Over the course of a typical night, sleep is comprised of multiple different stages that involve changes in brainwave patterns. Intracranial EEG (iEEG) is an invasive brain recording technique used in hospital settings in epileptic patients to determine the focus of their seizure activity. The intracranial data recorded allows one to directly observe the neural activity of deep brain structures such as the hippocampus and to detect single unit activity and local field potentials, thus providing a level of physiological detail normally available only in animal studies. In this thesis we employ intracranial data to advance our understanding of sleep neural dynamics in humans, and to this end its focus is in two areas : (1) developing a way of sleep scoring iEEG data and (2) investigating the neural dynamics of a particular waveform found during sleep, the sleep spindle, and its role in memory consolidation. Typically, iEEG recordings do not include electrooculogram or electromyogram recordings, which are normally needed for sleep scoring—especially for scoring rapid-eye movement (REM) sleep. We identified differences in alpha power between wake and REM sleep to develop a methodological way to reliably differentiate between wake and REM sleep states. We also wanted to investigate the neural dynamics involved with a particular brainwave seen during sleep, the sleep spindle, which is thought to be important for sleep-mediated memory consolidation. Historically, sleep spindles were thought to occur synchronously across the cortex, but recent findings using iEEG have identified that sleep spindles can also be local. We utilized intracranial EEG to confirm previous findings that iEEG can identify local sleep spindles. In addition to identifying local sleep spindles, we aimed to investigate the potential role that sleep spindles have on learning and memory using standard targeted memory reactivation paradigms for iii both procedural and declarative memories. We found that local sleep spindles occurred at a specific time following auditory stimulation for both procedural and declarative memories. This work has opened up the use of iEEG recordings to investigations of REM sleep dynamics and laid the groundwork for examining the role of local sleep spindles in memory consolidation. / Master of Science / During a night of sleep, our brain goes through different stages that exhibit changes in brainwave patterns. Intracranial EEG (iEEG) is an invasive brain recording technique used in hospital settings in epileptic patients to determine the focus of their seizure activity; this particular brain recording technique allows one to observe the brain activity of deep brain structures. By using iEEG data, we aimed to (1) develop a way of sleep scoring iEEG data and (2) investigate the neural dynamics of a particular waveform found during sleep, the sleep spindle, and its role in memory consolidation.  Electrooculograms (EOG) are used to record the electrical activity of eye movements, and electromyograms (EMG) are used to measure muscle activity. Both of these recording techniques, in addition to EEG, are needed for sleep scoring, especially rapid eye movement (REM) sleep. However, typical iEEG recordings do not have EOGs and EMGs applied to the patient. Using iEEG data, we were able to identify differences in a specific brainwave, the alpha rhythm, between wakeful brain activity and REM sleep brain activity. Furthermore, we were able to use this difference to reliably score REM sleep in iEEG data without the need for EOGs and EMGs.  We also wanted to investigate the brainwave changes in a particular waveform, the sleep spindle, that has been thought to be important for sleep-mediated memory consolidation. Previous research using typical EEG recordings showed that sleep spindles occur synchronously across the cortex, but recent findings using iEEG have identified that sleep spindles can also occur asynchronously across the cortex. We replicated previous research showing that these local sleep spindles are identifiable using iEEG recordings. In addition to identifying local sleep spindles, we investigated the potential role that sleep spindles have on learning and memory. To do so, we used standard targeted memory reactivation paradigms for two types of memory: declarative and procedural memory. We found that local sleep spindles occurred at a specific time following auditory stimulation for both procedural and declarative memories.  This work has opened up the use of iEEG recordings to investigations of REM sleep dynamics and laid the groundwork for examining the role of local sleep spindles in memory consolidation.

