risco, de modo a mobilizar mais fortemente a atividade on?rica. Utilizamos o exame vestibular da Universidade Federal do Rio Grande do Norte (UFRN) como evento significativo da vig?lia. Atrav?s de uma parceria com a UFRN, contatamos por e-mail 3000 candidatos ao Vestibular 2009. Al?m disso, 150 candidatos foram abordados pessoalmente. Os candidatos que aceitaram participar do estudo (n=94) preencheram question?rios espec?ficos sobre a prova e lhes foi solicitado que relatassem um sonho relacionado ? prova, caso algum houvesse ocorrido nos dias que a antecederam. O desempenho final de cada candidato no exame vestibular foi fornecido ao pesquisador pela UFRN. Ao todo 45 participantes relataram que sonharam com a prova. Nossos resultados mostram uma correla??o positiva entre o desempenho na prova e sonhos antecipat?rios com o evento, tanto na compara??o do desempenho nas provas objetivas e discursivas, quanto na aprova??o final (no grupo que n?o sonhou com a prova o ?ndice de aprova??o geral, 22,45%, foi semelhante ao encontrado no processo seletivo como um todo, 22,19%; j? para o grupo que sonhou com a prova esse ?ndice foi 35,56%). A ocorr?ncia desses sonhos antecipat?rios refletiu uma maior preocupa??o na vig?lia (mobiliza??o psicobiol?gica) em torno do evento futuro (maiores escores de medo e apreens?o, al?m de maiores altera??es no cotidiano, nos padr?es de humor e de sono). Al?m disso, os dados sugerem um papel importante dos sonhos na determina??o de comportamentos ecologicamente relevantes da vig?lia, simulando poss?veis cen?rios de sucesso (sonhar com aprova??o) e fracasso (pesadelos) para maximizar o sucesso adaptativo do indiv?duo

Estrutura central do hipocampo, o corno de Ammon pode ser subdividido em pelo menos três áreas: CA1, CA2 e CA3. Enquanto CA1 e CA3 foram extensamente estudados, dado o envolvimento do hipocampo em processos cognitivos como a memória e patológicos como a epilepsia, CA2 tem sido largamente ignorado na literatura. Entretanto, este campo possui características específicas, tanto neuroanatômicas como bioquímicas e fisiológicas, sendo resistente à indução de plasticidade e recebendo aferência específica do núcleo supramamilar do hipotálamo, envolvido na circuitaria geradora/mantenedora do ritmo teta, oscilações centrais ao funcionamento do hipocampo. O objetivo deste estudo foi, portanto, caracterizar no animal em livre movimentação os padrões de atividade eletrofisiológica nas três áreas do corno de Ammon bilateralmente. Os resultados demonstraram que CA2 possui, em média, intervalos entre disparos mais prolongados que CA1 e CA3 durante o sono de ondas lentas e o sono REM. Nestas fases do ciclo a coerência entre CA1-CA2 foi mais elevada que entre CA1-CA3 e CA2-CA3 nos três ratos avaliados, em três faixas de freqüência: teta (6 a 12 Hz), gama lento (30 a 50 Hz) e gama rápido (90 a 110 Hz) ipsilateralmente. A coerência entre campos contralaterais é predominante no teta, sendo quase zero nas demais freqüências. Estes resultados corroboram trabalhos recentes que apontam CA2 como área distinta e sugerem que esta pequena região do corno de Ammon possa exercer papéis importantes na modulação da atividade das demais estruturas hipocampais e parahipocampais em processos de memória e em patologias como a epilepsia / The Ammons horn, central structure of the hippocampus, can be subdivided in at least three regions: CA1, CA2 and CA3. While CA1 and CA3 have been extensively studied given the hippocampus involvement in cognitive processes such as memory and pathological ones such as epilepsy, CA2 remains largely ignored. However, this sector contains specific neuroanatomical, biochemical e physiological characteristics, being resistant to induction of plasticity and receiving a specific afference from the supramammillary nucleus in the hypothalamus, involved in the generation/maintenance of the theta rhythm, central oscillations to hippocampal functioning. Therefore, the objective of this study was to characterize electrophysiological patterns of interaction in the three areas of the Ammons horn bilaterally. Results revealed that CA2 has a mean