L'obésité est depuis quelques années reconnue comme un des fléaux du XXIe siècle en affectant environ 10% de la population adulte mondiale. Le passage de l'obésité au stade de pandémie est le résultat de multiples facteurs dont une mauvaise hygiène alimentaire et une sédentarité croissante. La découverte récente de l'existence d'un état inflammatoire chronique au cours de l'obésité pouvant intervenir dans la physiopathologie de la maladie et de ses nombreuses complications fait aujourd'hui l'objet d'intenses investigations. Or, le tissu adipeux (TA) qui, parallèlement à son activité métabolique, possède également une activité sécrétoire intense, est un acteur majeur de ce syndrome inflammatoire. L'autotaxine (ATX), l'adiponectine et la résistine sont les médiateurs de l'inflammation sécrétés par le TA. Si le rôle de ces facteurs dans la régulation du métabolisme est bien établi, leurs effets sur d'autres organes ne sont pas toujours connus. Il est notamment intéressant d'étudier leurs effets dans le système nerveux central (SNC), les récepteurs de certains y étant présent. Dans ce contexte, nous avons dans un premier temps étudié l'effet de l'ATX sur le stress oxydant généré par le H2O2 (peroxyde d'hydrogène) et sur l'inflammation induit par le lipopolysaccharide (LPS) ou le trimethylétain (TMT) dans les cellules microgliales murines, cellules immunitaires résidentes du SNC. Nos résultats montrent pour la première fois, l'effet anti-oxydant et anti-inflammatoire de l'ATX sur les cellules microgliales. Chez la souris, le TMT affecte la région hippocampique du SNC et nous avons montré qu'il induit la production d'ATX après 5 jours d'une injection i.p. de TMT. Ce qui suggère un rôle important de l'ATX dans la régulation de l'homéostasie des microglies et du SNC ainsi que dans la neuroinflammation. L'effet du TMT sur l'inflammation produite par le TA a également été étudié et les résultats montrent que le TMT induit une réponse inflammatoire dans deux types cellulaires du TA : adipocytes et macrophages ainsi que dans le TA de souris obèse ob/ob. Ensuite, nous avons sous-cloné les ADNc de l'adiponectine et de la résistine dans des vecteurs d'expression eucaryote afin d'étudier leurs effets sur les cellules microgliales dans des conditions normales ou inflammatoires. Cette étude devrait permettre une meilleure compréhension de l'influence du TA sur le SNC et donc la relation entre l'obésité les maladies neurodégénérative afin de proposer de nouvelles approches thérapeutiques. / In the last years, Obesity has been considered a major health issue with around 10% of the world population affected. The causes of this pandemy are multiple, but include bad alimentary habits and an increasing settle way of life. The recent discovery that chronic inflammation during obesity was associated with this disease physiopathology and others complications is the center of many investigations. Adipose tissue (AT), in addition to its metabolic activity, has an intense secretory activity and is a main player in this inflammatory syndrome. Autotaxin (ATX), adiponectin and resistin are such mediators secreted by AT. These factors functions in metabolism regulation are well described, but their effects on others organs are not always known. As it has been shown that some of these factors receptors are present in the central nervous system (CNS), it is interesting to study their effects in this organ. In this context, we initially studied the effect of ATX on the oxidative stress generated by H2O2 (hydrogen peroxide) and inflammation induced by lipopolysaccharide (LPS) or trimethyltin (TMT) in murine microglial cells, resident immune cells of the CNS. Our results show for the first time, the anti-oxidant and anti-inflammatory effects of ATX in microglial cells. In mice, TMT affects hippocampal region of CNS and we showed that ATX RNA is up regulated in the hippocampus 5 days post TMT treatment. Our results suggest that ATX could be involved in the regulation of microglia homeostasis and in neuroinflammation. The effect of TMT on the inflammation produced by the AT has also been studied and the results show that TMT induces an inflammatory response in two cell types of AT: adipocytes and macrophages and in fat tissue from ob/ob mice.We then subcloned the cDNA of adiponectin and resistin in eukaryotic expression vectors to study their effects on microglial cells under normal or inflammatory conditions. This study should lead to better understanding of adipose tissue influence on the CNS and therefore the relationship between obesity and neurodegenerative diseases to develop new therapeutic approaches.