La schizophrénie découle d’une modification du fonctionnement du cerveau et entraîne divers symptômes qui ont pour conséquence une altération de la perception de la réalité, des troubles cognitifs, et des dysfonctionnements sociaux et comportementaux. En plus des observations cliniques de jour, la schizophrénie montre également des signes nocturnes qui peuvent se manifester durant le rêve. Cette thèse vise à caractériser les rêves dans la schizophrénie et cherche à explorer les relations qui existent entre les caractéristiques du contenu onirique des personnes atteintes de schizophrénie et les symptômes de cette maladie. Pour ce faire, nous avons comparé diverses mesures de l’activité onirique recueillies auprès de 14 participants atteints de schizophrénie traités sous antipsychotiques atypiques et 15 participants témoins par le biais de questionnaires et de collectes de rêves en laboratoire à la suite d’éveils provoqués en sommeil paradoxal (SP) et en sommeil lent (SL). Les résultats obtenus au questionnaire révèlent que les participants atteints de schizophrénie rapportent un nombre de cauchemars plus élevé comparativement aux participants témoins. Les collectes en laboratoire démontrent une fréquence de rappel de rêves équivalente au sein des deux groupes de participants, indépendamment du stade de sommeil durant lequel elles sont effectuées. Les récits de rêves du SL des deux groupes de participants sont généralement plus courts et comprennent un nombre moins élevé d’items quantifiables comparativement à ceux du SP. Les récits de rêves recueillis en SP et en SL chez les participants atteints de schizophrénie s’avèrent plus courts que ceux des participants témoins et, lorsque le nombre de mots est pondéré, la plupart des différences observées dans le contenu de rêve entre les deux groupes tendent à disparaître. En comparaison aux participants témoins, ceux atteints de schizophrénie évaluent leurs rêves comme étant moins bizarres, en dépit d’un nombre équivalent d’éléments bizarres dans leurs récits. Finalement, bien qu’il n’y ait pas de différence dans la densité des mouvements oculaires rapides (MORs) entre les deux groupes de participants, seuls les participants témoins montrent une corrélation positive entre les MORs et certaines variables du contenu onirique. Les résultats de la présente thèse suggèrent que les caractéristiques du contenu onirique des personnes atteintes de schizophrénie peuvent refléter certaines des manifestations psychopathologiques de cette maladie. / Schizophrenia is a chronic, severe, and disabling brain disease which is characterized by symptoms which cause altered reality perception, cognitive deficits, and impairment in social or vocational functioning. In addition to clinical symptoms, schizophrenia can be accompanied with nocturnal characteristics which could manifest during dreaming. Using both questionnaire-based measures and laboratory REM sleep and non-REM sleep awakenings, we sought to characterize the dream content of 14 participants with schizophrenia under atypical antipsychotic medication. Results were compared with those from 15 healthy individuals. The relationship between dream content and daytime functioning in schizophrenia was also explored. Questionnaire data revealed that when compared to controls, patients with schizophrenia report experiencing a greater number of nightmares. Laboratory awakenings revealed that there was no significant difference between the two groups in the number of dream reports with reportable content, regardless of the sleep stage in which dreams were collected. In addition, when compared to their REM dream counterparts, both groups’ non-REM dream reports were shorter and included significantly fewer reportable items on several content scales. Laboratory REM and non-REM dream narratives from the patients were shorter and, after controlling for report length, most significant differences in dream content between the two groups disappeared. Patients with schizophrenia spontaneously rated their dream reports as being less bizarre than did controls, despite a similar density of bizarre elements as scored by external judges. Finally, both groups had a comparable density of rapid eye movements during REM sleep but a significant positive correlation between eye-movement density and dream content variables was only found in controls. Taken together, these findings suggest that dream content characteristics in schizophrenia may reflect psychopathological parameters specific to this disorder.