interspike interval larger than CA1 and CA3 during slow wave and REM sleep. During these stages of the sleep-wake cycle, coherence between CA1-CA2 was higher than CA1-CA3 and CA2-CA3 in the three animals evaluated, in three frequency bands: theta (6 to 12 Hz), slow gamma (30 to 50 Hz) and fast gamma (90 to 110 Hz) ipsilaterally. Coherence between contralateral fields was predominant in the theta band and almost zero in other frequencies. These results add to some previous published data showing that CA2 is distinct from the other subfields and that this small region of the Ammons horn may exert important roles in modulating activity in the other hippocampal fields and parahippocampal regions during memory and pathologies such as epilepsy

Le trouble comportemental en sommeil paradoxal (TCSP) est caractérisé par des rêves intenses et une perte de l’atonie musculaire normalement présente au cours du sommeil paradoxal qui permet l’apparition de comportements oniriques isomorphiques au contenu des rêves. Quelques chercheurs ont étudié le contenu des rêves des patients atteints du TCSP, plusieurs ont trouvé une plus grande présence de thèmes menaçants et agressifs, d’autres ont obtenu des résultats plus mitigés. Ces études comportent des failles méthodologiques importantes, comme l’absence d’un groupe contrôle ou l’inclusion de patients consommant une médication psychoactive. La présence de rêves à caractère dysphorique a été associée, dans d’autres populations, à une psychopathologie marquée et à des difficultés émotionnelles, et cette association, quoiqu’inexplorée pourrait aussi être présente chez patients ayant un TCSP. La raison pour laquelle ces patients font des rêves plus dysphoriques est encore largement inconnue, de même qu’une partie des mécanismes qui génèrent les comportements oniriques. Le but du premier article de cette thèse était de mesurer l’alexithymie et la détresse des cauchemars chez les patients atteints du TCSP par rapport à des contrôles. Les résultats indiquent que les patients souffrent davantage d’alexithymie, et particulièrement d’une difficulté à identifier leurs émotions et qu’elle corrélait avec la détresse due aux cauchemars. Le second article estimait, à l'aide d'un questionnaire validé, la présence de rêves, la diversité des thèmes des rêves chez les patients et examinait leurs thèmes au cours de leur vie. Les patients rapportaient beaucoup plus de cauchemars et plus de thèmes à caractère menaçant, comme des agressions, des catastrophes, et des rêves où le rêveur a peu de contrôle. Le troisième article avait pour objectif de clarifier les écarts dans les résultats des études sur les rêves des patients, c'est-à-dire déterminer si l'agressivité rapportée par ces patients est vraiment une différence au niveau du contenu des rêves, ou s'il s'agit plutôt d'un problème dû à la détresse liée aux rêves. Un second objectif était de mesurer le degré de corrélation entre les comportements à l’éveil, comme les comportements miroirs, et les comportements oniriques chez les patients. L’article démontre que les patients ressentaient une plus grande détresse à l'éveil en lien avec leurs expériences oniriques et que leurs rêves étaient plus dysphoriques et contenaient plus d'anxiété. De plus, leurs résultats au questionnaire de comportements miroirs corrélaient avec la sévérité de leurs comportements oniriques, ce qui suggère que le système de neurones miroirs pourrait avoir une influence sur les manifestations de ces comportements chez les patients. Globalement, ces résultats suggèrent que des difficultés au niveau de la régulation émotionnelle pourraient expliquer à la fois les symptômes émotionnels à l’éveil et les difficultés nocturnes des patients. Nous suggérons qu'un déficit au niveau des régions régulatrices frontales pourrait être à la base des différentes difficultés éprouvées par les patients. De plus, il est possible que des anomalies au niveau du système de neurones miroirs aient à la fois un impact sur la capacité des patients à réguler leurs émotions, mais aussi sur les manifestations de comportements oniriques. / REM sleep behavior disorder (RBD) is a parasomnia characterized by vivid dreams and loss of muscle atonia usually present during REM sleep that allows the appearance of dream-enacting behaviors that are isomorphic to dream content. Several studies have examined the content of RBD patients’ dreams, many found a greater presence of threatening and aggressive themes, others obtained mixed results. Most studies had significant methodological shortcomings, such as a lack of a control group or the inclusion of patients taking psychoactive medication. Still, the presence of dysphoric dreams is associated with marked psychopathology and emotional regulation problems. Moreover, the reason why RBD patients have dysphoric dreams is largely unexplored, just as parts of the processes that generate the dream-enacting behaviors. The goal of the first article of this thesis was to measure alexithymia and nightmare distress among RBD patients compared to a control group. The results indicate that RBD patients suffer more from alexithymia, especially a greater difficulty in identifying their emotions and that this difficulty correlated with nightmare distress. The second article examined, using a validated questionnaire, the lifetime prevalences of patients’ typical dream themes, and estimated the presence of their dreams, nightmares and dream theme diversity. RBD patients reported significantly more nightmares than controls and more menacing themes, such as assaults, disasters, and where the dreamer lacks control. The third article was intended to clarify discrepancies in the results of studies on RBD dreams, that is, if the aggressiveness reported by patients is really a difference in dream content or rather a problem related to dream distress. A second objective was to measure the degree of correlations between waking-state behaviors such as mirror behaviors, and dream-enacting behaviours in RBD patients. RBD patients were found to have more dysphoric dreams, containing more anxiety. They were also feeling greater distress in reaction to their dream experiences than did controls. Moreover, their results on the mirror behavior questionnaire correlated with the severity of their dream-enacting behaviors, suggesting that the mirror neuron system could have an influence in the formation of these behaviors. Overall, these findings suggest that difficulties in emotional regulation could explain both patients’ daytime emotional symptoms (alexithymia, nightmare distress, depression, anxiety, fewer mirror behaviors) and nocturnal difficulties (nightmares and dysphoric dreams, threats in dreams). We suggest that a deficit in frontal regulatory regions could be the base of the different challenges faced by patients. More specifically, it is possible that abnormalities in the mirror neuron system have an impact on both patients' ability to regulate their emotions and the manifestation of dream-enacting behaviors.

The diagnosis of Parkinson’s disease (PD) follows the UK Brain Bank Criteria, which demands bradykinesia and one additional symptom, i.e. rigidity, resting tremor or postural instability. The latter is not a useful sign for the early diagnosis of PD, because it does not appear before Hoehn and Yahr stage 3. Early symptoms of PD which precede the onset of motor symptoms are hyposmia, REM sleep behavioral disorder, constipation, and depression. In addition, an increasing number of patients whose PD is related to a genetic defect are being described. Thus, genetic testing may eventually develop into a tool to identify at-risk patients. The clinical diagnosis of PD can be supported by levodopa or apomorphine tests. Imaging studies such as cranial CT or MRI are helpful to distinguish idiopathic PD from atypical or secondary PD. SPECT and PET methods are valuable to distinguish PD tremor from essential tremor if this is clinically not possible. Using all of these methods, we may soon be able to make a premotor diagnosis of PD, which will raise the question whether early treatment is possible and ethically and clinically advisable. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

No description available.