A research report submitted to the Faculty of Health Sciences, the University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Medicine in Child Health Neurodevelopment Johannesburg, 2013 / Human Immunodeficiency Virus (HIV) infection in infancy may influence the developing brain and lead to adverse neurodevelopmental consequences. We aim to describe the neurodevelopmental characteristics of a cohort of young children infected with HIV prior to antiretroviral therapy (ART) initiation and after achieving viral suppression. A retrospective analysis of data collected as part of a randomised equivalence trial between April 2005 and May 2009, at a hospital in Johannesburg, South Africa. 195 HIV-infected children under 2 years of age were assessed. A simple, inexpensive screening questionnaire (Ages and Stages Questionnaire - ASQ) was used to identify neurodevelopmental delays. The ASQ was administered prior to ART initiation, and again after viral suppression on a protease inhibitor-based regimen had been achieved. Median age pre-ART was 8.8 months (range 2.2 - 24.9), 53.9% were male. Mean time to viral suppression was 9.4 months (range 5.9 - 14.5) and the ASQ was administered to 108 caregivers at this time. Compared to pre-ART, at viral suppression, there was significant reduction in the proportion of children failing the gross motor (31.5% vs. 13%, p<0.01), fine motor (21.3% vs. 10.2%, p=0.02), problem solving (26.9% vs. 9.3%, p<0.001) and personal social (17.6% vs. 7.4%, p=0.02) domains. The proportion of children failing the communication domain was similar at each time point (14.8% vs. 12%, p=0.61). At time of viral suppression 10.2% failed at least one of the five domains. Achieving viral suppression on ART resulted in significant improvements in the neurodevelopmental function of young HIV-infected children, however, neurodevelopmental problems still persisted in a large proportion. Appropriate screening for neurodevelopmental delay and timely referral could help improve outcomes.

A vareniclina é uma substância química sintética utilizada para o tratamento de tabagismo; atua como agonista de receptores colinérgicos nicotínicos, em especial, como agonista parcial em receptores &#945;4&#946;2 e &#945;3&#946;4, e como agonista total do receptor &#945;7. Levando em consideração que há uma tendência de ampliação do uso clínico da vareniclina para o tratamento da dependência à diversas substâncias de padrão abusivo e que há poucos estudos relacionados aos seus efeitos sobre o comportamento, cognição e sistema motor, tornam-se necessários mais estudos sobre essa substância. Assim, no presente trabalho foram estudados os efeitos da exposição prolongada (28 30 dias) de ratos à vareniclina, avaliando-se o consumo de água e de ração, o ganho de peso e o comportamento animal, por meio dos testes de campo aberto, labirinto em cruz elevado, interação social, comportamento estereotipado, labirinto de Barnes e esquiva passiva. Ainda foram feitas as avaliações dos níveis de neurotransmissores e seus metabólitos em diferentes estruturas cerebrais, bem como avaliações hematológicas, bioquímicas séricas, urinárias e estudos anatomopatológicos e histopatológicos. Foram utilizadas três doses de vareniclina: 0,03 (dose terapêutica para o ser humano), 0,1 e 0,3 mg/kg, por via oral (gavagem). Os resultados mostraram que a exposição prolongada de ratos à diferentes doses de vareniclina não provocou toxicidade, uma vez que não houve alteração no consumo médio de água e de ração e no ganho de peso avaliados semanalmente. Quanto às avaliações comportamentais, observou-se leve aumento da atividade geral no campo aberto, bem como diminuição do tempo de interação social, não sendo capaz de alterar parâmetros neuroquímicos, hematológicos, bioquímicos séricos, urinários, anatomopatológicos e histopatológicos de ratos expostos à vareniclina. / Varenicline is a synthetic chemical used for the smoking addiction treatment; it acts as an agonist of nicotinic cholinergic receptors, in particular, as a partial agonist of receptors &#945;4&#946;2 and &#945;3&#946;4 and as a full agonist of the &#945;7 receptor. More studies about this substance are necessary, given that its clinical use is increasingly being applied to the treatment of addiction to a variety of abusive drugs. Moreover, there are few studies on vareniciline effects on behavior, cognition and the motor system. Thus, in this study the effects of prolonged (28-30 days) exposure of rats to varenicline were evaluated. It was analyzed the water and food consumption, the weight gain and the animal behavior, through open field, elevated plus maze, social interaction, stereotyped behavior, Barnes maze and passive avoidance tests. The neurotransmitter levels and their metabolites in different brain structures were measured and hematological, serum biochemistry, urinary evaluations and pathological and histological studies were carried out. We used three doses of varenicline: 0.03 (therapeutic dose for humans), 0.1 and 0.3 mg/kg orally (gavage). The results showed that prolonged exposure of rats to different doses of varenicline did not cause toxicity, since there were no changes in average weekly consumption of water or food nor body weight gain, which were measured weekly. As for behavioral assessments, there was a slight increase in overall activity in the open field as well as decreased time of social interaction. Varenicline was not able to change neurochemical, hematological, serum biochemical, urinary, pathology and histopathology parameters of rats.