La schizophrénie découle d’une modification du fonctionnement du cerveau et entraîne divers symptômes qui ont pour conséquence une altération de la perception de la réalité, des troubles cognitifs, et des dysfonctionnements sociaux et comportementaux. En plus des observations cliniques de jour, la schizophrénie montre également des signes nocturnes qui peuvent se manifester durant le rêve. Cette thèse vise à caractériser les rêves dans la schizophrénie et cherche à explorer les relations qui existent entre les caractéristiques du contenu onirique des personnes atteintes de schizophrénie et les symptômes de cette maladie. Pour ce faire, nous avons comparé diverses mesures de l’activité onirique recueillies auprès de 14 participants atteints de schizophrénie traités sous antipsychotiques atypiques et 15 participants témoins par le biais de questionnaires et de collectes de rêves en laboratoire à la suite d’éveils provoqués en sommeil paradoxal (SP) et en sommeil lent (SL). Les résultats obtenus au questionnaire révèlent que les participants atteints de schizophrénie rapportent un nombre de cauchemars plus élevé comparativement aux participants témoins. Les collectes en laboratoire démontrent une fréquence de rappel de rêves équivalente au sein des deux groupes de participants, indépendamment du stade de sommeil durant lequel elles sont effectuées. Les récits de rêves du SL des deux groupes de participants sont généralement plus courts et comprennent un nombre moins élevé d’items quantifiables comparativement à ceux du SP. Les récits de rêves recueillis en SP et en SL chez les participants atteints de schizophrénie s’avèrent plus courts que ceux des participants témoins et, lorsque le nombre de mots est pondéré, la plupart des différences observées dans le contenu de rêve entre les deux groupes tendent à disparaître. En comparaison aux participants témoins, ceux atteints de schizophrénie évaluent leurs rêves comme étant moins bizarres, en dépit d’un nombre équivalent d’éléments bizarres dans leurs récits. Finalement, bien qu’il n’y ait pas de différence dans la densité des mouvements oculaires rapides (MORs) entre les deux groupes de participants, seuls les participants témoins montrent une corrélation positive entre les MORs et certaines variables du contenu onirique. Les résultats de la présente thèse suggèrent que les caractéristiques du contenu onirique des personnes atteintes de schizophrénie peuvent refléter certaines des manifestations psychopathologiques de cette maladie. / Schizophrenia is a chronic, severe, and disabling brain disease which is characterized by symptoms which cause altered reality perception, cognitive deficits, and impairment in social or vocational functioning. In addition to clinical symptoms, schizophrenia can be accompanied with nocturnal characteristics which could manifest during dreaming. Using both questionnaire-based measures and laboratory REM sleep and non-REM sleep awakenings, we sought to characterize the dream content of 14 participants with schizophrenia under atypical antipsychotic medication. Results were compared with those from 15 healthy individuals. The relationship between dream content and daytime functioning in schizophrenia was also explored. Questionnaire data revealed that when compared to controls, patients with schizophrenia report experiencing a greater number of nightmares. Laboratory awakenings revealed that there was no significant difference between the two groups in the number of dream reports with reportable content, regardless of the sleep stage in which dreams were collected. In addition, when compared to their REM dream counterparts, both groups’ non-REM dream reports were shorter and included significantly fewer reportable items on several content scales. Laboratory REM and non-REM dream narratives from the patients were shorter and, after controlling for report length, most significant differences in dream content between the two groups disappeared. Patients with schizophrenia spontaneously rated their dream reports as being less bizarre than did controls, despite a similar density of bizarre elements as scored by external judges. Finally, both groups had a comparable density of rapid eye movements during REM sleep but a significant positive correlation between eye-movement density and dream content variables was only found in controls. Taken together, these findings suggest that dream content characteristics in schizophrenia may reflect psychopathological parameters specific to this disorder.