La douleur est une expérience subjective multidimensionnelle pouvant être modulée par plusieurs facteurs cognitifs. L’impact des attentes liées à une expérience douloureuse imminente a été largement étudié dans un contexte d’analgésie placebo et il a été suggéré que la présence d’attentes conscientes de soulagement est nécessaire à la production d’une réduction de douleur. Par ailleurs, certaines études cliniques ont observé une amélioration thérapeutique après l’administration d’un placebo, même lors du sommeil, ce qui suggère qu’un effet placebo peut être rencontré même en absence d’attentes explicites de soulagement. La première étude de cette thèse vise donc à examiner si une réduction de douleur, ainsi qu’une diminution des perturbations du sommeil associées à des stimulations nociceptives expérimentales, peuvent être rencontrées suite à l’induction d’attentes de soulagement nocturne. Les résultats démontrent qu’une réduction de douleur et des perturbations du sommeil a effectivement été rapportée rétrospectivement suite à l’application d’un placebo, De plus, le traitement placebo semble moduler la réactivité à la douleur expérimentale durant le sommeil, en fonction des stades de sommeil dans lesquelles les stimulations sont présentées. Bien que le développement d’une analgésie placebo repose sur la génération d’attentes de soulagement, il semble que l’exposition préalable à un traitement efficace augmente l’ampleur de l’effet, ce qui suggère que des phénomènes d’apprentissage associatif puissent également être impliqués dans la genèse de ces effets. Comme un rôle du sommeil à été montré dans l’apprentissage et la mémorisation de plusieurs aptitudes, l’objectif de la seconde étude était d’examiner la possibilité que la présence d’un épisode de sommeil entre l’induction et l’évaluation d’un effet placebo puisse renforcer l’intégration des attentes et par conséquent, favoriser la production d’effets dépendants des attentes. Les résultats ont effectivement montré que le sommeil augmente l’association entre les attentes et le soulagement, et que celles-ci semblent liées à la durée relative de sommeil REM mesurée suite à l’induction. Dans l’ensemble cette thèse démontre que le sommeil peut influencer la production d’une analgésie placebo, et ce, à plusieurs niveaux. / Pain is a multidimensional experience which can be modulated by many cognitive factors. The impact of expectations associated with an impending painful experience was largely studied in the context of placebo analgesia, and it was suggested that the presence of conscious relief expectation was necessary for the production of pain reduction. On the other hand, some clinical studies have observed therapeutic improvements following the administration of a placebo, even during sleep, which suggest that a placebo effect can be seen even in the absence of explicit relief expectation. The first study of this thesis aims at examining if a pain reduction, as well as a decrease in sleep disturbances associated with the experimental pain stimuli, can be seen following the induction of night-time expectations. The results indeed showed a significant reduction in pain and associated sleep disturbances evaluated retrospectively following the application of a placebo. In addition, placebo treatment appears to modulate responses to experimental pain during sleep, in a manner dependent of the sleep stage in which they are presented. Although the development of placebo analgesia relies on the production of relief expectations, previous exposure to efficient treatment appears to augment the magnitude of the effect. This suggests that associative learning processes might also be implicated in the genesis of these effects. As a role of sleep was shown in the learning of different aptitudes, the objective of the second study was to examine whether the presence of a sleep episode between the placebo induction and the evaluation of the effect can reinforce the integration of expectations and consequently, favour the production of expectation-dependent effects. The results show that sleep increases the association between expectation and relief, and that the level of expectation appears to be linked to the relative duration of REM sleep measured after the induction. Globally, this thesis demonstrates that sleep can influence placebo analgesia at many levels.