O estresse é um fenômeno conservado e observado evolutivamente, que tem como objetivo assegurar a sobrevivência do indivíduo. Porém quando o organismo perde a capacidade de se autorregular, torna-se uma ameaça. Algumas psicopatologias, como ansiedade e depressão, sugerem o envolvimento dos sistemas CRF e noradrenérgico e de níveis elevados de GCs. Avaliamos nesse trabalho algumas alterações morfofisiológicas e comportamentais decorrentes da exposição do estresse crônico imprevisível (EI) em ratos machos. Avaliados 24 h após o último estímulo estressor, os animais submetidos ao EI apresentaram níveis elevados de corticosterona plasmática, de RNAm de CRF2 e expressão de GR em regiões encefálicas (LSi e VmH e LSi, CeA, BST e PVH, respectivamente). Essas alterações morfofisiológicas foram, em parte, decorrentes da ação de GCs e de NE. Não foram observadas alterações comportamentais quanto à anedonia e ansiedade. Dessa maneira, podemos dizer que o EI utilizado nesse estudo, foi capaz de induzir algumas alterações morfofisiológicas, porém não comportamentais. / While acute stress initiates neuronal responses that prepare an organism to adapt to challenges, chronic stress may lead to maladaptative responses that could result in diseases. Evidence suggests the involvement of CRF system and high corticosterone levels in stress-related psychiatric disorders such as anxiety and major depressive disorders. The aim of this work was to investigate whether chronic unpredictable stress (CUS) could modulate de CRF system, GR expression in the CNS and behavior in male rats. Results showed an increase in corticosterone plasmatic levels, CRF2 mRNA and GR expression in specific regions of the CNS (LSi e VmH e LSi, CeA, BST e PVH, respectively), associated with the limbic system at 24 h after the last stress session. The chronic treatment with an inhibitor of GCs synthesis (metyrapone) and adrenergic receptor antagonists (atenolol and phentolamine) prevented the CUS effects in CRF2 mRNA levels and GR expression. No anxiety or depression-like behavior was observed in rats submitted to CUS. We conclude that CUS cause biochemical alterations since the increase CRF2 mRNA levels and GR expression in limbic region, but these changes were not able to cause behavioral changes.

A formação da memória envolve aprendizagem, consolidação e recuperação de informações e seus processos envolvem circuitos neuronais do córtex, hipocampo e amígdala. A formação da memória de longa duração ocorre a partir da formação da LTP \'\'long term potentiation\'\' que é modulada por diversos sistemas de neurotransmissores, entre eles o sistema colinérgico. Sabe-se que a atividade física aumenta a produção de neurotrofinas levando à melhora de estados patológicos, aumenta a densidade de receptores nicotínicos alfa7 em células do hipocampo. Já foi relatado que o destreinamento por duas semanas leva à reversão dos efeitos benéficos cardiovasculares. Esse projeto avalia os efeitos do treinamento e do destreinamento físico em piscina, sobre a manutenção da memória de longa duração de camundongos fêmeas por determinação da densidade de receptores nicotínicos alfa7 e da neurotrofina BDNF,na região do hipocampo, que não demonstrou diferença significativa entre os grupos avaliados no trabalho. / The processes of memory formation involves learning, consolidation and retrieval of information and processes involving neuronal circuits in the cortex, hippocampus and amygdala. The formation of long term memory occurs through the formation of LTP - \"long term potentiation\" that is modulated by multiple neurotransmitter systems, including the cholinergic system. It is known that physical activity increases the production of neurotrophins leading to an improvement of pathological conditions, increases the density of nicotinic receptors on hippocampal cells alfa7. It has been reported that for two weeks detraining leads to the reversion of beneficial cardiovascular effects. This project evaluates the effects of physical training and detraining on swimming on the maintenance of long-term memory of female mice by determining the density of nicotinic receptors alfa7 and neurotrophin BDNF in hippocampus, than showed no significant differences among the groups at work.