A leading theory for why we sleep focuses on memory consolidation - the process of stabilizing and strengthening newly acquired memories into long-term storage. Consolidation of memory for cognitive strategies and problem-solving skills is enhanced as compared to a period of daytime wakefulness. Importantly, sleep preferentially enhances memory for the cognitive strategy per se, over-and-above the motor skills that are used to execute the strategy. Although it has been known for some time that sleep benefits this type of memory, it is not known how this process unfolds during sleep, or how sleep transforms this memory trace in the brain. Sleep is classified into rapid eye movement (REM) sleep and non-REM (NREM) sleep. The role of REM sleep for consolidation of memory for problem-solving skills remains controversial. In addition, little attention has been paid to the possible distinct roles of phasic REM sleep (i.e., when bursts of eye movements occur) and tonic REM sleep (i.e., the presence of isolated eye movements and the absence of eye movement bursts). REM sleep might favour procedural memory consolidation for cognitive strategies and problem-solving skills, and the specific role of REM sleep in this process might be discernible only by differentiating between phasic and tonic REM states. In addition, fMRI studies have revealed that sleep-related consolidation of the memory trace for simple motor procedural skills is associated with strengthened activity of, and functional connectivity between, key memory-related brain areas (i.e., hippocampal, striatal, and neocortex). However, fMRI techniques have not yet been employed to investigate sleep-related consolidation of procedural memory for cognitive strategies and problem-solving skills. Participants (n=60) performed a procedural memory task involving a cognitive strategy while undergoing functional magnetic resonance imaging (fMRI) before and after a condition of Sleep, Nap, or Wake. Those in the Sleep and Nap condition underwent polysomnography (PSG) to further study the learning-related changes in sleep macrostructure and microstructure. This thesis not only shows that a period of sleep or a nap afford a greater benefit to memory consolidation of a procedural strategy than a period of wake, but more specifically: In Study 1, during sleep, phasic REM sleep theta power was directly associated with overnight improvement on the task, whereas tonic REM sleep sensorimotor rhythm power was greater following a night of learning compared to a non-learning control night. In Study 2, we show that distinct hippocampal, striatal, and cortical areas associated with strategy learning are preferentially enhanced. Study 3 reveals that the functional communication among these brain areas is greater following sleep compared to a daytime nap or day of wakefulness. Sleep-related changes in brain activation and functional connectivity were both correlated with improved performance from before to after a period of sleep. Overall, findings from this thesis support the benefit of sleep at the behavioural and systems level for consolidating procedural memory involving cognitive strategies used to solve problems. The findings suggest that the multifaceted nature of REM sleep must be examined separately by its phasic and tonic states, to identify the active role of REM sleep for consolidating memory. Further, the consolidation of the memory trace is reflected through activation of, and communication between hippocampal, striatal, and neocortical brain areas. In summary, this thesis shows that sleep actively consolidates memory for cognitive strategies and problem-solving skills.

L’objectif de notre étude est d’améliorer la connaissance des réseaux neuronaux responsables de la régulation du sommeil paradoxal (SP). Dans ce but, nous avons combiné des techniques de polysomnographie, de neuroanatomie fonctionnelle, de pharmacologie et de traçage de voies nerveuses. Nous avons ainsi mis en évidence une population de neurones GABAergiques à la jonction entre la substance grise périaqueductale ventrolatérale et la partie dorsale du noyau profond du mésencéphale (vlPAG/dDpMe), capable de bloquer l’entrée en SP. Nous avons également démontré l’existence de nombreuses populations de neurones GABAergiques pontiques activés au cours du SP. De plus, nos travaux ont révélé la présence de nombreux neurones GABAergiques, dont les neurones à MCH, actifs en SP dans plusieurs régions hypothalamiques. Enfin, nous avons établi une cartographie des neurones à MCH et à Hcrt envoyant des projections sur les neurones histaminergiques du noyau tubéromammillaire ventral (VTM), promoteurs de l’éveil. L’ensemble de notre travail de thèse a permis d’affiner le modèle des réseaux neuronaux impliqués dans la régulation du SP, particulièrement en confirmant le rôle du GABA dans ces mécanismes de régulation / The aim of our study is to improve the knowledge of the neural networks responsible for paradoxical sleep (PS) regulation. To this end, we combined polysomnographic recordings, functional neuroanatomy, pharmacology and tract-tracing of nervous pathways. We thus highlighted a population of GABAergic neurons at the junction between the ventroleral periaqueductal gray and the dorsal part of the deep mesencephalic nucleus (vlPAG/dDpMe), able to gate PS genesis. We also showed the existence in the pons of several GABAergic neurons populations activated during PS. Moreover, our work revealed the presence of a large number of GABAergic neurons including the MCH neurons, activated in PS in several hypothalamic areas. Finally, we mapped the MCH, Hcrt neurons that send projections to the wake-promoting histaminergic neurons of the ventral tuberomammillary nucleus (VTM). Our thesis work made it possible to refine the model of neural networks involved in PS regulation, particularly by confirming the role of GABA in these mechanisms of regulation.