La présente thèse examine les liens entre le sommeil, la mémoire épisodique et les rêves. Dans une première étude, nous utilisons les technologies de la réalité virtuelle (RV) en liaison avec un paradigme de privation de sommeil paradoxal et de collecte de rêve en vue d'examiner l'hypothèse que le sommeil paradoxal et le rêve sont impliqués dans la consolidation de la mémoire épisodique. Le sommeil paradoxal a été associé au rappel des aspects spatiaux des éléments émotionnels de la tâche RV. De la même façon, l'incorporation de la tâche RV dans les rêves a été associée au rappel des aspects spatiaux de la tâche. De plus, le rappel des aspects factuels et perceptuels de la mémoire épisodique, formé lors de la tâche VR, a été associé au sommeil aux ondes lentes. Une deuxième étude examine l'hypothèse selon laquelle une fonction possible du rêve pourrait être de créer de nouvelles associations entre les éléments de divers souvenirs épisodiques. Un participant a été réveillé 43 fois lors de l'endormissement pour fournir des rapports détaillés de rêves. Les résultats suggèrent qu'un seul rêve peut comporter, dans un même contexte spatiotemporel, divers éléments appartenant aux multiples souvenirs épisodiques. Une troisième étude aborde la question de la cognition lors du sommeil paradoxal, notamment comment les aspects bizarres des rêves, qui sont formés grâce aux nouvelles combinaisons d'éléments de la mémoire épisodique, sont perçus par le rêveur. Les résultats démontrent une dissociation dans les capacités cognitives en sommeil paradoxal caractérisée par un déficit sélectif dans l'appréciation des éléments bizarres des rêves. Les résultats des quatre études suggèrent que le sommeil aux ondes lentes et le sommeil paradoxal sont différemment impliqués dans le traitement de la mémoire épisodique. Le sommeil aux ondes lentes pourrait être implique dans la consolidation de la mémoire épisodique, et le sommeil paradoxal, par l'entremise du rêve, pourrais avoir le rôle d'introduire de la flexibilité dans ce système mnémonique. / The present dissertation examines relationships between sleep, episodic memory and dreaming. In Articles I and II we use a novel virtual reality (VR) task in conjunction with a rapid eye movement (REM) sleep deprivation (REMD) paradigm and dream sampling to examine the hypothesis that REM sleep and dreaming are involved in the consolidation of episodic memory. REM sleep was associated with the successful recall of the spatial aspects of emotionally charged elements of the VR task. Similarly, dreaming was associated with improved performance on the spatial aspects of the recall task. Recall of the factual and perceptual aspects of episodic memories formed with the VR task was associated with increased slow wave sleep (SWS) during the post-exposure night. Overall, the results suggest that SWS is associated with the perceptual and factual aspects of episodic memories while REM sleep is not, a finding which may relate to observations that REM sleep dreaming is composed of deconstructed fragments of loosely associated episodic memories. Study II examines the hypothesis that a function of dreaming may be to create new associations between previously unrelated memory items. A participant, highly trained in introspection and mentation reporting, was awakened 43 times during theta bursts at sleep onset and provided detailed reports of resulting imagery and associated memory sources. This technique provided evidence that elements of distally related memory sources are brought together in temporal and spatial proximity within a novel context provided by the dream, suggesting a role for dreaming in memory processing. To allow for this possibility, we speculate that dreaming experiences may be functionally equivalent to waking experiences in their ability to induce neural plasticity. Study III addresses an aspect of this functional equivalence by examining if dream bizarreness is incompatible with behavioral and cognitive features associated with waking state experience-driven plasticity, i.e., whether the dreamer can act upon, emote and be motivated towards an element of the dream that is bizarre and that violates basic assumptions of physical reality. The results demonstrate a dissociation in cognitive ability during dreaming characterized by a selective deficiency in appreciating bizarreness in face of a maintained ability for logical thought. This finding thus addresses the problem of the wake-like mind reflecting upon dream bizarreness and suggests that dreaming is a state in which the cognitive aspects associated with synaptic plasticity (attention, emotion and motivation associated with believing a situation to be reality) are present while allowing for the presentation of memory item combinations which may transcend the limits of physical reality. The results of the four studies are discussed in light of how REM and SWS sleep stages are differentially involved in specific aspects of episodic memory (episodic replay vs. episodic novelty) and the possible role that dreaming, as a driver of synaptic plasticity, may have in these relationships.