Cone snails are carnivorous marine mollusks, utilizing their neuropeptide-rich venom for prey capture. The venom of Conus brunneus, a wide-spread Eastern Pacific vermivore, has not been extensively studied. In the current work, peptides from the dissected venom were characterized and tested using preliminary bioassays. Six peptides (A-F) were isolated and tested. Three peptide identities were determined by comparison with previously reported data: bru9a (A), bru3a (F), and an a-conotoxin (E). Preliminary screening in a stroke-related model of induced glutamate excitotoxicity in primary neuronal cells and PC12 cell cultures indicated potential neuroprotective activity of peptide fractions A, D, and F. Further testing is necessary to determine and verify structure, activity, target, and mechanism of action of the promising peptides from C. brunneus, which may prove effective neuropharmacological agents to treat stroke. / by Rebecca A. Crouch. / Thesis (M.S.)--Florida Atlantic University, 2013. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Serotonin syndrome (SS) is a drug-induced toxicity caused by an excess of serotonin (5-HT) in the central nervous system (CNS). The symptoms of the disorder range from mild to severe, with the severe state evoking life-threatening hyperthermia. Autonomic dysfunction is controlled in part by serotonin receptors, with the 5-HT2A receptor responsible for increasing core body temperature (Tcor). Our results show that the 5-HT2A receptors on the preoptic/anterior hypothalamus (PO/AH) and prefrontal cortex (PFC), in particular, are sensitive to changes in ambient temperature (Tamb). The toxic increase of 5-HT is postulated to occur due to the temperature-dependent activation of these receptors that promotes a positive feedback mechanism. Our results suggest that changes in Tamb can either exacerbate or alleviate the symptom and that this is mediated by the 5-HT2A receptors. Understanding the mechanism involved in elevating Tcor is imperative in treating and preventing the disorder. / by Swapna Krishnamoorthy. / Vita. / Thesis (M.S.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

Taurine is the second most abundant amino acid in the CNS after glutamate and its functions have been found largely related to intracellular calcium ([Ca2+]i) modulation, osmoregulation, membrane stabilization, reproduction and immunity. The action of taurine has also been implicated in neurotransmission and neuromodulation though its specific sites of action are not fully understood. Isolated retinal neurons from the larval tiger salamanders (Ambystoma tigrinum) were used as a model to study the neuromodulatory role of taurine in the CNS and to gain insights into its potential sites of action. A combination of techniques was used, including whole-cell patch clamp recording to study taurine's regulation of voltage-gated potassium (K+) and Ca2+ channels and Fluo-4AM Ca2+-imaging to study taurine's regulation of glutamate-induced [Ca2+] I,. Taurine was shown to suppress of glutamate-induced [Ca2+] l, in a dose dependent manner. This suppression was mostly sensitive to the glycine rece ptor antagonist Strychnine but insensitive to any GABA receptor antagonist. The remaining strychnine-insensitive effect was inhibited with the protein kinase A (PKA) inhibitor, PKI, suggesting that there was an additional metabotropic pathway. Moreover, using the protein kinase C (PKC) inhibitor, GF109203X, there was an enhancement in strychnine-insensitive taurine's regulation. Taurine inhibits voltage-gated Ca2+ channels in the retinal neurons and has a dual effect on voltage-gated K+ channels. Taurine causes an increase in K+ current amplitude which is further enhanced with PKI and blocked with GF109203X, suggesting that it is through a PKC-dependent pathway negatively controlled by PKA-dependent pathway. / There is a suppression of K+ current by taurine with intracellular application of GF109203X, suggesting that the reduction is through a PKA-dependent pathway. With both PKC and PKA inhibitors there is no longer an enhancement in maximum amplitude but a shift of volt dependence on a hyperpolarizing direction. Taurine's enhancement of K+ current is blocked by the Kv1.3 subtype antagonist Margatoxin, with Kv1.3 accounting for the majority of delayed-rectifier sustained current in bipolar and amacrine cells, as well as 50% of ganglion cells. Interestingly, the enhancement of K+ current by taurine is blocked by 5HT2A antagonist MDL11939, suggesting that activation of PKC is through this metabotropic serotonin receptor subtype. The suppression of voltage-gated Ca2+ channels is reversed with a combination of MDL11939 and the 5HT1A antagonist NAN-190. These results provide the evidence that the natural effect of taurine in the retinal neurons might be dependent on the activation of both 5HT1A and 5HT2A receptors. The high apparent activity of taurine on 5HT receptors could have important implication for the actions of taurine in central brain in which taurine has been known to be beneficial for improving mental health, as well as learning and memory processes. / by Simon Bulley. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

Performance during prolonged exercise capacity diminishes with increasing temperatures. The onset of fatigue under these conditions is not adequately explained by peripheral mechanisms. Recently, drugs which inhibit the reuptake of dopamine and noradrenaline in the brain have been found to improve exercise performance in warm conditions. The aim of this thesis was to further explore and characterise the role of these neurotransmitters during prolonged exercise in warm conditions by manipulating their reuptake or synthesis. The first series of experiments were designed to further investigate the effects of bupropion, a dopamine and noradrenaline reuptake inhibitor, which has been found to improve performance in warm conditions. To explore gender differences in response to acute bupropion administration, the effects of bupropion on prolonged exercise performance in warm conditions in women was investigated in Chapter 3. The results of this study suggest that during the follicular phase of the menstrual cycle, acute administration of bupropion improves exercise performance. To determine whether there are any dose-dependent effects of bupropion, the experiment in Chapter 4 was designed to test three different doses of bupropion. Exercise performance was only improved for the maximal dose, suggesting a threshold for the performance effects of bupropion. Catecholamine precursors do not appear to improve exercise performance as consistently as reuptake inhibitors. In agreement with previous studies, the dopamine precursor L-DOPA did not affect exercise performance in warm conditions in Chapter 5. In Chapter 6 the effect of the atypical antidepressant nutritional supplement S-adenosylmethionine was investigated for its role in the synthesis of dopamine and noradrenaline. S-adenosylmethionine appeared to negatively influence cognitive function, increased skin temperature and circulating prolactin concentrations, but no effects on exercise performance were observed.