Após a lesão medular (LM) ocorre reorganização estrutural local e em múltiplos níveis do sistema nervoso central (SNC). Comprometimento das funções sensório-motoras bem como alterações significativas de outras funções neurais são normalmente relatadas após um trauma seguido de LM. Os ritmos circadianos, em especial, o ciclo vigília-sono são freqüentemente afetados após um trauma ou intervenção no SNC, no entanto, poucos estudos tem relacionado a influência da lesão medular sobre a fisiologia do sono. Estudos fisiopatológicos são atualmente baseados em modelos experimentais os quais tem possibilitado o esclarecimento dos mecanismos subjacentes a vários fenômenos biológicos. Dessa forma, o presente estudo teve como objetivo apresentar, primeiramente, uma análise sistemática do ciclo vigíliasono em um modelo animal de LM contusa moderada e, em segundo lugar, por ser o sono dessincronizado uma fase importante pela ocorrência de movimentos espontâneos, estudar detalhamente a influencia da LM sobre os eventos tônicos e fásicos desta fase. Para tal, foram realizados registros eletroscilográficos das áreas corticais sensório-motora (A7) e hipocampais (CA1) de ambos os hemisférios e, registros eletromiográficos dos trapézios, elevadores da asa do nariz, gastrocnêmios e epicantos oculares. Os resultados mostraram significativo aumento na quantidade total das fases sono sincronizado (p<0,002, Dunn) e SD (p<0,03, Dunn), bem como, presença dos eventos fásicos inerentes ao SD após a lesão medular. A arquitetura dos ciclos sofreu forte influencia da LM manifestada pela desorganização das fases (p<0.05). Os resultados apresentados neste estudo demonstraram que o trauma medular provoca alterações qualitativas e quantitativas nos ciclos vigília-sono dos ratos portadores LM contusa moderada. / After a spinal cord injury (SCI), structural reorganization occurs locally and at multiple levels of the central nervous system (CNS). Compromising of sensory motor functions and significant alterations of other neural functions are normally related after a SCI. The circardians rhythms, specially the sleep-wake cycle are frequently affected after a trauma or intervention in CNS. Few studies have approached contusive SCI in sleep physiology. Nowadays, physiopatological studies are based on experimental models which offer several possibilities to obtain new signs related to mechanisms to several biological phenomena. Thus, the present research aimed to present a systematic analysis of the sleep-wake cycle in a SCI animal model to detail the influence of SCI over tonic and phasic events during desynchronized sleep (DS), since this sleep phase is important for the occurrence of spontaneous movements. In order to do that, electroencephalogram (EEG) records of the sensory motor cortex (A7) and dorsal hippocampus (CA1) of both hemispheres were carried out, and electromyography (EMG) records of the trapezium, rostrum, gastrocnemius and eyes. The results showed significant increase of total time of synchronized sleep (p<0.002) and DS (p<0.03) and evidence of phasic events inherent to DS after SCI. The cycle architecture suffered high influence of SCI manifested by disarrangement of phases (p<0.05). The results presented in this study showed that SCI provokes qualitative and quantitative alterations of sleep-wake cycle in contusive moderate SCI rats.

Após a lesão medular (LM) ocorre reorganização estrutural local e em múltiplos níveis do sistema nervoso central (SNC). Comprometimento das funções sensório-motoras bem como alterações significativas de outras funções neurais são normalmente relatadas após um trauma seguido de LM. Os ritmos circadianos, em especial, o ciclo vigília-sono são freqüentemente afetados após um trauma ou intervenção no SNC, no entanto, poucos estudos tem relacionado a influência da lesão medular sobre a fisiologia do sono. Estudos fisiopatológicos são atualmente baseados em modelos experimentais os quais tem possibilitado o esclarecimento dos mecanismos subjacentes a vários fenômenos biológicos. Dessa forma, o presente estudo teve como objetivo apresentar, primeiramente, uma análise sistemática do ciclo vigíliasono em um modelo animal de LM contusa moderada e, em segundo lugar, por ser o sono dessincronizado uma fase importante pela ocorrência de movimentos espontâneos, estudar detalhamente a influencia da LM sobre os eventos tônicos e fásicos desta fase. Para tal, foram realizados registros eletroscilográficos das áreas corticais sensório-motora (A7) e hipocampais (CA1) de ambos os hemisférios e, registros eletromiográficos dos trapézios, elevadores da asa do nariz, gastrocnêmios e epicantos oculares. Os resultados mostraram significativo aumento na quantidade total das fases sono sincronizado (p<0,002, Dunn) e SD (p<0,03, Dunn), bem como, presença dos eventos fásicos inerentes ao SD após a lesão medular. A arquitetura dos ciclos sofreu forte influencia da LM manifestada pela desorganização das fases (p<0.05). Os resultados apresentados neste estudo demonstraram que o trauma medular provoca alterações qualitativas e quantitativas nos ciclos vigília-sono dos ratos portadores LM contusa moderada. / After a spinal cord injury (SCI), structural reorganization occurs locally and at multiple levels of the central nervous system (CNS). Compromising of sensory motor functions and significant alterations of other neural functions are normally related after a SCI. The circardians rhythms, specially the sleep-wake cycle are frequently affected after a trauma or intervention in CNS. Few studies have approached contusive SCI in sleep physiology. Nowadays, physiopatological studies are based on experimental models which offer several possibilities to obtain new signs related to mechanisms to several biological phenomena. Thus, the present research aimed to present a systematic analysis of the sleep-wake cycle in a SCI animal model to detail the influence of SCI over tonic and phasic events during desynchronized sleep (DS), since this sleep phase is important for the occurrence of spontaneous movements. In order to do that, electroencephalogram (EEG) records of the sensory motor cortex (A7) and dorsal hippocampus (CA1) of both hemispheres were carried out, and electromyography (EMG) records of the trapezium, rostrum, gastrocnemius and eyes. The results showed significant increase of total time of synchronized sleep (p<0.002) and DS (p<0.03) and evidence of phasic events inherent to DS after SCI. The cycle architecture suffered high influence of SCI manifested by disarrangement of phases (p<0.05). The results presented in this study showed that SCI provokes qualitative and quantitative alterations of sleep-wake cycle in contusive moderate SCI rats.