Made available in DSpace on 2015-07-22T20:49:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-05-27 / Associação Fundo de Incentivo à Psicofarmacologia (AFIP) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Atualmente no mundo, a cirrose hepática é um problema clínico grave, além de ser considerada uma doença muito comum e com grande impacto na saúde pública. As alterações na cito-arquitetura do fígado nesta patologia provoca perda das funções deste órgão, com várias conseqüências ao paciente. As manifestações clínicas da cirrose hepática são diversas e produzem alterações nas funções biológicas, como sono e vigília. Objetivo do estudo: Caracterizar os parâmetros do sono e sonolência diurna através do uso de questionários e de estudo polissonográfico completo em um grupo de cirróticos e compará-los com grupo de voluntários sem hepatopatia e verificar a possível influência da gravidade da doença hepática sobre parâmetros do sono e sonolência diurna. Casuistica e metodologia: O estudo foi caso-controle; os pacientes foram provenientes do ambulatório de cirrose hepática, do departamento de gastroenterologia do Hospital São Paulo, com diagnóstico confirmado de cirrose hepática. Foi selecionados 42 pacientes com cirrose e 42 controles sem hepatopatia. Todos os voluntarios fizeram polissonografia de noite inteira e também responderam questionários sobre o sono e a Escala de Sonolência de Epworth. A gravidade da doença foi verificada pelo modelo prognóstico de Child-Turcotte-Pugh e MELD. Resultados: Não houve diferença na idade, gênero e IMC entre os pacientes e os voluntários. No entanto, os achados polissonográficos mostraram menor eficiência do sono, maior latência do sono, e também um aumento da latência do REM, e porcentagem de REM reduzida, no grupo cirrótico, quando comparado aos controles. Os pacientes também mostraram maior frequência de movimentos periódicos de membros que os controles. Em relação à gravidade da doença hepática, os pacientes foram classificados em Child A (16 indivíduos) Child B (17 indivíduos) e Child C (9 indivíduos). Houve diferença entre os grupos Child em relação à porcentagem do sono REM, significativamente menor no grupo C quando comparado ao grupo B e A e aumento da latência do REM, significativamente maior no grupo C. Conclusão: Os resultados sugerem que os pacientes com cirrose tinham um sono de pior qualidade quando comparados ao grupo-controle e maior ocorrência de movimentos periódicos de membros inferiores durante o sono. Foi observada também uma influência da gravidade da cirrose hepática nos resultados polissonográficos. / Hepatic cirrhosis is a serious public health issue in the world, since it was a very common disease, with a great impact. The occurrence of liver structural alterations has various consequences, including neurological ones. The patient with cirrhosis presents several clinical manifestations that involve alterations on his biological functions such as sleep and waking. Study objective: The aim of this study was to characterize sleep parameters and sleepiness in cirrhotic patients and to assess a possible influence the severity level of this disease on these parameters. Design: It was a case-control study. Setting: The hepatology outpatient service of Hospital São Paulo (UNIFESP/EPM) and Sleep Institute and diagnostic center of Associação Fundo de Incentivo à Psicofarmacologia (AFIP). 42 cirrhotic patients and 42 volunteers without hepatic disease were submitted to an all night polysomnographic evaluation. They also answered sleep questionnaires as well as the Epworth Sleepiness Scale. The severity of the illness was assessed by the prognostic model of Child-Turcotte-Pugh and MELD scores. Results: There was no difference in age, gender and BMI between cirrhotic patients and volunteers. However, the polysomnographic findings showed lower sleep efficiency, as well as an increase in the REM sleep latency and a lower REM sleep percentage in the cirrhotic group when compared with the control group. The cirrhotic patients also showed higher frequency of Periodic Limb Movements in Sleep than the controls. There was a significant difference among Child-Turcotte-Pugh groups in regard to REM sleep percentage, significantly lower in group C when compared to group B and group A. No significant differences were detected between the scores of both groups in the Epworth Scale. Conclusion: The findings suggest that cirrhotic patients had a worse quality of sleep when compared with the control group and higher occurrence of PLMS. There was also an influence of the severity of liver failure in some sleep parameters. / FAPESP/CEPID: 95/14303-3 / TEDE / BV UNIFESP: Teses e dissertações