A migrânea e a cefaléia tensional são cefaléias primárias que surgem de estruturas não-mastigatórias, porém, a presença de sintomas de DTM, como a dor, pode influenciar de modo excitatório tais condições e vice-versa, influenciando no resultado final do tratamento. Esta pesquisa tem o objetivo principal de avaliar o impacto da presença de cefaléias primárias no tratamento das Disfunções Temporomandibulares (DTMs), e testa a hipótese nula de que a presença de cefaléias primárias não interfere com o resultado do tratamento. Como objetivos secundários, de avaliar se existe diferença na presença de dor miofascial nos músculos mastigatórios e cervicais, se existe diferença entre a variação da dor medida pela Escala Analógica Visual (EAV) em relação ao gênero, estresse e hábitos parafuncionais, e se essa diferença também se apresenta entra as variáveis oclusão, tempo de dor, número de queixas e número de tratamentos indicados. Para isso foram selecionados 546 prontuários clínicos de pacientes, sendo 313 com DTM e 233 com DTM e cefaléias, e analisados segundo a EAV ao início e fim do tratamento para DTM, bem como a variação entre a dor inicial e final entre os grupos. Testes de Mann-Whitney, Correlação de Spearman e Qui-quadrado analisaram os dados, com 5% de significância. A presença de cefaléias primárias interferiu negativamente no índice de sucesso do tratamento da DTM (p<0,05) (redução de 38,70 e de 24,66 na EAV para os grupos de DTM e DTM associada a cefaleia, respectivamente). A presença de dor miofascial nas musculaturas mastigatória e cervical foi semelhante entre os grupos. A variação entre a dor inicial e final não foi afetada pela diferença entre os gêneros, assim como pelo auto-relato da presença de hábitos parafuncionais e de estresse. Da mesma forma, a presença de má-oclusão, o tempo de experiência de dor, o número de queixas relatadas e o número de tratamentos indicados pelo profissional não influenciaram os resultados finais. Conclui-se que presença de cefaléias primárias parece interferir negativamente na melhora do quadro sintomático de pacientes tratados para DTM. / Migraine and tension-type headaches are primary headaches that arise from non-masticatory structures, however, the presence of TMD symptoms, like pain, may have a excitatory effect in these conditions and vice versa, influencing the outcome of treatment. This research has the main objective of evaluating the impact of the presence of primary headache in the treatment of Temoromandibulares Disorders (TMD), and tests the null hypothesis that the presence of primary headache does not interfere with treatment outcome. As secondary objectives, to evaluate whether there are differences in the presence of myofascial pain in the masticatory and cervical muscles, if there is a difference between the change in pain measured by visual analog scale (VAS) in relation to gender, stress, and parafunctional habits. The influence of malocclusion, duration of pain, number of complaints and number of treatments given were also evaluated. For this reason, 546 medical records of patients, 313 and 233 with TMD TMD and headaches were selected, and analyzed using a VAS at the beginning and end of treatment for TMD, as well as the variation between the initial and final pain between the groups. Mann-Whitney, Spearman correlation and chi-square test analyzed the data with 5% significance level. The presence of primary headaches interfered negatively with the rate of successful treatment of TMD (p <0,05) (reduction of 38.70 and 24,66 in the VAS for groups of TMD and headache associated with TMD, respectively). The presence of myofascial pain in the masticatory and cervical muscles was similar between groups. The variation between the initial and final pain was not affected by gender differences, as well as by self-report the presence of parafunctional habits and stress. Likewise, the presence of malocclusion, time of pain experience, the number of complaints reported and the number of treatments given by the professional did not influence the final results. It is concluded that the presence of primary headache seems to have a negative effect on symptomatic improvement in patients treated for TMD.