Emotion is thought to modulate the long-term fate of memories. Experiences that elicit an emotional response tend to be better remembered than comparatively unemotional events, while the emotional charge associated with these memories diminishes over time. Sleep – in particular rapid-eye movement (REM) and slow-wave sleep (SWS) - has been implicated in both the selective strengthening and affective uncharging of emotional memories. According to the sleep to forget, sleep to remember (SFSR) hypothesis, both processes occur in parallel during REM sleep. Although evidence strongly supports a role of REM sleep in the selective consolidation of emotional memories, it is far less clear to what extent sleep is involved in the development of emotional charge. While some studies support a primary role of REM in habituation (i.e. the decrease of emotional charge), others suggest a more central role of SWS. Further, existing literature indicates that the physiological (bottom-up) and cognitive (top-down) components of emotional responses may be differentially processed across sleep. Chapter 2 proposes complementary functions of REM and SWS in emotional memory processes based on a combination of evidence from rodent and human research. The experiments presented in this thesis employed polysomnography (PSG), subjective arousal testing, pupillometry, targeted memory reactivation (TMR), and transcranial alternating current stimulation (tACs) to investigate the respective roles of REM and SWS in the overnight development of subjective and autonomic arousal in response to negative emotional and neutral stimuli. In Chapter 3 I assessed how subjective and autonomic responses to neutral and negative stimuli develop across 12 hours containing either nocturnal sleep or daytime wakefulness. I found that autonomic reactivity – indexed by pupil dilation – decreased across sleep but not wake, while subjective arousal did not change across either interval. In a further experiment, I investigated whether the placement of sleep within a 24 hour interval would affect habituation. Once again, autonomic arousal decreased significantly. Subjective arousal towards negative stimuli was found to decrease more if sleep followed rather than preceded daytime wakefulness within the 24 hour interval. In Chapter 4 I explored the role of REM sleep in emotional habituation by applying 5 Hz tACs in an attempt to entrain endogenous cortical theta (4-7 Hz) activity, which has previously been associated with emotional memory consolidation in humans. Surprisingly, I found that stimulation was associated with a reduction in theta power and no change in subjective or autonomic habituation compared to the sham control night. In Chapters 5 and 6, I addressed the contribution of memory reactivations during SWS and REM sleep, respectively, in emotional habituation using TMR. In Chapter 5, I found that TMR was associated with a decrease and simultaneous increase in autonomic habituation towards negative and neutral stimuli, respectively, without affecting overnight changes in subjective arousal. In contrast, in Chapter 6, TMR during REM sleep was associated with an increase in subjective habituation towards both neutral and negative stimuli without affecting autonomic responses. In conclusion, my results provide new insights to the role of sleep in emotional habituation. I have provided evidence that targeted memory reactivation during REM sleep can modulate the development of cognitive evaluations of emotion, while TMR during SWS may interfere with autonomic habituation. This suggests distinct emotional processing during REM and SWS, as well as a dissociation between subjective and autonomic habituation across sleep. These results are discussed in the light of previous research and the model of sleep-dependent emotional memory processing proposed in Chapter 2.

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